LimeSDR Mini Hardware Donations from ESA and MyriadRF Announced

Thank you to European Space Agency and MyriadRF for giving Open Research Institute the opportunity to get LimeSDR Minis into the hands of some very amazing people doing open source space communications research and development.

ORI and Phase 4 Ground are very proud to present the following international recipients. We commit to supporting, enabling, promoting, and publicizing their work.

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Sahana Raghunandan, USA

As part of discussions at the 2018 GNU Radio Conference DVB-S2X Block Party, one of the functionalities of the demodulator that was identified as needing additional review and testing was the frame synchronization and symbol timing recovery loop. The goal of targeting LimeSDR is to modify and test existing GNNU Radio flowgraphs related to this subsystem of the demodulator. In order test this functionality independently, it is assumed that signal captures at the input to the baseband demodulator will be available.

Sahana Raghunandan is a researcher at Virginia Tech and an independent consultant focusing on satellite and terrestrial systems engineering including waveform design & implementation and interference analysis for spectrum management. Her experience includes design and FPGA-based implementation of waveforms for satellite broadband modems and satellite ground systems architecture with emphasis on modeling and simulation of cross layer optimization techniques. She has also worked on platforms and architectures for software and cognitive radio networks. Her research experience also includes design of modules for radar data acquisition, system integration of radar depth sounders and application of synthetic aperture radar techniques for ice sheet tomography.

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Jeremy Reeve, New Zealand

Jeremy has been working on VHF and L-band LNA designs. He has been running qucs simulations to look at optimum noise matching and stability circles and the like. His goals are to contribute RF hardware and baseband/FPGA content. He expects to be able to work with his educational institution to create a project that will result in quality open source publications.

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Edson W. R. Pereira, Brazil

Edson is an open source advocate and extremely active in amateur radio. He implemented a GUI (SDR-Shell) for Bob McGwier’s and Frank Brickle’s DttSP SDR, has contributed code for Joe Taylor’s WSJT-X, and has been a primary contributor on many other projects.

He is a lead maintainer for the Phase 4 Ground polyphase filter bank repository and is heavily involved with Phil Karn KA9Q’s development effort for multicast IP SDR innovations and implementations.

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Matias LU9CBL, Argentina

Matias is active in many areas of open source space communications. He is part of a group working to build a ground station design that supports a wide variety of satellite missions.

He has a SatNOGS ground station that is making rapid progress through the development portal. He is working to build and test antennas to add to this station.

He is active in his club station (LU4AA), which plans to run a station with an azimuth and elevation rotor from Yaesu, 2 crossed Yagis for VHF, and 2 crossed Yagis for UHF. Multiple fixed station will be added for remote control, and the station will be added to the SatNOGS network after it is functional.

Matias is active on SatNOGS forums and has a blog at lu9cbl.blogspot.com.

It is critically important to increase the number of stations and people involved in satellite communications from the southern hemisphere. Matias is deeply committed to publishing, sharing, and supporting others that are working in open source space communications.

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David Fannin, USA

David Fannin KK6DF works closely with Phase 4 Ground volunteer David Viera and wrote the code for David Viera’s LMX2594 oscillator and CW beacon project. David Viera demonstrated this system at GNU Radio Conference 2018 to great acclaim.

David Fannin has worked on a number of oscillator and SDR projects, his github account is https://github.com/dfannin, and he is committed to open source development in advanced digital communications.

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Open Research Institute and Phase 4 Ground are honored to be given the chance to put advanced software defined radio hardware like the LimeSDR Mini into the hands of active developers across the world. We are ready to help make the most of this very generous donation to open source space communications work.

-Michelle W5NYV

HamSci Data Plane + Satellite (research questions and proposed work plan)

Link to PDF

Abstract
HamSci, or Ham Radio Science Citizen Investigation, advances scientific research and understanding through amateur radio activities. Primary cultural benefits include the development of new technologies along with providing excellent educational opportunities for both the amateur community and the general public.

The HamSci Space Weather System is a HamSci project. HamSci Space Weather Stations form a distributed radio network dedicated to space weather research. HamSci Space Weather Stations produce receiver data from transmitters associated with coordinated observations. Sensors range from ground magnetometers, to ionospheric sounders, to lightning detectors and more. The diversity of sensor types means a wide variety of radios can participate.

A collaboration between HamSci and Tucson Amateur Packet Radio (TAPR) was proposed at the Digital Communications Conference (DCC) on 14-16 September 2018 in Albuquerque, New Mexico. Discussions about custom software-defined radio hardware designed, built, and sold by TAPR as HamSci Space Weather Stations began at the conference and continued though a Google Group.

HamSci presented at the TAPR DCC Sunday Seminar. Slides introducing possible sensor types from that presentation are reproduced throughout the full document linked above.

The receiver network employs a wide variety of sensor types. Combining sensor data from disparate sources, when the end result has greater certainty, accuracy, or quality than if the data was used individually, is called sensor fusion. The HamSci Space Weather System, as proposed above, can be affordably accomplished through sensor fusion.

For example, a $150 dedicated lightning detector on a Raspberry Pi in Florida, USA can participate in this network with a $6331 USRP X310 station sampling at highest rate and bandwidth in Madrid, Spain. The inexpensive data from the lightning detector may enhance the data from the expensive radio and increase scientific knowledge. Another example is a set of five inexpensive radios configured as ionosondes. The data combined is better than any one station’s individual contribution.

Open Research Institute (ORI) proposed an open source cubesat as part of the network. Observing from ground and space simultaneously provides substantial additional scientific value. The receiver network can be coordinated to make scheduled observations that align with satellite passes. This can be enabled with SatNOGS open source software. See https://satnogs.org/ for more information about this open source satellite network on the ground.

ORI believes that the central challenge of the HamSci Space Weather Station project is not the radio hardware. It is how the radios are interconnected, what metadata is accepted, how observations are scheduled, how the interactions between different sensor data is modeled, and how the large quantity of data is handled, organized, and re-used over time. This is the Data Plane.

GEO and HEO Launch Update – Phase 4 Ground Supported Payloads

We don’t like keeping secrets. However, we do have some secrets.

The Phase 4B payload, and the other related projects that we have actively supported (like CQC) all require launches.

We have a launch with the Wide Field of View payload with the Air Force. The good news is how well we did in getting engineering approval for this launch. We have a ride. The bad news is the cost of the launch. It is $6 million and they can guarantee us about one year and not even guarantee us it will be over the United States. We have decided we cannot ask the community for $6M to support this launch. It’s just not a good deal for US hams.

Fortunately there’s been a lot of work going on behind the scenes for additional launches. This work has been going on for a while.

I can’t share the details. I can say that our prospects have never been better. Anyone following along and helping the project, anyone that has been with us through a lot of challenging experiences, deserves to know that we are absolutely serious, focused, and unrelenting in obtaining multiple launches for this technology.

Traditionally, an amateur launch would be announced and then a payload developed. With modern digital technologies taking significantly longer development time than legacy technologies, and with opportunistic short-notice launches becoming more the norm, this design pattern really can’t work for us. That’s one of the reasons we need to work hard, now, as if the launch was imminent. Howie DeFelice and I wrote an article for QEX about this.

Working hard without a launch date is a lot to ask of people that are not getting paid and in some cases not being given the support or recognition they should be getting.

In the new year, we’ll be doing just that and asking for more in terms of technology demonstration and development from the team. The next big technology demonstration will be HamCation, and the most ambitious goal for that is to have LDPC working on an FPGA with interactive controls. This is the heart of the coding part of the receiver.

A GNU Radio LDPC demonstration can be seen in a recent video report, and the GPU version can be run by anyone with a late model Nvidia GPU.

Until HamCation, our goal is to get the air interface into the best possible shape. We need to capture the excellent progress we’ve made and make it as easy as possible for upcoming payloads to say “Yes!” to Phase 4 Ground.

There’s plenty going on. Progress is good. Launch prospects are part of that good news. A lot of the work is invisible during the negotiating process, but we are working as hard as we can to make it more than worth the wait.

-Michelle W5NYV

Hardware Donation for Open Source Space Communications Work – LimeSDR Mini Kits Available

Thanks to the enormous generosity of MyriadRF, Phase 4 Ground has some hardware help!

Five LimeSDR Mini Kits have been given to Phase 4 Ground for open source satellite communications development work.

We want to get these into as many hardworking hands as possible! Write me today with your need and let’s get you up and running.

I recently set up a LimeSDR Mini with GNU Radio with one of our list members and it went very well. This is a wonderful SDR. The LimeSuite GUI allows prototyping with what feels like every register setting on the controller. Performance is very good.

For a talk about LimeSDR (and the extended frequency range chip) from Microwave Update 2018 from Mike Seguin N1JEZ, please see https://youtu.be/F76BzezuCmw

LDPC-BCH decode on the FPGA is a current area of great interest for us. LDPC-BCH is the forward error correction for DVB-S2/X. But, we are also interested in doing more with Polar codes. There is at least one open source satellite payload project that has specified Polar forward error correcting codes. There is very little open source work here, it’s cutting edge, and Polar codes are specified for use in 5G communications. Polar codes are the first family of error-correcting codes that achieve the Shannon capacity for a wide range of communication channels with efficient encoding and decoding.

The FPGA on the LimeSDR mini is the Intel MAX 10 (10M16SAU169C8G 169-UBGA). How far can we take it?

What else needs doing? How about a SatNOGS station with the LimeSDR mini? A proof of concept of Phase 4 Ground authentication and authorization scheme? Handling the Generic Stream Encapsulation streams properly from the downlink for amateur communications? Plenty to do! Dive in and we will help you.

Contact Michelle W5NYV [email protected] to sign on and get kitted up.

Open Source Low Density Parity Check Decoder for DVB-S2, DVB-S2X, DVB-T2 Working in GNU Radio

An open source Low Density Parity Check decode from Phase 4 Ground is working for DVB-S2, DVB-S2X, and DVB-T2 in GNU Radio, thanks to the efforts of Ahmet Inan, Ron Economos, and Charles Brain.

This is a big step forward for open source satellite communications.

Video report here:
https://youtu.be/fOYVOgybFKY

Out of Tree (OOT) GNU Radio module by Dr. MPEG here:
https://github.com/drmpeg/gr-dvbldpc

Decoder by Ahmet here:
https://github.com/xdsopl/LDPC

3D Printed Cassegrain Antenna Structures at 122GHz Demonstrated at Microwave Update 2018

Here’s a demonstration of a 3D printed Cassegrain antenna system for 122GHz amateur radio. It was presented in the demonstration room at Microwave Update 2018.

https://youtu.be/NbTWWNvtvOU

122 GHz is an amateur radio band. There’s activity and distance records and some contesting. 122GHz has significant attenuation due to atmospheric absorption. Specifically, oxygen gets in the way.

I’ve been working on a 3D printed rig for 122GHz. This was sparked by a request from Alan Devlin VK3XPD for a 3D printed subreflector for a Cassegrain dish. People generally get by with a flat subreflector, but you can get better performance if it’s a hyperbolic curve matched to the feed and parabolic dish.

So what is 122GHz good for? Well, car radar for one thing. That’s what Silicon Radar does. They’re a company in Germany, and they have a radar development board and Millimeter Wave Integrated Circuits (MMICs) for 122GHz. The patch antennas are actually on the chip. The dev boards were used in this experiment. They send out a wide chirped radar signal and measure the return. There is software provided by Silicon Radar that runs the dev board.

The goal for Microwave Update 2018 was to verify a 3D printed Cassegrain antenna design for 122GHz amateur use. This design was adapted from the Customizable Cassegrain dish by drxenocide on Thingiverse. Link is in the show notes.https://www.thingiverse.com/thing:1935824

This thing creates a customizable Cassegrain Reflector dish. It was created using the equations from the paper by Peter Hannan, “Microwave antennas derived from the Cassegrain telescope,” in IRE Transactions on Antennas and Propagation, vol. 9, no. 2, pp. 140-153, March 1961.

The antenna parts were designed, the 3d model specified, the parts were printed, the resulting pieces were metallized (with MG Chemicals conductive paint), and then the parts combined into their final form.

Design files and papers can be found here: https://github.com/Abraxas3d/122GHz

The assemblies were taken to Microwave Update 2018 and set up in the demonstration room. Here’s what happened next.

So what were the results? Here’s some screenshots from the Silicon Radar software with and without the Cassegrain antenna installed over the stock lens in the development board.

And, there’s more. Please read Mike Levelle’s wonderful report on his efforts with the Silicon Radar chip in building a simple 122GHz transceiver. Link is in the show notes.

Mike has a tremendous amount of expertise and enthusiasm for the higher microwave bands and is a fantastic mentor.

http://www.bay-net.org/docs/k6ml-122GHzradio-baycon2018.pdf

What’s next? Building a radio! Stay tuned and stay on the air!

http://microwaveupdate.org/

Open Research Institute – Open Source CubeSat Workshop 2018 Madrid, Spain

Bruce Perens was the keynote speaker at the Open Source CubeSat Workshop 2018 in Madrid, Spain.

Michelle Thompson presented a technical update on Phase 4 Ground activities and described recent progress with DVB-S2X receivers in GNU Radio.

Held at the European Space Astronomy Center in late September 2018, the conference drew 122 diverse and enthusiastic participants from 22 countries. Two days of presentations and workgroups resulted in a remarkable amount of progress and sharing in support of open source spacecraft and ground stations.

Below are links to notes from the four working groups in which Phase 4 Ground volunteers participated.

Open Source Satellites – Improving the Starting Point
SatNOGS Report and Discussion
Libre Cube Standard, Community Development
Hugh’s Blog Post

Links to video recordings of presentations will be released soon.

Open Research Institute at DEFCON 26

Amateur Radio and open source Amateur Satellite activities at this past week’s DEFCON were very successful.

Multiple talks across the somewhat daunting schedule provided plenty of opportunities to hear about amateur radio, open source satellites, modulation and coding, and ground station work. Phase 4 Ground had an opportunity to present at Cyberspectrum, and then helped host a Q&A the following day.

Open Research Institute had a booth in the WiFi Village Friday-Sunday. Services provided were the DEFCON ham radio license exam information/encouragement, SatNOGS information/handouts/stickers, Libre Space Foundation information/handouts/stickers, GNU Radio demonstrations and quick tutorials, FaradayRF information/handouts, SDR demonstrations, Trans-Ionospheric badges, Phase 4 Ground updates/recruitment/promotion, and more.

The landscape of amateur radio in space is diverse, interesting, and active. The audience at DEFCON is enthusiastic, positive, technical, and generally unafraid to build things and try stuff.

The Amateur Radio Relay League (ARRL) was there this year, and they are thinking about coming to GNU Radio Conference as well.

We met several university researchers and put them in touch with the right support networks to get their cubesats “off the ground”.

It’s hard work to be part of a event as large, loud, and busy as DEFCON. The attendance was estimated at 27,500 by Sunday. However, it’s very much worth it! It was great to meet so many people in person for the first time that we’ve gotten to know through electronic means.

We are solidly in the black on Trans-Ionospheric badge sales and are well on our way to funding the development board for Phase 4 Ground radios. Support and information here: http://openresearch.institute/badge/

We’ll be selling them online shortly. All proceeds go directly to support the non-profit ORI, and specifically for Phase 4 Ground project.

Next up: finding out how to improve representation for amateur radio on interplanetary missions from NASA. We’ll be at the Interplanetary Cubesat Workshop this week at Goddard Space Flight Center. We’ll have a poster session on open source satellite and ground station work, specifically allowed under ITAR 120.11.

Thank you to everyone that helped make this trip rewarding and fun with the encouragement, support, and materials.

DVB-S2/X Block Party at GNU Radio Conference

Hello everyone,
GNU Radio Conference is coming up in September. If you haven’t registered and want to go, please do at https://www.gnuradio.org/grcon-2018/
There’s a special event this year called Block Party.
It’s an effort to get DVB-S2 and DVB-S2X receivers in GNU Radio.
We will have our own room and tables and swag. We will have docents enthusiasm and test equipment. We’re looking for more! We’ll have documentation and refreshments.
We need blocks!
Most blocks needed for DVB-S2/X receive do, in some form, already exist. Some do not. Some just need additional modulation and codings added to them.
Receiver design is hard, but breaking it up into small blocks makes it tractable.
The DVB protocol documents are all open. There are implementation guidelines. See https://www.dvb.org/
There are several community members that are experts in this area. There is a team (Phase 4 Ground – find out more at https://phase4ground.github.io/) that needs DVB-S2/X to work in GNU Radio. There is a lot of interest from a variety of other groups including Libre Space, ARRL, AMSAT, and TAPR.
If you are able to contribute to this effort, I want to know about it! I am here to support it. I’d like nothing better than to complete the Block Party at GNU Radio Conference with working, tested, documented blocks for a DVB-S2/X receiver. This contribution makes our open source terrestrial and space radio designs for Phase 4 Ground possible, and also opens up a lot of other work.
The thing that is considered the hardest part is the LDPC FEC decode. We have an open source implementation that targets GPUs. We want to take this and get it into RFNoC. If you are working on this as well, we want to collaborate and support and combine and promote.
The GPU implementation (by Charles Brain G4GUO) of LDPC decode can be found at our repository folder here: https://github.com/phase4ground/DVB-receiver/tree/master/G4GUO-LDPC-on-GPU/DVB-S2XTxRx
Phase 4 Ground is devoted to an open source implementation of DVB-S2 and DVB-S2X for amateur radio terrestrial and space use. We are part of Open Research Institute. Learn more about this non-profit here: https://openresearch.institute/