An overview of the Open Source CubeSat Workshop 2021 that took place in December.
SDRmakerspace is a European Space Agency activity implemented by Libre Space Foundation in collaboration with the Institute of Reconfigurable & Embedded Digital Systems (REDS) of the Haute Ecole d’Ingénierie et de Gestion du Canton de Vaud – HEIG-VD in Switzerland. The activity is part of the ARTES programme of the European Space Agency that supports innovation in satellite communications.
SDRmakerspace brings together makers, open-source hackers, radio amateurs, and researchers providing funding, resources and a passionate community tackling together challenges in using Software Defined Radio for space communications. By doing so, it is opening up development to a wide variety of people, organizations, and companies.
We will present the final results of the subactivities undertook within SDRmakerspace in three 2-hour slots (for which you are requested to register separately) in the afternoon at 15:00 CEST (13:00 UTC) on Mon 6, Tue 7 and Wed 8 September 2021.
The event is organized by the European Space Agency, and will be contacted using the Webex platform, it is open to all interested individuals provided they register through Eventbrite in the provided links below.
Monday 6 Sep will be focused on the evaluation of various SDR boards and FPGA tools chains. High-rate direct sampling by SDR’s and SDR on Android will also be presented.
Tuesday 7 Sep will be dedicated to building blocks that have been implemented as open-source developments for GNURadio, such as gr-leo, gr-ccsds, gr-soapy etc.
Wednesday 8 Sep is mainly about the combination of SDR and AI/ML to do signal detection and classification. In addition, an SDR test-bed and spectrum monitoring will be presented.
Firefly Aerospace a few days ago announced the successful static fire test of the Firefly Alpha launch vehicle on its launchpad, preparing for its inaugural flight. On the final stage of this rocket, Firefly Aerospace engineers have integrated PicoBus, Libre Space Foundation’s open-source hardware PocketQube class satellite deployer, hosting several satellites including Qubik 1 and Qubik 2.
The Qubik twins as soon as they will be deployed in orbit will perform radio amateur experiments investigating various modulation schemes for performance and orbit determination.
As we get ready for this launch, Zach’s PaperSat Designs has created a paper model of the Qubik satellite.
Don’t hesitate to build your own. You will just need a couple of sheets of 65lb card stock paper (160gr/m2 might also work for you), glue, a colored printer and download the following PDF files for the paper model and instructions.
We recommend checking out all of Zach’s PaperSat Designs models, including UPSat, the previous open-source satellite mission Libre Space Foundation re-designed, integrated and delivered (PDFs of the model and instructions).
In the past two weeks, we focused on the projects that Libre Space Foundation has been mentoring in this year’s GSoC programme. Thus, we have already presented the project about Improving the transmission capabilities of gr-satnogs by Michalis Raptakis and Expanding events detection in Poliastro by Yash Gondhalekar. Today, we will focus on Rich Analysis Reports for Polaris by Ayush Bansal.
Polaris ML: An Introduction
Polaris ML is an open-source, python-based, machine-learning tool aimed at helping satellite operators detect spacecraft behaviour. It is a solution developed to facilitate space diagnostics. This is achieved by helping spacecraft operators investigate anomalies. Polaris ML explores and analyses satellite telemetry data and delivers helpful graph visualisations. These visualisations are machine-learning models illustrating the dependencies of the telemetry parameters.
*The project is under active development, and the team will be implementing more changes in the future.
Polaris ML and GSoC
For Polaris, this is the third year that the project participates in the Google Summer of Code. This programme has benefitted Polaris ML massively, as it has brought the project in liaison with excellent students that have helped it evolve greatly. Talented, past participants of the GSoC programme are now integral members of the team developing Polaris ML. This year, the project has welcomed Ayush Bansal, an Electronics and Communications Engineer student at the Indian Institute of Technology, Roorkee in Rajasthan, India.
Rich Analysis Reports for Polaris
During his GSoC internship, Ayush has been working on developing two new module commands. These are polaris behave and polaris report.
- polaris behave. This module uses a pre-built autoencoder model from the BETSI library to detect anomalies in satellite telemetry data. The results found will be delivered in an easy-to-read, exploitable format.
- polaris report. The second module that Ayush has been working on aims to use the results from polaris behave and portray them in an interactive way in a web browser for the users to comprehend, interpret, and read more easily. The visual module will use the results of the anomaly detector and other raw data to produce a graph. A local, browser-based webserver will be created to serve interactive graphs. The graphs will be presenting the different anomalies, their points of occurrence in frames and the different parameters.
As Ayush describes the GSoC experience with Polaris..” We planned stuff, fixed bugs. [D]id some sword fights over topics and Merge Requests and Issue Filing became [a] regular thing for me.
I learnt [the] importance of how to code properly, give proper names to different functions, explain the aims of the code more clearly and a lot more.”.
You can have a closer look at the Merge Requests that Ayush has worked on here.
What is next?
As Polaris ML is a project under active development, a series of interesting updates are coming up. In the next months, the team will be working on many improvements optimising the tool even further. As far as web reports are concerned, supporting multiple satellites by URL separation, improving the responsiveness of the reports themselves, using Graph Comparison to collect all the information responsible for an anomaly are some of the features that the team will be working on.
A PDF generator is to be developed, too. It will be customisable to the user’s needs as they will be able to choose which parameters will be included in the PDF. For instance, they will be able to customise the time period and the number of anomalies detected. Ayush will also be developing a feature that will allow the users to combine all the graphs in a bundle and deliver them in a zip file for further use of the results found. Lastly, a command-line option will be explored to be able to trigger the reports easily.
Want to join the community?
If Polaris ML sounds fascinating to you and you want to join the team, you can reach them at the dedicated Polaris matrix/element channel. You are welcome to sign up and contribute to the project and the discussions taking place there. The Polaris team is made up of talented individuals from around the world, and the community is open to everyone interested in space, machine learning, and open-source technology. As Ayush describes it in his article..”I didn’t know much about space telemetry and satellites, so I learned a lot from the community…
..Despite these people’s various engagements, they were responsive, which helped me get my doubts cleared as soon as possible.
It was a great summer working on this project….[this was] More than an Internship. “
*You can follow Ayush’s personal blog and read about his journey as a Web developer here.
Supporting knowledge and scientific research are among our main goals at Libre Space Foundation. This is why we have been participating in the Google Summer of Code for the third year in a row, mentoring three amazing projects. The first project is about Improving the transmission capabilities of gr-satnogs developed by Michalis Raptakis. We presented this project in more detail last week. This week, we are delving into Poliastro.
Poliastro and GSoC
In 2021 Poliastro is participating in the Google Summer of Code programme via Libre Space Foundation. Yash Gondhalekar, a Computer Science student at the Birla Institute of Technology and Science in Pilani, India, is spending the summer working on the project. Tinkering with the code to achieve a streamlined execution of algorithms, adding event detection capabilities and improving the tool.
Poliastro: An Introduction
Poliastro is a pure Python library that provides an API tackling issues of astrodynamics and orbital mechanics. Its goal is to benefit users by providing valuable scientific information. This information will contribute towards creating more effective space strategies, improved orbital designs and more efficient maintenance policies.
The software for this tool is under constant improvement and development. Thus updates are to be released regularly.
Poliastro: A closer look
Events detection is a challenging process. Upon embarking on the GSoC experience, the Poliastro team began focusing on the eclipse detector, which appeared to be a more challenging task to tackle. After brainstorming over the most suitable method to handle this, the team decided to opt for SciPy’s event support.
Though SciPy did offer a solution to approach the issues, the team “.. still needed to come up with a time-varying and continuous “shadow” function without having to solve analytical equations manually .”
For this to be achieved, an equation had to be formulated.
After a series of geometric manipulation tests, an equation was created comprised of classical orbital elements. But the team did not stop working on the solution. As Yash points out, ” We were still questioning the performance and complexity of the method since by enacting it, we could lose the accuracy of entry and exit times of the event. In any case, the other (methods) didn’t seem to work just yet, so we decided to go with this approach since it looked feasible.”
At the same time, the team also worked on the altitude and latitude crossing detectors. However, soon enough, they realised that there are far more intricacies in the longitude detector. This required more thinking and more exploration to find the right approach and method to deal with the issue. ” All the events are supposed to work for any attractor, thus aligning with one of (the )Poliastro’s aims of having capabilities not restricted to (the )Earth.”
By leveraging some of the in-built functionalities of solve-ivp, users can stop the integration when an event is detected or control the direction of triggering an event. With the development of validation cases for the Orekit software, the team enhanced the possibility of further implementation; the tool was optimised even more by adding tests, fixing bugs and improving computation.
You can read how the team went about approaching all the issues arising in Yash’s detailed article.
Want to join the team?
As is the case with all the project communities at Libre Space Foundation, the Poliastro team is an open and inclusive community welcoming members from all over the world. In his first article about the GSoC experience with Poliastro, Yash states, “Needless to say, this is a place where I would get to interact with an engaging community and learn several things”.
If this sounds like an interesting project to you and you want to be part of this team, you can join the dedicated Poliastro channel on element/matrix and contribute to the discussions there.
The next steps
Yash and the team are working hard on further optimising Poliastro, and in the weeks to come, more event detectors will be included!
*You can follow the updates of the Poliastro project here.
At Libre Space Foundation, we are dedicated to developing and supporting open-source space technology and projects that promote knowledge and improve space operations. Polaris is a project developed with the support of Libre Space Foundation (LSF). It brings together developers, engineers and university students from around the world. A diverse group of people with a shared interest in space and open-source technology. They are the ones working hard on designing, developing and optimising Polaris: a Python-based, Μachine-Learning (ML) tool, developed in an open-source, collaborative way, aimed at applying machine learning to satellite telemetry.
Polaris ML for SpaceOps
The challenge: Satellite operators, during a mission, have to tackle a daunting yet critical task; to monitor and keep track of numerous telemetry parameters to maintain a clear idea of the behaviour of their satellite. They need to comprehend how these parameters interfere with each other and estimate their impact accurately.
The Solution: This is where Polaris ML gets into the picture. It is a command-line based, machine-learning tool providing a satellite-telemetry analysis that can be of great help to satellite operators. The data collected are turned into comprehensive graph visualisations, using machine-learning models to understand and predict a satellite’s behaviour. Other data sources are also converted into valuable information available to spacecraft operators.
Note: Before examining Polaris ML in more detail, allow us to describe briefly how satellite operators handle these issues at the moment. Though satellites are built to be more self-aware nowadays, operators are still required to jump in and evaluate the situation by setting manual limits. This is called the Out-Of-Limit (OOL) technique which analyses and evaluates the behaviour of a satellite by collecting data and raising out-of-limit alarms about the state of a satellite. Consequently, a ‘soft out-of-limit’ alarm indicates a dangerous trend, while a ‘hard out-of-limit’ alarm is indicative of a failure occurring. At this point, let us clarify that Polaris ML does not seek to replace operators or the techniques already applied. Instead, what Polaris ML is after is to be able to provide assistance and amplify the process. Polaris ML is after becoming a reliable, efficient and complementary solution for Space Operators.
A closer look
Before analysing the project, let us point out that this is a tool under active development, thus, the interface is very likely to change. Allow us now to delve into the different components of Polaris ML.
Polaris ML makes use of the XGBoost algorithm to analyse the relationship and the inter-dependencies between telemetry parameters. The XGBoost library allows for eXtreme gradient boosting. This is an approach enabling new, updated, and better-informed models to be created by predicting the errors of the previous models. Then, both models are added together to deliver a final prediction. Using this approach, Polaris ML predicts every telemetry parameter in a satellite. It then provides a graph illustrating the interdependence between the parameters, depicting the degree to which one parameter affects the other. The importance of telemetry parameters and how these are linked is presented as a web-based, 3D-interface graph. 3d-force-graph is the component used for the graph output.
Polaris ML is made up of these distinct parts:
- polaris fetch: As the name reveals, this part fetches the data from various sources. Including telemetry data from the SatNOGS Network and Space Weather from SWPC (NOAA).
- polaris learn: This part consists of a machine-learning (XGBoost)-based module that analyses the relationship of all the “fetched” data and returns a JSON graph file as the output.
- polaris viz: A 3d graph-based visualisation module providing an intuitive graph representation of the data.
- polaris convert: A tool used to convert graph outputs from “polaris learn” and “polaris viz” into other formats. For now, it only supports the .gexf formats, which is a language utilised for describing complex networks structures, as well as the associated data and their dynamics.
Vinvelivaanilai is a Python module that fetches space weather data from servers of SWPC/NOAA. It then stores the data in text files or on the InfluxDB. It also includes functions enabling TLE and OMM parsing (any GP data) and propagating the orbit of a satellite to locate both its position and its velocity at any given time.
Vinvelivaanilai is the word for space weather in Tamil.
The word BETSI stands for “Behaviour Extraction for Time-Series Investigation”, and it aims to implement a state-of-the-art model to detect anomalies automatically without any manual intervention. The model for creating the concise representation is called autoencoder, and it utilises deep-learning techniques to detect any anomalies found within the telemetry data.
But what exactly is an anomaly?
Anomalies are all events that fall outside the spectrum of the nominal behaviour of a system, generating massive shifts in the values of one or more parameters. Anomalies can have a catastrophic impact on the satellite, especially since their spectrum is quite broad, as it may range from a simple change in orientation to a massive explosion. (One can only imagine the impact).
Polaris ML in a nutshell
Polaris is an open-source, python-based solution developed to facilitate space diagnostics and help spacecraft operators investigate anomalies. It aims to support and enhance satellite operators to improve their processes by enabling them to detect spacecraft behaviour and helping them drive their investigations when anomalies occur.
Valuable Resources on how to get started and join
As we plan to take this project to a broader scale and see it developing further and expanding, we have created a list of resources that can help you familiarise yourself with Polaris ML. To start with, these are the Polaris repositories on GitLab. Then, you can check the detailed documentation that is available online as it walks users through the Polaris ML project. There are also several exciting talks and presentations by some of the members of the Project.
- “What the hell was that?-Satellite Behaviour Analysis with machine learning” by Xabier Crespo Alvarez (Open-Source CubeSat Workshop 2020) https://www.youtube.com/watch?v=SxYeLhbY2lU
- “Polaris: Open Source Machine Learning for Spacecraft Operations” by Hugh Brown (PyCascades 2021) https://www.youtube.com/watch?v=0jNMDqTqD2s
- “Polaris: Open Source Deep Learning for Telemetry Behavior and Anomaly Detection” by Redouane Boumghar (CubeSat Developers Workshop 2021) https://www.youtube.com/watch?v=VUeVt8-DFkc
Want to join the community? Find out how you can get in touch with the team
Polaris ML is backed up by a diverse, international team, welcoming people from different continents, cultures and backgrounds. The project is developed in a collaborative, open-source way and is fostered by an inclusive community. If you want to join, you can contact the team at the dedicated Polaris ML element/matrix channel: https://app.element.io/#/room/#polaris:matrix.org. You are welcome to join the channel, introduce yourself and contribute to the discussions there.
Polaris ML and GSoC
The Polaris ML team welcomes students from all over the world, and it is a popular project sought after by students applying for the Google Summer of Code program. Polaris ML participates in the programme for the third year in a row. The entire team has had great experiences with GSoC, and the project itself has expanded due to the support and contribution of the GSoC students. Adithya Venkateswaran, who has created the Vinvelivaanilai library, has been a star student of GSoC and is an integral member of the Polaris team.
Polaris ML is an aspiring project with great potential; it aims to optimise space diagnostics, reduce operation workload and enhance autonomous spacecraft operations. With the help of machine learning, Polaris ML aims at becoming a reliable, scalable solution for Space Operations. The project is still developing, optimised to deliver even better intuitive graph models, creating valuable and dynamic anomaly reports. Polaris ML is after opportunities to implement and test this solution in future satellite operations. We have already worked with BOBCAT-1 and the QUBIK pair of satellites. Still, as we wish to improve further and expand, collaborations with satellite operators for upcoming missions are welcome. Especially since we want to test further and optimise the solution itself and its key components.
The Library Space Technology Network (LSTN) is a project brought to life by Wolbach Library in collaboration with Libre Space Foundation. LSTN is a pilot program aimed at offering public library communities the opportunity to engage with Space Technology. Though the project is ambitious, language poses substantial limitations for communities to join. And this is where we need your help!
The LSTN project: a more detailed look
The goal of LSTN is to broaden participation in space-based science and engineering, through novel educational opportunities and hands-on learning experiences with open satellite technology in public libraries. It achieves that by giving communities a SatNOGS ground station and educational resources to support their use. At the moment, there are 5 public libraries around the world participating in this initiative: Public Library “B.P. Hasdeu”, in Chișinău, Moldova, Public Library of Santiago, Chile, Cambridge Public Library in Cambridge, MA, USA, John G. Wolbach Library in Cambridge, MA, USA and Marathon Public Library in Marathon, TX, USA.
LSTN is a project with great significance and potential; capable of expanding and including more libraries worldwide. LSTN can grant people access to a set of shared resources that can open doors, provide novel learning experiences, and inspire lifelong learning. Especially, in communities where opportunities to connect with space-based science are limited.
The LSTN Handbook
For libraries to be able to install a SatNOGS ground station, there are several valuable resources available, including a Handbook. The latter provides a detailed walkthrough and guidelines for the entire process in English. And this is where your help is required to get this project to the next stage! As language can be an insurmountable barrier, the LSTN Handbook needs to be translated into more languages to help spread knowledge and space technology to more communities worldwide. For this, we would like your help in translating it into Spanish and Romanian. These two languages are of a high priority now, however, you can add more languages and help us with those translations too!
The Handbook Translation is powered by Weblate, and a tutorial has been created to make the process easier for you. In addition, there is a Weblate Glossary to help you understand the terms Weblate uses. For any questions you might have you can use the LSF community forum, the dedicated MetaSat element/matrix channel, or email the team at email@example.com.
Update: The Progress so far
In the last couple of months, the project has attracted the attention of many volunteers that dedicated their time and effort to translating the Handbook into more languages. New languages have been added and progress is made slowly yet steadily. At the moment, the Handbook is being translated into 14 languages and 30.2% of the translations are completed. This is why your contribution is still very much needed to make this project accessible to more communities and make space available to the public.
At LSF, we are devoted to promoting knowledge and finding ways to introduce and include more individuals, teams and communities in space technology development and exploration. We are excited to be working with the Wolbach Library on LSTN to include and engage more communities. However, we need your help to break linguistic barriers and make the LSTN Handbook accessible to many languages. So if you are a space enthusiast, a supporter of knowledge, and want to contribute to take this project globally, you are welcome to begin working on a translation. Do not hesitate to share this article with someone who might find it useful or is willing to help!
For the third year in a row, Libre Space Foundation is selected as a mentoring organisation for the Google Summer of Code program. The application period has now closed and the results are in!
The three projects that will be participating in this iteration of the Google Summer of Code via Libre Space Foundation are the following. Let us check them out:
Expanding events detection in Poliastro
Poliastro is an open-source, python library for interactive astrodynamics and orbital mechanics. This project will work on expanding the event-detection capabilities of Poliastro. It plans on achieving that by adding several event-detection algorithms and methods to it. These detectors will allow Poliastro to calculate eclipses, collisions, line-of-sight, sunlight exposure, altitude thresholds, longitude/latitude crossing, visibility of orbiting objects from a location on earth, and sunrise/sunset and moonrise/moonset times also from a location on earth.
Rich analysis reports for Polaris
Polaris is an open-source tool that applies machine learning to satellite telemetry. This year’s project will create a visual module for Polaris. This will use the results of its anomaly detector to generate web-based interactive graphs, visualising anomalies and their points of occurrence. At the same time, it will allow pdf generation and command-line tools for these.
Improving the transmission capabilities of gr-satnogs
Gr-satnogs is the GNU-Radio, Out-of-tree module used by the SatNOGS open-source satellite ground-station network. The scope of this project is to expand the current transmission capabilities of gr-satnogs. This has already been tested on UPSat while in orbit and on Qubik 1 and Qubik-2 in the lab. To achieve that the project aims to improve the gr-satnogs transmission framing API and add new encoders to the already existing AX.25 and IEEE 802.15.4 such as the Nanocom AX.100, various AMSAT-related encoders and more.
Google Summer of Code is an annual program offering university students the opportunity to work on open-source projects during their summer break while earning a stipend! Libre Space Foundation is devoted to working on open-source space technologies and you can find out more about our Principles regarding open-source and space in our Manifesto.
This year’s Google Summer of Code application received 6991 applications submitted by 4975 students from 103 countries. These applications were reviewed by 199 mentoring organizations. Eventually, 1292 students from 69 countries were selected.
We are thrilled to be part of this grand initiative. But we are also excited and looking forward to working with our students over the next few months. Congratulations to everyone and welcome aboard!
The 2021 CubeSat Developers Workshop is happening in a few days and is organised by Cal Poly, San Luis Obispo, CA, USA. It will be a virtual conference taking place from the 27th to the 29th of April. The CubeSat Developers Workshop (#CubeSatDW) “Working Together” will feature amazing talks and useful workshops. You can find the full schedule of the event here.
To start with, the event this year features a mix of pre-recorded and live sessions and the registration is free for both. For the Keynote Addresses and the Live Q&A Panels, a passcode will be forwarded to you via email, after the registration. By using that passcode, you will be able to join the live discussions. On April 27th, the pre-recorded presentations from the Live Q&A panellists will be released. This will allow for the registrants to view the presentations and prepare the questions before the live Q&A panels. During the event, there will be time available for the attendees to network.
Libre Space Foundation’s strong presence at the 2021 CubeSat Developers Workshop
At Libre Space Foundation we are thrilled to join this year’s CubeSat Developers Workshop with a number of fascinating and significant presentations from many of our projects. No day of the event will pass without a presentation from a Libre Space Foundation project. With Day #1 featuring two projects of ours. Let us take a more detailed look at the Libre Space Foundation presentations and our speakers:
On Tuesday the 27th of April, Day #1 of the event there are two LSF-related presentations:
- “I hunt satellites”: crowdsourced satellite telemetry collection with SatNOGS
by Corey Shields | Libre Space Foundation
- “MetaSat: An Open Metadata Toolkit for SmallSat Missions”
by Daina Bouquin | Harvard-Smithsonian Center for Astrophysics
- “Polaris: open-source deep learning for telemetry behavior and anomaly detection”
by Red Boumghar | Libre Space Foundation
And on Thursday the 29th of April, Day #3 of the Event:
- “SatNOGS – COMMS: Turnkey Nanosatellite Communications”
by Manolis Surligas | Libre Space Foundation
We are very excited and looking forward to enjoying all the presentations featuring at the event.
Save the dates and join us at the 2021 CubeSat Developers Workshop virtual conference.
See you online!
Google announced today that Libre Space Foundation is among the mentoring organizations of Google’s Summer of Code 2021.
This selection provides opportunities for students that would like to work on open-source space technologies during their summer break and start participating in the Libre Space community.
If you are an eligible student and interested in working with open-source space technologies this summer, don’t hesitate to study the student guide thoroughly, and check our detailed instructions, with suggested ideas, or introduce your ideas for consideration.
To get a taste (and inspiration) of the work of last year’s mentees check the reports of their contributions to Deep Learning and Space Weather for satellite data and a python library to detect RF collisions in SatNOGS.
The Open Source CubeSat Workshop 2020!
The Open Source CubeSat Workshop is a yearly event that brings together enthusiasts from the fields of space technology, engineering, CubeSats, mission control and analysis, and of course, Open Source. The event has been around for four years and has been gaining continuous success and building rapport among Space and Open Source Technology supporters. In an attempt to maintain stability in a rather unpredictable year when a pandemic has been sweeping the globe, the event was decided to take place online. We found no better way to guarantee the safety of attendees and speakers alike, than participating in an online event from the comfort and safety of our home. And that brought on the Open Source CubeSat Workshop 2020 – online edition; with a strong focus on sharing ideas and promoting collaboration; even when confined at home on different meridians of the planet.
On the 12th and 13th of December, the Open Source CubeSat Workshop 2020 kicked off online! The event was streamed live on the Libre Space Foundation YouTube Channel and it brought together people from different continents, backgrounds and disciplines. At the same time conversations and insightful discussions were taking place on the YouTube Chat and on dedicated matrix channels (via element.io), where information provided by speakers (tips/source code/awesome list) was also shared. A community buzzing of ideas for cooperation that you can join any time of the year and explore collaboration potentials.
The event featured two Rooms where presentations took place in parallel; fascinating lightning talks and detailed tutorials. Overall there were 20 presentations, 12 lightning talks and 5 tutorials and here is the playlist with all the videos from the event.
The Open Source CubeSat Workshop 2020 was a fun and informative event where knowledge and great ideas were shared openly. Fascinating discussions and Q&As provided insightful approaches and there were some interesting conclusions.
Key take away
OSCW is a great occasion, every year, to realize the immense impact of the open-source projects that compose the space industry, by playing an important role in enabling access to key technologies for creating and supporting space missions. Every year we see gaps being filled like the DOCKS software suite, managed by Observatoire de Paris (CCERES), offering a complete set of tools for space mission profiling. Thanks to the feedback provided by the community, the project has been restructured, to feature an easier interface and understanding of its different tools. SatNOGS project, the Satellite Network of Ground Stations, is realized by volunteers across the globe and it continues to expand. Coverage expansion, the well-scaling infrastructure and its evolution were presented while the project maintains user-friendly interfaces for flight control teams to store, access and view their spacecraft telemetry. SatNOGS puts the finger on key challenges (satellite detection, identification and tracking, easy deployment of SDR-based ground stations, and ground infrastructure). OpenSatCom was also presented at the event. This is an activity of the European Space Agency managed by the Libre Space Foundation; the latter has recently produced a resourceful report about Open Source, development methodology models for satellite communications.
The workshop also featured a lot of tutorials and information about the things you need to know if you are into creating your own smallsat mission or managing an existing one. It included everything from open-source embedded software and implementation of ECSS standards to the latest update on how to propagate an orbit and why you have to say goodbye to TLEs; as well as how to use machine learning to analyze your operations data.
There were plenty of other key projects presented like MetaSat or the standardization of PC/104 connectors with the Librecube initiative that you can retrieve from the contributions list.
OSCW is also the siege of numerous shared ideas as all interventions do trigger one’s imagination. Lightning talks provide great inspiration. They are the perfect example of how you can quickly get a team of contributors for a project like a ground station in a backpack. Or they can inspire the birth of an idea which was not even on the initial list and it was formed on the spot. By raising the interest of the attendees during a talk, you get to inspire people who wish to contribute to your project. It is because of this that often you can find somebody saying “I’ve got something I can share with you and we can make it”; such as the air-bearing testing equipment for testing your ADCS (during the astonishing liquid metal-based pico reaction “wheels”).
Though this year the event was different, as it went fully online, it was indeed a successful one! As it did manage to gather an online community of enthusiasts who are dedicated to Open Source, Technology and Space. It managed to overcome boundaries and a pandemic and to allow individuals from around the globe to unite under their shared interest. For this, we would like to thank everyone! The attendees for forming a friendly community of great diversity and knowledge, the speakers and presenters for creating great interactions and sharing insights, the contributors for enabling a smooth experience and the OSCW committee for putting everything together and overseeing the event. We would also like to thank the teams behind Indico (our conference management tool), The Big Blue Button (amazingly smooth video conferencing, with multi-user whiteboarding and break sessions), Element.io and Matrix for powering the conversations, links & file-sharing of this year’s iteration of The Open Source CubeSat Workshop 2020!
Until we meet again, next year and hopefully in person, feel free to enjoy the recordings of this year’s event and go through the presentations and talks. They are a great source of knowledge and you can shuffle through them and acquire great insight.
In the meantime, stay safe and connected!
Libre Space Foundation (LSF) is devoted to designing and building open-source space technologies. We always support and promote space exploration, scientific research and knowledge. For the past year, we have been working hard on the QUBIK mission to create a platform on which a series of amateur radio experiments will be conducted, upon the mission’s launch.
Ιn a nutshell
For the QUBIK project, Libre Space Foundation has designed and developed two open-source PocketQube Satellites, QUBIK-1 and QUBIK-2. As part of the QUBIK mission, LSF has also designed and built PicoBus; the first, open-source PocketQube deployer. The QUBIK PocketQubes along with AMSAT-EA‘s GENESIS-L and GENESIS-N and Fossa Systems‘ FOSSASAT-1 and FOSSAT-2 were integrated into the deployer and are part of the Firefly Aerospace’s DREAM payloads program on its inaugural Firefly Alpha launch.
The Story so far
Over the past year, the PicoBus, as well as QUBIK-1 and QUBIK-2, underwent all the necessary, standard testing and verification campaigns.
For example, by the first months of 2020, PicoBus had undergone the thermal vacuum test and the vibration test. From there, it was time for assembling the PocketQubes and the deployer, and then the bake out was in order. Shortly after, the Acceptance campaign took place for PicoBus, and so did the Protoflight Campaign for QUBIK-1 and QUBIK-2. You can read more about the extensive testing and the processes that took place earlier in the year here.
While the hardware was undergoing all the testing, the software was polished and tested too, aiming at enabling a series of fascinating amateur radio experiments.
The two PocketQubes, QUBIK-1 and QUBIK-2 are designed to have a short life span of 3-4 weeks. Though this period of time is relatively short, it is enough for LSF to run a series of amateur radio experiments. These are primarily scheduled to take place during the Launch and Early Orbit Phase (LEOP) of the operations and the amateur radio experiments revolve around satellite identification and tracking. LEOP is a critical phase for satellites and spacecraft operations; since the sooner a team identifies and picks up communication with the satellite, the better it is for the entire operation. Identifying and tracking a satellite early on, almost upon deployment, helps the team to proceed fast and tackle possible problems arising. It is the significance of early identification and tracking and the impact this has on saving missions and operations that prompted LSF to decide to focus the scheduled experiments on that specific Phase of operations. By forming a series of assumptions about Satellite identification and tracking, LSF has set the objectives for experiments that need to be conducted in search of possible solutions.
Thus, QUBIK-1 and QUBIK-2 will set out to help explore the following objectives:
- To unambiguously identify satellites as soon as possible after deployment
As we mentioned above, early satellite identification and tracking are of primary importance as they allow the operations team to act fast and address possible issues early on. Be it communications or altitude-related issues they should be dealt with swiftly, especially since failure to do so promptly, might render an operation unsuccessful. QUBIK-1 and QUBIK-2 are designed to enable easy RF Identification during the LEO Phase.
- Generate or update existing orbital elements based on Doppler curve tracking of satellite transmissions
The process of identification and tracking becomes even more complicated. As is often the case, nanosatellites and microsatellites are deployed in numbers, many together, from the same launch vehicle and flying in the same orbit. Distinguishing between them and tracking is a daunting task, puzzling the teams as the operators of these satellites often rely only on external tracking alone. They rely on the only available public resource providing orbital elements, and that is the Combined Space Operations Center (CSpOC) (through their space-track.org dissemination website.) Nevertheless, things get even more perplexed for operators as in addition to crowded deployments the small radar cross-section makes identification via CSpOC quite a challenge. Both of these parameters are the cause of significant delays in the publishing of the initial orbital elements. It can take up to a few weeks to identify a satellite accurately, and sometimes they might not be identified at all.
For dealing with the issues of misidentification and no-identification at all, for the QUBIK PocketQubes passive Doppler tracking will be utilised. This will be facilitated through SatNOGS (the global network of satellite ground stations) in order to independently determine orbital elements during the Launch and Early Orbit Phase.
- Extensively explore objectives 1 and 2 and do so in a way that adheres to the Principles of the Libre Space Manifesto.
All LSF’s operations and projects are led forward by the Principles of the Libre Space Manifesto, which constitutes the operational framework of all LSF processes. This means that the objectives mentioned above will be explored accordingly; in a scalable and open-source way with the data collected being distributed openly for everyone to have access.
- Create a reusable, open-source PocketQube Platform.
At LSF, we have been focusing our attention on the PocketQube format, and for this, we have worked hard to build a reusable, open-source ProcketQube Platform with a complete stack of open-source technologies developed for it. This is because we see potential in the PocketQube format as it is versatile enough and low-cost, able to facilitate a wide variety of amateur radio experiments, payloads and to have a wide range of technology developed around it.
QUBIK-1 and QUBIK-2 will be used for testing, aiming at exploring the aforementioned objectives to the fullest. These will be investigated in-depth through a series of amateur radio experiments regarding the Identification and Tracking of Satellites.
This part of the amateur radio experiments focuses on radio beacons and Telemetry transmissions, and they include:
Digital modulation schemes may use a preamble or a postamble in order to provide narrow-band transmissions which can help facilitate tracking from RF spectra. Distinguishing between satellites can be achieved by estimating the differences in preamble/postamble length. However, since preambles in most framing schemes are often the same, this constitutes preamble not an ideal solution to allow unambiguous identification.
By demodulating and then decoding the signals captured, this approach allows for identification via a call-sign or address within the packets. It requires full demodulation and decoding data chain. The assumptions required about SNR, RX sensitivity and RF collisions on narrow, non-spread-spectrum modulations will only compromise demodulation and decoding.
Note that this is one of the amateur radio experiments that LSF will be running as this does not require any changes to be made in the existing workflow. Thus, it will be introduced in QUBIK as a control case (since the team already utilizes it).
Identifying a satellite by estimating the differences in beacon length. In crowded deployments, as is the case of QUBIK-1 and QUBIK-2, this is not a scalable option.
Differences in beacon cadence can also help distinguish between satellites, by estimating how often a beacon is transmitted. Though this approach helps prevent beacons and satellites from overlapping it can not be applied in crowded operations.
Barker codes can be utilised to provide monotonic identification right from the RF level by performing only cross-correlation at the raw signal. Barker codes require only bit-level changes, and they can be used to facilitate lower SNR identification and decoding, identifying a spacecraft right from the PHY. However, for this approach to work, it would require ground stations to have multiple decoders operating in parallel. As the number of the decoders would have to be possibly equal to the number of different code sequences, this approach is not scalable for us to pursue.
Spread spectrum low power beacon
For this amateur radio experiment, the RILDOS proposed protocol was chosen, transmitting a beacon with low transmission power. The basic idea which we will explore is to use the spread sequences of the RILDOS protocol and retrieve a message from a satellite even in a negative SNR environment. What is more, with this amateur radio experiment LSF will attempt exploring possible techniques that can be applied on an SDR-based ground station estimating the frequency drift between the spacecraft and the ground station. The techniques applied will be estimated and evaluated on the grounds of their accuracy and whether the RILDOS protocol can be used for both identification and tracking.
Keep in mind that even though RILDOS requires 2 Mbps, in this experiment and due to hardware restrictions, RILDOS will be tested in lower bandwidth. In this case, the basic features of the protocol will remain intact while the performance in terms of BER is expected to be affected and possibly degraded.
This too will be one of the amateur radio experiments that are scheduled to be conducted in QUBIK-1 and QUBIK-2.
The tracking of the QUBIK PocketQubes through their Doppler curves must be achieved by measuring transmitter frequency as a function of time. This can be determined directly either from waterfalls, the artifacts provided by the observations made by the SatNOGS Network or by demodulating transmissions. Tracking waterfalls does work well for lower signal strengths, but when it comes to digital modulation schemes, it gets harder to obtain the transmitter frequency. This becomes difficult when transmissions of satellites overlap.
Waterfalls can facilitate satellite tracking for any modulation scheme with narrow-band features. CW would provide the highest accuracy at the expense of low bit rates.
By using a preamble or a postamble, digital modulation schemes can provide narrow-band features in the waterfalls. Examples of this approach are the BPSK transmissions of Funcube satellites or the FSK transmissions like those of UWE-4 or Firebird-4.
The residual carrier is a strong carrier found on top of the modulation spectrum mask as it runs for the entire frame duration. Usually, the residual carrier is utilised to drive the PLL that tracks any frequency drift that can be retrieved either from the RF level or visually.
Since the RF IC of QUBIK (AX5043) does not support an optional residual carrier, LSF will opt for an alternative yet innovative approach. By using QPSK with special precoding, it can be forced to use only two of the QPSK symbols. This produces a DC biased BPSK, which eventually will have a carrier at the center of the spectrum mask. What makes this approach possible is the absence of a DC block filter on AX5043.
If you want to have a look at the amateur radio experiments in more detail, you can read the documentation.
The latest Updates: Final QUBIK-1 and QUBIK-2 Testing and PICOBUS Integration
The QUBIK team has been developing and testing the software throughout the summer, updating and implementing features; following strict procedures so that the QUBIK project to be ready for the final testing and integration. The last weekend of October 2020, was an exciting one, for us at Libre Space Foundation because not only did the final testing of the PocketQubes take place but also because of the integration of the PocketQubes in the PicoBus deployer.
Both procedures took place at the LSF Headquarters, at hackerspace.gr, in the centre of Athens, Greece and were carefully orchestrated and successfully carried out while being streamed live on the LSF YouTube Channel.
The PicoBus Deployer with the six integrated PocketQubes will be shipped to the US.
Firefly’s Aerospace Alpha launch is expected to happen as early as Dec. 22 with room in the schedule to launch as late as Jan. 31.
For us, at Libre Space Foundation, the QUBIK is an aspiring project of which we are immensely proud. It is a self-funded initiative to create an ideal environment for testing and conducting amateur radio experiments. All the technology stacks used and the tools created are open-source. The solutions to be found (if any) will further enhance and enable a wide variety of amateur radio experiments, payloads, technology development and missions.
All these are governed by and conform to the Libre Space Manifesto, and its Principles found etched on the QUBIK PocketQubes.
We are proud to announce that Libre Space Foundation has been accepted as a member of the International Astronautical Federation! We are excited to be part of such a great community with which we share a love for Space, Space exploration and research.
International Astronautical Federation and Libre Space Foundation
IAF aims at “Connecting @ll Space People” bringing together organisations, universities, space agencies, research institutions and individuals with a profound interest in space. It has managed to successfully build a community, A space-faring world cooperating for the benefit of humanity. It does so through establishing collaborations and partnerships, by creating events and educating the public so that scientific knowledge and information are shared and spread for everyone to acquire. Libre Space Foundation works hard towards bringing space exploration closer to the public, enabling research and supporting education through all of its projects. We believe that Space is humanity’s future and that space should be accessible to all. This is why we support openness in space tech development and data distribution so that knowledge about Space technology and information about space exploration can fuel a better future for all. We both perceive Space as a great opportunity for growth and development but only when it is used to promote peace, knowledge and scientific research. When it is open to everyone to learn and explore freely. We firmly believe that the only way to explore Space to its fullest potential and to benefit humanity is through partnerships and collaborations with shared ideals and dreams. This is why we are very excited to have joined IAF.
A few words about the International Astronautical Federation (IAF)
IAF was founded in 1951 and it is the world’s leading space advocacy body. It counts over 397 members in 69 countries worldwide. Among its members, there are leading space agencies, Universities, companies, research institutions and even museums.
IAF encourages the development of astronautics for peaceful purposes and supports the spreading of knowledge and information about space. It is also the organiser of many thematic events promoting scientific research and knowledge, and it is the organiser of the International Astronautical Congress (IAC) – a significant annual event about space. 2021, marks IAF’s 70th Anniversary. You can read more about IAF’s long history of supporting space and knowledge by reading its History Page.
The International Astronautical Federation has always supported Space, Space exploration and making technical and scientific knowledge available to those interested. Its vision is powerful and its missions are noteworthy and not limited to one field.
- Promoting Cooperation. By organising events and committees it brings experts from all over the world together to collaborate on research and to deal with the issues the industry faces.
- Advancing International Development. Through collaboration between nations, companies, institutions from all over the world.
- Sharing Knowledge. The information collected and the knowledge acquired is shared using many well-established channels.
- Recognizing Achievements. Not only does it keep an eye on the developments regarding space but it also presents awards to the individuals and groups which help move the global space community forward. Each year the IAF awards are amongst the most prestigious awards to be given.
- Preparing the Workforce of Tomorrow. With a range of activities dedicated to nurturing new talent, IAF focuses on knowledge and how to help students and young professionals to grow, learn and evolve.
- Raising Awareness. With the help of its members and its global community, the IAF publications spread around the globe enabling the public to get a closer look at the information about space.
The International Astronautical Federation is a non-profit organisation devoted to spreading knowledge about space and supporting the development of astronautics for the betterment of humanity. With a long history of collaborations and achievements towards making “A space-faring world cooperating for the benefit of humanity,” it works hard to enhance powerful collaborations and build the conditions for a future where space and scientific knowledge prevail.
A few words about Libre Space Foundation
Libre Space Foundation is a non-profit organisation focusing on the development of open-source space technologies. Its mission is to support, promote and enable innovative ideas, projects and initiatives that promote space technology, space exploration and enhance knowledge. All the projects the Foundation runs and its operations are governed by the Principles of the Manifesto. This is why all the projects are open-source, designed and developed under open-source methodologies, operating in transparency and are accessible to everyone. LSF shares its vision of Space being accessible to all humanity not only with a number of organisations, university teams and research institutions but with its global and diverse community of contributors who put their expertise and continuous effort into developing open-source projects and tools. LSF has a wide range of projects under its wings ranging from Machine Learning for satellites (Polaris), satellite missions (UPSAT, QUBIK) to upstream space projects like deployers (PICOBUS) and of course, developing and operating the world’s biggest open-source network of satellite ground stations worldwide (SatNOGS). Libre Space Foundation is proud to be the first-ever member based in Greece to be joining IAF.
At Libre Space Foundation, we are always thrilled when we join forces with organizations and initiatives promoting the open-source development methodologies.
For this, we could not be more excited to announce our membership to RISC-V International.
A few words about RISC-V
What RISC-V is
RISC-V is an open-standard, instruction set architecture (ISA).
For those not very familiar with the term, an instruction set is the set of basic instructions a processor understands. The instruction set is part of the processor’s architecture. ISAs fall under two categories: the Reduced (RISC) and the Complex (CISC).
The RISC-V instruction set is designed to facilitate a wide range of uses and, it comes under an open-source licensing scheme making it available for everyone to use.
How it started
For a CPU design to be created, many experts from different specialities are required to contribute, making the cost of such a creative high. Some commercial vendors of ISAs charge royalties. But RISC-V follows an entirely different approach.
The project was initially begun at the University of California, Berkley in 2010 and it was the result of the collaborative work and effort of many non-affiliate-with-the-University volunteers. They contributed their time, effort and know-how in creating an open-source instruction set that would be useable for practical computers.
The aim was to come up with a non-proprietary, academically useable ISA whose usage would not require any fees and it would be versatile enough as to be integrated with any hardware or software. Instead of focusing on creating complex microarchitecture, the contributors of RISC-V focused on its usability and its successful design. The more functionality it acquired, the more popular it became. Over the years, the number of contributing entities which have been creating and releasing RISC-V hardware or operating systems supporting RISC-V has increased tremendously.
RISC-V supports small, fast and low-power implementations responding to the real needs of the users. This way, an array of designs has been built to fit as many uses as possible. By working with a good, open-source instruction set, you can focus less on software support and more on design; less on worrying about software, more on focusing on implementation. Its open intellectual property enables the modification, improvement, reusability and publication of updated, adjusted and robust designs.
Libre Space Foundation
At Libre Space Foundation, we believe that the future of humanity is Space but only experienced and explored following open-source approaches; in development, data distribution and governance too. These are principles which we apply to all our projects, both hardware and software. Though this might seem hard to implement, the truth is that it is not. Because if you take a closer look at all of our projects, you will see that they are guided by the same principles of openness and accessibility. All the tools and solutions we build are modular and reusable so as to serve as level-field, highly-reliable solutions. The hardware design, schematic design, Printed Circuit Board (PCB), firmware we create, everything is non-proprietary. Because what we aim for is creating tools which are:
- versatile enough to respond to the users’ needs
- powerful enough to fuel versatility
- reliable enough to function well in extreme conditions and
- reproducible to such an extent that gives the user the opportunity and the freedom to build what
they have in mind regardless of the types of tools they decide to use. Thus, they might as well use the tools we provide them, but they can just as easily opt for any other set of tools available. It does not matter, and their choice does not affect their creation because, from our part, the solutions provided are easily integrated. This way, functionality, modification and reusability are not obstructed nor affected in any way, as they do not rely on any proprietary solutions.
RISC-V International and Libre Space Foundation: where the two converge
For us at Libre Space Foundation, becoming a Member of RISC-V International is a great honor as we see eye-to-eye with it. This is a partnership towards making open-source even more powerful and enhancing the efforts to familiarize wider audiences with it.
Libre Space Foundation functions and operates within a niche industry, and this is particularly challenging at times. We do believe that the challenges arising can be dealt with effectively when open-sourced methodologies are applied. These should be implemented widely not only when it comes to creating Space Technologies but also on ISA too. End-to-end, open-source methods to enable modifications enhancing functionality, to bring in new users and expand the pool of active contributors.
What is more, we believe that the significant challenges that we face within the space industry can be managed successfully through the pursuit of strategic partnerships with space agencies, academic institutions and other organizations that believe in the power of openness and collaboration.
All these are part of how we see innovation, development and progress should unfold, and for this, we have joined forces with RISC-V International.
In May 2020, we announced that Libre Space Foundation would be mentoring two projects for the Google Summer of Code 2020. As the students are about to submit their final work, we would like to share with you an overview of their achievements/progress this summer. One of the GSoC proposals is to create a Python module to assist SatNOGS operators in tackling RF collisions. More details on the progress of this project and an update about it will be given to you on the SatNOGS blog within the next weeks.
Today, however, we will be focusing on the hard work Adithya Venkateswaran has put in as a valuable member of the Polaris project team. Adithya maintains a personal blog walking the readers through his work and the final post on his GSoC contribution was the inspiration for this post.
Polaris: a quick technical overview.
Before delving into Adithya’s work, allow us to provide some background information, helpful context on what Polaris is about.
Polaris is a command-line based, satellite-telemetry analysis tool using machine learning. Space operators usually have to deal with a lot of telemetry parameters from their satellites, and it is often hard to understand how they impact each other on a global picture. Polaris makes use of the XGBoost algorithm for eXtreme gradient boosting to predict every telemetry in the satellite and provide their inter-importances (like a dependency without the causality). The importance of links between telemetry parameters is represented as a graph in a web-based 3D interface. 3d-force-graph is the graph component used for the output.
Practically Polaris consists of four distinct parts:
- polaris fetch: It fetches data from various sources, such as telemetry from the SatNOGS Network and Space Weather from SWPC (NOAA).
- polaris learn: A machine learning (XGBoost) based module that analyses the relationship of all the data “fetched” and provides a JSON graph file as an output.
- polaris viz: A 3d graph-based visualisation module, which offers an intuitive graph representation of data.
- polaris anomaly (WIP): An autoencoder-based tool (betsi) that detects anomalies in telemetry data and warns satellite operators. In other words, deep learning for space operations.
Adithya worked on several parts of the project and added useful functionality. His main contributions to Polaris were two new modules “Vinvelivaanilai” & “Betsi”.
Vinvelivaanilai is the word for space weather in Tamil. Vinvelivaanilai is a Python module which uses File Transfer Protocol services to fetch space weather data from SWPC/NOAA’s servers and stores it locally or in InfluxDB-based docker-containers.
It also contains functions to parse TLEs and OMMs (any GP data) and propagate the orbit to find the position and velocity of the satellite at any time.
The red coloured nodes in the following graph are derived from Vinvelivaanilai.
Betsi is shorthand for “Behaviour Extraction for Time-Series Investigation”. It makes use of deep-learning techniques to detect anomalies in the telemetry data. The spectrum of an anomaly is broad and it ranges from a simple orientation change to a mega-scale explosion. An explosion capable enough to wipe out all of humanity according to Adithya’s post. But of course, we wouldn’t like the latter to occur.
As the Betsi development team states
If it happened, betsi detected it*.
* You can always change the sensitivity though 😛
In the following graph, the black dotted lines are the breakpoints. Keep in mind though, that at the moment, we are working on finding a better way to represent 200 parameters used for anomaly detection. If you believe you can contribute to the project with ideas, your expertise and knowledge, don’t hesitate to reach out to the team by joining their matrix/element chatroom
As Adithya stated in his blog post, participation in the Polaris project was a more diverse learning experience than what he had expected initially. To this, we believe, that the catalytic factor was the Libre Space community and its continuous effort to share knowledge. Adithya has been an invaluable and active member of this community from the very start. And we could not be more thrilled to see him contribute and participate with such a zest and devotion.
- Adithya learned to read, comprehend in-depth and implement research papers contributing to Betsi’s creation.
- He learned to interface to FTP over Python and learned to create a stable API to fetch space weather data.
- Tested several DBMS to find the best pick for space weather data which will also be future proof.
- He familiarised himself with the Polaris API in-depth to be able to add weather data. Enabling, thus, Polaris to provide better results.
- While also contributing to improving the web graph user experience.
- Currently, Adithya is working on analysing a way to skip the normalisation steps (which converts data to SI units), which will allow Libre Space Foundation to support all satellites whose telemetry can be decoded. At the same time, he is collaborating closely with a satellite team to perform further tests.
- As an active member of our community, Adithya has helped greatly guiding new users interested in Polaris to set it up.
In the future, Adithya and the rest of the Polaris team will be working on integrating Betsi into Polaris and create a way to represent Betsi’s data in a meaningful and useful manner. They will also focus on improving the experience of the visualisation module and adding more input from SatNOGS in Polaris as soon as all the afore-mentioned changes and improvements are implemented.
Adithya’s final GSoC blog post carries a very moving message for his mentors.
All of this was possible because of your support. You not only helped me in my work but also helped me grow as an individual. I learnt so much more than just programming. I learnt to respect and enjoy the open-source culture, make my own decisions, put my point across and defend it. I learnt to be self-sufficient but also approach you when I need it (you were always there to guide me). If any of you are reading this, please know that you have helped me realize the potential I carry in me and I will forever be indebted to you for that!
We wholeheartedly believe that both on an individual and on a community level, our contributors deeply desire to empower their fellow community members and work hard towards achieving that. They do so with as much devotion as we have for the open-source technologies and methodologies. It is the inspiring combination of our community (and its members) and the Open methodologies we follow that empower everyone to continuously dream, contribute and innovate. We truly believe Adithya is one such valuable member of our community, and we cannot wait to see what the future holds for him and see him thrive.
In order to understand what gr-leo is and why it is considered to be a powerful, open-source simulation tool, let us first take a look at why it is necessary. Gr-leo is here to fill a gap and to ensure that the quality of communication between a satellite and the ground station is not impaired in any way.
For the success of a satellite mission, there are many conditions that should be taken into consideration. Telecommunication between Earth and a satellite plays a vital role in that success. However, the quality of the telecommunication can be majorly affected by a number of parameters. These can impact and reduce the quality of transmission between Earth and a Satellite. Some of these parameters are: the relative motion of the orbiting satellite, the operating frequencies, the antenna set-up and of course the atmospheric phenomena. In order for the parameters to be predicted, the system should undergo extensive testing under realistic channel conditions and not in a lab environment as that would not be realistic enough.
Gr-leo is an open-source, simulation tool that facilitates the testing of all these parameters under realistic channel conditions. It allows for the continuous testing of a system’s development, debugging and evaluation. This way the channel conditions are simulated to be realistic enough and indicative of the failures which might affect telecommunication.
Gr-leo is built with the implementation of a GNU Radio module. An Out-of-the-Tree module is a GNU Radio component that no longer lives under the GNU Radio source tree. This means that one can use the basic GNU radio blocks and reconfigure them so as to extend their functionality as they deem necessary. The new blocks created are also available to the community and can be combined with the existing blocks. This is the case with gr-leo. It adheres to the programming notion of blocks as it is found on GNU Radio, but there are new blocks created to suit the project’s needs. GNU Radio provides the community with a vast range of signal processing and channel estimation blocks. However, these can not extensively cater to the needs of a space telecommunication channel. This is why in order to build gr-leo new processing blocks were configured; with each block simulating a different component found in the space channel communication.
A more detailed look into gr-leo
Gr-leo is an open-source, space channel simulator; a tool created to facilitate the simulation of the Earth-Satellite system operation and to explore the possible failures that may occur in space channel telecommunication.
At the core of gr-leo is the channel model definition. The channel model definitions link the different components making up the Earth-Space communication system with a single GNU Radio block. The blocks are synchronous. Their functionality is to pass the signal from the input port to the worker function, alongside a pointer to the output buffer for the duration of satellite observation. A channel model block accepts a list of required parameters that need to be taken into consideration during the channel simulation. Gr-leo is efficient and versatile not only because it creates the appropriate realistic conditions for testing but also because it explores a wide range of parameters in great detail.
Below is an example of a UPSAT flowgraph combining gr-leo and the UPSAT transmitter. Both are included in the gr-satnogs module.
By using the gr-leo module with the GNU Radio Companion integrated blocks we succeed in:
- Defining a satellite and describing its orbit by providing a valid TLE.
- Defining a tracker by specifying its coordinates, the operating frequencies, the antenna type and an observation time-frame.
- Defining the communication channel model and specifying the desired attenuation types which need to be simulated.
Once these parameters are specified, the channel model block attenuates the input signal according to the defined channel model and the orbit of the satellite described by the TLE.
Gr-leo is an open-source space channel simulator developed as a subactivity of SDR Makerspace. It is created to facilitate testing (under realistic conditions) of all those different parameters affecting the quality of transmission between a ground station and an orbiting satellite. Built on the GNU Radio’s programming blocks it adheres to the open-source principles. It extends the use and functionalities of the basic GNU blocks in order to be able to serve the needs and the purposes of a space telecommunication channel. gr-leo is open-source and the blocks created are available to be used by the GNU Radio community. Contrary to other telecommunication channel simulation projects which are proprietary and provided under expensive licenses, gr-leo is open-source, available for everyone in the GNU Radio community to use and it is a powerful and efficient simulator.
If this sounds interesting to you and you wish to find out more you can take a look at the public repo, the wiki and the documentation pages! Feel free to join our community to share your thoughts and ideas!
Libre Space Foundation is an organization dedicated to creating open-source, space technologies. Often we come across a project that wishes to join us, or we are approached by exciting initiatives to assist them in their endeavors. However, joining LSF as a project is a process that must meet specific criteria and particular requirements. In this article, we wish to clarify a project’s eligibility to join LSF while at the same time, we elaborate on the pillars of the Libre Space Manifesto and the philosophy governing Libre Space Foundation. This article is not about the management, the organization or the development process alone. It is about the principles fueling our approach. It is about how and why we do things differently.
Joining the Libre Space Foundation
For us, the Manifesto is found at the core of our operations and processes. Thus, all projects and all project decisions must adhere to the Libre Space Manifesto. The projects must abide by the Manifesto principles starting with the primary principle that Space should be open and available to all humanity. All the projects that join us are devoted to Space being available to all and open for everyone to explore. All projects we onboard work towards creating opportunities for learning, exploring innovative ideas and bringing Space closer to the public (such as LSTN offering public library communities the chance to build and engage with space technology).
For the principles of the Libre Space Manifesto to materialize, there are four pillars to which all our practices adhere.
- Open-source, copyleft license.
Based on the Libre Space Manifesto, the projects joining LSF must have an open-source, copyleft license for anything developed and released within the project. For those not familiar with the term, a copyleft licensing scheme is a process that allows people to freely distribute copies of a certain work or even modified versions of it. Provided that the same rights will be preserved in derivative works created later down the line.
It should be noted that we strive to use open-source tools and applications, and it is imperative for the projects onboarded to adhere to the open-source methodology at every step of the workflow. In practice, we develop and use open-source tools and software, we modify them, explore their potential, and then we give back to the open-source community by distributing our work under an open-source, copyleft license.
The significance of this approach is that new types of software, features, projects and initiatives are created under an open-source license which enables their use by everyone who needs them. This approach delivers free solutions and tools and it guarantees that new ideas can continue to explore new potentials, fuel solutions and features for other individuals to enjoy.
- Open Data (available to everyone in the community or to anyone who is interested).
According to the Libre Space Manifesto, all findings, all data should be available to everyone. Open data has always been in the core of our operations. The SatNOGS network, our global network of satellite ground stations, is a collaborative, world-wide community which receives satellite data. The observations made are stored online in the SatNOGS Database and are available for everyone to see and use. SatNOGS Database is a machine-readable data resource. The Open data approach we have at LSF has helped many projects, teams, universities to study Space and satellites in much detail. It has facilitated and helped other projects too. Polaris, par example, uses telemetry data that is received by the SatNOGS network of satellite ground stations.
- Following Open Development processes.
At LSF, true to our beliefs, we use open development processes for our projects. We use Gitlab for organizing, managing, developing our projects and for the teams and team members to communicate efficiently. Since our collaborators, contributors and team members come from all over the world, Open Development processes are the best way to include everyone in the development process. This way we achieve a natural flow of conversations and contributions as the team members work towards accomplishing a common goal (or towards working on completing a project).
Every contribution, every idea and every discussion benefits not only an individual but the whole team, the whole project and often the contributions made are beneficial for other projects too. This, of course, is one of the advantages of open-source and open development.
Sequentially, under an open development process, documentation of the code is open for the public to view and detailed to allow for a better understanding of how a project works. New members can be introduced to the complexities of a project faster, and a greater audience of collaborators can contribute more easily. Code is tested in a collaborative way focusing on high-quality but often achieving fast progress, too. The team members can review the code, offering feedback, flagging problems early on, suggesting solutions and resolving issues. Quite often, this discursive approach to a project and the exchanging of ideas leads to the emergence of new and innovative projects and useful tools.
Open development processes is a common practice for us; an approach taking place on all channels of communication: on Gitlab, on the LSF Riot Channels and our Community Forums too. Consequently, this takes us to the next significant pillar of the Libre Space Manifesto.
- Open Governance (with transparency and direct communication) for all projects.
As mentioned above, we try to use tools in our projects which are open-source. We use Matrix/Riot for all communications concerning the projects. We have a buzzing, collaborative and constructive community where individuals contribute. They share their worries, their problems, their achievements and their ideas. As project discussions and interactions are held in public, they become accessible to everyone, and everyone can join. This, in fact, has a catalytic impact on the way the community manages itself while working as a whole. The projects govern themselves, delegating responsibilities and asking for assistance or advice always having the project’s best interest at heart. Though different projects have different maturity levels and thus different governance paradigms, yet they too follow the general open governance principles. These include unrestricted participation, open and clear communications and decision making processes, and accountability for project roles.
Being part of the Libre Space Foundation
Once a project is given the green light to join LSF, then it receives the support and the tools necessary for project development, operations, legal guidance and even marketing, branding and communications. LSF guides the project through to success and completion. If your project meets all the necessary requirements and provided it adheres to the Libre Space Manifesto principles, LSF will give you all the assistance, guidance and tools to see it through.
If the way we do things sounds fascinating to you and you wish to join us, feel free to check out the Libre Space Manifesto! Don’t hesitate to show your support by signing up and sharing it with your friends and network!
For the second year in a row, Libre Space Foundation was selected as a mentor organisation for the Google Summer of Code initiative. The application period has closed and the results are in, and so it is with great excitement that we announce the two projects we will be mentoring over the next few months.
The first project titled “Deep learning for Cubesat Behavior Segmentation with Collection of Contextual Information” will be working on the Polaris codebase. The project aims at supporting spacecraft operators by predicting the behaviour of their satellites and linking it to various data sources. There is a data challenge in collecting and sometimes in converting into time series. This data collection phase will allow for better information when understanding and estimating the behaviour of a spacecraft. External sources of data, namely, orbit propagation, solar and magnetic events, and various elements of space weather, will be some of the external sources providing the data needed. The machine learning approach employed for Polaris will transform these data sources into learning features so that a spacecraft’s behaviour is not only predicted but also explained by the “machine”. Deep learning means that the project is exploring the usage of different neural network architectures of several layers. The project is undertaken in close collaboration with the amazing team of the Polaris project.
The second project that Libre Space Foundation will be mentoring is a “Python Module for RF Collisions”. This project’s goal is to tackle an issue that troubles satellite observers quite frequently. With the number of deployed satellites in constant increase, it is often that satellites transmit with the same or near frequencies. This overlapping of frequencies interferes with the results of the observations and affects their accuracy. Thus, the project we will be mentoring aims at dealing with this exact issue. By building a Python module that will allow the ground station operators to specify the time and the location this interference occurs. This project is closely related and linked to SatNOGS and it will be used by the SatNOGS network as an internal or an external tool to let the observers know which other satellites are expected to be found in the results of their observations.
Google Summer of Code is an annual program offering university students the opportunity to work on open-source projects during their summer break while earning a stipend! Libre Space Foundation is devoted to working on open-source space technologies and you can find out more about our Principles regarding open-source and space in our Manifesto.
This year’s Google Summer of Code application period has been indeed a groundbreaking one as the initiative received 8,902 applications submitted by 6,626 students from 121 countries. These applications were reviewed by 199 mentoring organizations. Eventually, 1,199 students from 66 countries were selected. We are thrilled to be part of this grand initiative. But we are also excited and looking forward to working with our students over the next few months. Congratulations to everyone and welcome aboard!
Libre Space Foundation is devoted to the vision of open-source technologies in space, and for this, we often join forces with researchers, individuals, and teams who share this vision with us. One exciting project we have taken up is the QUBIK Project.
A few words about the Project
Our love for space has brought us in collaboration with Firefly Aerospace and the DREAM payloads program. This is a global competition to host academic and educational payloads as rideshare participants on the inaugural flight of the Firefly Alpha launch vehicle. For this project, we have been working together with FOSSA Systems and AMSAT EA. We have developed two PocketQube satellites, QUBIK-1 and QUBIK-2, and PICOBUS, a PocketQube deployer.
The satellites are expected to have a short lifespan of up to 3 weeks of orbit. Regardless of how short-lived they will be, though, they are built to perform Amateur radio experimentation. While those amateur radio experimentations will be taking place, the SatNOGS network of ground stations will be receiving signals from these satellites. By exploiting Doppler Variations, the network of ground stations will perform orbit determination and satellite identification as early as possible. This will utilize the benefits and the capabilities of the SatNOGS network to the fullest and demonstrate the Space Situational Awareness aspect of it.
How the Project has been progressing for the last few months
On the 12th of December 2019, the thermal vacuum test for the PICOBUS took place at Instituto Nacional de Técnica Aeroespacial, and on the 16th of the same month, the vibration test was conducted at the NanoSat Lab of the Polytechnic University of Catalunya. A few months later, on the 8th of February 2020, our team working at Hackerspace.gr completed the assembly of the PICOBUS and QUBIK-1 and QUBIK-2. The next day marked the bake out day for the project at the Institute of Electronic Structure and Laser. Lastly, on the 12th of February 2020, at the NanoSat Lab, the vibration acceptance campaign took place for PICOBUS, and so did the Protoflight campaign for QUBIK-1 and QUBIK-2. At this point in the process, the software is being developed so that the project will be able to facilitate all the amateur radio experiments that need to be carried out.
QUBIK-1, QUBIK-2, and the PICOBUS deployer form an exciting project for which we have worked hard, and we have collaborated with inspiring teams. As the development draws to completion we are excited to see what this project will achieve.
If you find this project exciting too and you wish to find out more about Qubik you can follow the open-source repositories of the project.
An essay on the necessity of an open data approach for space.
With tens of thousands of objects being already in orbit and hundreds of thousands coming up in the near future, it is no secret that keeping track and predicting orbital attitude and position for those objects will become imperative for viable and sustainable space operations and explorations. Space Situational Awareness (or SSA for short) is a multi-million dollar effort undertaken by various agencies, governments, and organizations around the world many times combined with Space Weather and Near-Earth Objects tracking. Most (if not all) of those efforts are deeply rooted in their defense-related past. The military branches of their countries directly oversee many of them. For example, in the US, SSA services are operated by the 18th Space Control Squadron, a unit of the US Air Force, while in Russia, the 821st Main Centre for Reconnaissance of Situation in Space is operated under the Russian Space Forces. Inherently, running such services under a military branch imposes heavy restrictions with regards to data openness and transparency to operational capabilities of the Networks of radio and optical tracking equipment used by them.
Let’s have a more in-depth look into the current known efforts and their shortcomings when it comes to data openness.
The European Space Agency Space Surveillance and Tracking (SST) segment
The European Space Agency has been investing tens of millions of Euros since 2009 to develop a program around artificial objects tracking and orbit analysis. Unfortunately, between non-functional websites and awareness newsletter-style reports we have seen little of its actual technical data, let alone any open orbital data coming from it. Statistics do get shared from DISCOS (Database and Information System Characterizing Objects in Space) but the access to data is gated (restricted and request-only for certain entities). We should expect better from a publicly funded non-military organization.
Russian Military Space Surveillance Network (SKKP)
The SKKP is part of the Russian Space Forces (Космические войска России). The Network of multiple radars and ground stations across Russia was initially part of the missile early warning system of the Soviet Union and gradually gained its independence and specialization to detect satellites, identify them, and to discern their orbits. It maintains the Russian catalog of space objects, and provides data that could be used to support space launches, feed an anti-satellite program, and provides intelligence on hostile military satellites. It is the Russian equivalent of the United States Space Surveillance Network. No public data is available from SKKP.
The United States Space Surveillance Network (SSN)
The US SSN detects, tracks, catalogs, and identifies artificial objects orbiting Earth. The system is the responsibility of the Joint Functional Component Command for Space, part of the United States Space Command. Its facilities include dedicated and collateral sites around the world, consisting of tracking radars, detection radar, optical telescopes and imaging radars with systems like Ground-Based Electro-Optical Deep Space Surveillance (GEODSS) and Space Surveillance Telescope (SST). The data from SSN are analyzed by the Combined Space Operations Center (CSpOC), which also is part of the US Space Command. Besides its primary military function, CSpOC and the 18th Space Control Squadron are responsible for maintaining their space catalog of objects and running the SSA sharing program targeted to the US, foreign government, and commercial entities. This sharing and dissemination platform (space-track.org) has been the primary source of SSA data for most users worldwide. It has been fueling further dissemination platforms like Celestrak (with the additional analysis done by AGI). Although the nature of the data seems to be open and accessible with modern APIs and convenient formats, their license is highly restrictive. The license is restricted to personal use, banning further sharing of data or derivative data, to the point that most current usages of space-track.org data can most certainly be marked as illegal. That continuing legal threat, combined with the filtering of the data available concerning military payloads from the US and its allies, allow no doubts for the restrictive non-open data nature of space-track.org.
Space Data Association (SDA)
SDA is an international organization of satellite operators working to, in part, enhance the “accuracy and timeliness of collision warning notifications.” The Association is driven by the member’s needs for in-time SSA information, with the members being mostly GEO satellite operators (EUTELSAT, INMARSAT, and others). The data shared amongst its members are not made public, and their source is the satellite operators themselves.
International Scientific Optical Network (ISON)
ISON is an international project, currently consisting of about 30 telescopes at about 20 observatories in about ten countries. ISON, as a civilian global space surveillance system, covers the whole GEO and is capable of searching and tracking objects both on GEO and various classes of HEO orbits (GTO, Molniya, etc.). From the published papers and reports coming from the network, it is clear that the tracking capabilities of ISON are quite capable. Unfortunately, there is limited dissemination of their data, gated, and only valid for the analysis of past observations, not for future permissions. Participation in the Network seems to be gated too since there is no clear path of joining or an established process to contribute.
The amateur satellite tracking community – SeeSat-L mailing list
A network of amateur satellite trackers provides positional measurements as well as orbital elements for a subset of objects, both in LEO, GEO, and HEO. This subset consists primarily of military payloads from the US and its allies (e.g., France, Germany, Israel, Japan) for which the 18th Space Control Squadron does not release orbital elements. This network originated from satellite trackers initially involved in Operation Moonwatch, the citizen scientist program, to track artificial satellites since the launch of Sputnik. Observers in this network are increasingly using more sophisticated sensors and software, increasing the accuracy of the orbital elements, as well as the number of objects that are tracked. Dissemination of data is open and readily available to the public, although confined mostly around the subset of objects that represent the group’s interest.
Various militaries around the world maintain a particular SSA capability, and in some cases, we do have public data around their existence. For example, the French military operates the GRAVES radar to track objects in predominantly LEO, while Germany operates GESTRA under GSSAC with multiple locations. Eight EU Member States (France, Germany, Italy, Poland, Portugal, Romania, Spain and UK), with representatives from National Designated Entities and Ministries of Defence and EU SatCen participate in the EUSST Cooperation, joining SST efforts. No data or orbital elements are made public.
Commercialization of SSA services has been an approach that some private for-profit companies are exploring. Most notably, LeoLABS is providing paid SSA services for LEO objects, using data from their radar facilities. No data or orbital elements are made public.
The need for open data in SSA
We in Libre Space Foundation believe that all people shall have access to outer space, space technologies, and space data. Space Situational Awareness data are critical for our understanding, peaceful coexistence, and exploration of space. We believe that to achieve that, all SSA data should be gathered, processed, licensed, and disseminated as Open Data.
The benefits that Open Data can bring to SSA:
- Transparency. Open Data supports public and comprehensive oversight of governmental and agency activities. For instance, Open Data makes it easier to monitor all space activities regardless of their classified or not status. It also encourages greater citizen participation in space affairs and supports verifiability, collaboration, and cross-checking of analysis.
- Service Improvement. Open Data gives citizens and organizations the raw materials they need to engage in the space sector and contribute to the improvement of public SSA services. For instance, anyone can use Open Data to perform their orbital determination analysis and engage with existing services for improvement suggestions.
- Efficiency. Open Data makes it easier and less costly for governments and agencies to discover and access their data or data from other organizations, which reduces acquisition costs, redundancy, and overhead. Open Data can also empower anyone with the ability to alert for gaps in public datasets and to provide more accurate information.
- Innovation and Economic Value. Public data, and their re-use, are critical resources for social innovation and economic growth. Open Data provides new opportunities for governments and agencies to collaborate with anyone by giving open access to data about those services. Businesses and entities are using Open Data to understand potential markets better and build new data-driven products.
The open way forward
As Libre Space Foundation, we are committed to establish and act upon an open way forward around SSA. We will be guided by our principles, express them in our manifesto, examine the technical possibilities, and craft a development and implementation way ahead.
The following principles should guide space Situational Awareness:
Unconstrained access to all data related to SSA, licensed appropriately, and treated as a public resource.
Modern technology stack
The technical implementation should be based on a modern technology stack, modular, expandable, and open source.
Due to the fundamental nature of the SSA data, we believe that verifiability should be an essential aspect of our data and processes, achieved through the openness of our technology stack, allowing for auditing by anyone.
Openness in participation
SSA data generation, processing, and consumption should be open for participation to all who wish to contribute without gated access.
Sources of SSA data can be categorized in the following groups:
Active RF tracking
Essentially Radar systems emitting RF signals that then can be received and analyzed in a closed-loop order. This methodology is a high-cost, high-quality approach undertaken by most of the active SSA players currently (mostly governments through their military branches).
Passive RF tracking
Opportunistic RF tracking is an SSA surveying method utilizing pre-existing RF signal sources beyond someone’s control (radars or other transmissions), tracking the reflections on space objects from those sources. Given its nature, it can yield valuable results but, at the same time, is at risk of intermittent operations since one cannot have control over the origin of the RF source.
Tracking signals (Telemetry or Telecommand and Control) from active space objects and specifically their doppler shift properties can yield substantial data that can be translated to quality SSA measurements. Although such an approach is limited to active space objects, it requires minimal development costs since it can utilize the existence of a global RF ground station network (like SatNOGS) without any additional changes needed to the space missions.
Optical tracking of visible light reflected upon space objects provides one of the best SSA data-producing methods. Readily available sensors, lenses, and mounts can be used to capture optical observations of space objects, yielding high-accuracy results. Its shortcomings are its dependence on sky and timing conditions and for some orbits its need for high-end costly optical systems (e.g., fast telescopes with sensitive sensors)
ID-tags and experiments in LEOP
A relatively modern and innovative approach would be to equip space objects with active or passive ID tags emitting identification codes passively or when probed, allowing for early identification and continuous tracking of those objects. Since this method requires additional development and cost for missions, it is imperative to standardize it and for a low-cost open-source implementation to be delivered, readily available for integration on future missions. Such an approach draws many parallels to existing models of tracking and monitoring on other domains (e.g., AIS for marine objects and ADSB for airborne objects) and also requires a legislative mandate to be effective, which in turn involves policy changes on a universal scale.
SatNOGS DB as a hub of information
SatNOGS DB has established itself as a hub on RF related information for hundreds of space missions so far. Given then the source of information is crowd-sourced and continues to expand, we believe that SatNOGS DB can be furtherly expanded to include SSA information and act as a hub for multiple sources of SSA data and their derivatives (orbital elements, conjunction reports, etc.) Since LSF develops SatNOGS DB as a modular project allowing for multiple sources and data consumers, we could envision an ecosystem where the processing of this data (automatic or manual) can also happen outside the SatNOGS DB instance and re-submitted for sharing through it. Collaboration with existing established hubs or information (like Celestrak/AGI) and up and coming open data approaches on specific subsets of SSA data (like TruSat) will be vital for establishing a collaborative and sustainable ecosystem around open SSA data. To that end, we will like to invite all possible collaborators to engage in our efforts and the public discourse around them.
Obtaining open SSA data – Developments for Libre Space Foundation projects
The SatNOGS project provides natural extensions that will allow the Libre Space Foundation to provide open SSA data:
LEOP identification work
The SatNOGS network of ground stations observes satellites transmitting in the amateur VHF and UHF radio bands to demodulate and decode satellite telemetry. Telemetry is stored publicly in the SatNOGS database (SatNOGS DB). The observations rely on orbital elements provided by 18SPCS/CSpOC, redistributed by celestrak.com, CalPoly, or AMSAT, which are used to perform Doppler correction and antenna pointing. The combination of SatNOGS Network and SatNOGS DB allows LSF to provide independent data on the identification of satellites. Satellites with active transmitters can be identified through either a priori known transmitter frequencies, modulation schemes, and demodulated telemetry containing satellite call-signs. The orbital elements used for Doppler correction and antenna pointing allow LSF to determine which orbital elements match the observed frequencies of an identified satellite, hence linking a satellite to CSpOC orbital elements. LSF is currently already sharing this SSA data publicly with TS Kelso (Celestrak/AGI), as well as individual satellite operators. This functionality could be expanded to frequencies outside of the amateur VHF and UHF bands (i.e., 401MHz, 466MHz, S-band).
More information about this effort can be found in our satnogs-ops repository.
Tracking RF transmissions
LSF is currently developing functionality to extract Doppler curves from observations obtained through the SatNOGS network of ground stations. Observations are presently Doppler corrected using orbital elements by 18SPCS/CSpOC. Still, deviations of the observed frequencies, either from recorded spectrograms (waterfalls) or demodulated telemetry, can be used to obtain Doppler curves. These Doppler curves can be used to constrain orbital elements. They may allow LSF to generate a catalog of orbital elements to track satellites that are observed through the SatNOGS Network. This functionality would be available for actively transmitting satellites, and likely limited by the time accuracy and frequency stability of SatNOGS stations, as well as the frequency stability of the transmitter onboard the satellites.
Passive RF tracking
Currently not under development, but SatNOGS client/Network/DB could be expanded to include the estimation of orbital elements from active radar reflections, possibly using a set of dedicated stations spread over a region (e.g., Europe). Such an approach would generate Doppler curves and orbital elements for any object bright enough to be picked up, though only feasible if radars are active (outside of LSF control). We should explore the legal aspect of such an endeavor since there are unanswered questions around it in various jurisdictions.
Network of Optical Ground Stations
Building on the experience of designing the SatNOGS open-source framework for demodulating and decoding satellite telemetry using cheap off-the-shelf hardware, LSF is investigating developing a similar open-source framework for video and photo-based satellite tracking ground stations. Using recent CMOS technology as well as software development, automated detection, identification, and position determination of LEO satellites in video observations is feasible. This approach would generate positional measurements that serve as input to the determination of orbital elements of satellites, as well as to characterize the optical behavior of satellites.
LEOP and ID-tag experiments
Through the development of its next space missions QUBIK-1 and QUBIK-2, Libre Space Foundation is testing In-Orbit a set of technologies to allow for the earliest identification possible of a space object, based on its unique RF transmissions, using the global aspect of the SatNOGS Network.
Join us on this open way forward for Space Situational Awareness data. Contribute to the repositories, and join the discussion in our forums.
Per liberum, ad astra.