Month: January 2019

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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 groupworking 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

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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.