Swarm-E (formerly known as e-POP)

In the spirit of making data from the Radio Receiver Instrument (RRI) onboard Swarm-E (formally known as e-POP) more accessible to the ham radio community, we have converted RRI's data into a ".raw" format so that it can be ingested into open source software such as Gqrx or GNU Radio.  We have done this for all RRI data related to the 2015, 2017, and 2018 ARRL Field Days.

We encourage everyone to help us identify hams in RRI's signal.  You can use the Gqrx tool discussed here, or you can use your own technique.  If you decode a ham's call sign, if you would like to share your technique, or if you have any comments or suggestion contact us and let us know! 

To help organize your findings, you can download a spreadhseet containing that you can fill out and send to us.  Feel free to create your own spreadsheet or modify this one.  

Swarm-E (e-POP) RRI

Swarm-E RRI is a digital radio receiver with 4 3-m monopole antennas.  In most cases, the monopoles are electronically configured into a crossed-diople configuration.  In this configuration, RRI records I/Q samples for the two dipoles.  RRI has a sampling rate of 62500.33933 Hz, and a ~40 kHz bandpass, and can be tuned to anywhere between 10 Hz and 18 MHz.  More information on Swarm-E RRI can be found in the Swarm-E RRI instrument paper or Gareth Perry's recent Radio Science article.


  • Perry, G. W., Frissell, N. A., Miller, E. S., Moses, M., Shovkoplyas, A., Howarth, A. D., & Yau, A. W. (2018). Citizen radio science: An analysis of amateur radio transmissions with e-POP RRI. Radio Science, 53, 933– 947, https://doi.org/10.1029/2017RS006496.

Data Format

Each data file contains raw 32 bit complex I/Q samples for a given RRI dipole at a given frequency.  The samples are interleaved, e.g., IQIQIQIQ... The data files do not contain any metadata.  Any information regarding the time, frequency, and corresponding RRI dipole is in the file name.  

Filename Format

The filename format gives information about the time and data of the recording, the tuned frequency, and which of RRI's dipoles the recording corresponds too.  For example, gqrx_20150628_011614_3525000_62500_RRI_Dipole1 contains data recorded on Dipole 1, starting at 01:16:14 UT on June 28, 2015, at 3525000 Hz (3.525 MHz), at a sampling rate of 62500 Hz (RRI's 62500.33933 Hz sampling rate).


We have opted to convert the data into the .raw format so that it can be ingested into Gqrx.  There are other ways of analyzing RRI's data; this is just one way which we felt was as easy first step.  We are open to posting about other techniques on the HamSCI site as well.  To help get started with Gqrx, we have developed a How to play an RRI raw IQ file on Gqrx page.

Data Files

The data files may be downloaded directly from the Zenodo repository here


A call for abstracts is now open for the 2022 HamSCI Workshop, which will be hybrid in-person and virtual March 18-19, 2022 at The U.S. Space and Rocket Center Educators Training Facility in Huntsville, Alabama. Abstracts are due February 1, 2022. The primary objective of the HamSCI workshop is to bring together the amateur radio community and professional scientists. This year's theme is The Weather Connection, with invited speakers Dr. Tamitha Skov WX6SWW and Mr. Jim Bacon G3YLA presenting tutorials on the impacts of both space and terrestrial weather on the ionosphere, and a keynote presentation by Dr. Chen-Pang Yeang on Ham Radio and the Discovery of the Ionosphere. We welcome abstract submissions related to development of the Personal Space Weather Station, ionospheric science, atmospheric science, radio science, space weather, radio astronomy, and any science topic that can be related to space science and/or the amateur radio hobby.

In early 2022, there’s an opportunity for on-the-air camaraderie and friendly competition among HamSCI amateur radio operators:  HamSCI team entries in the January 2022 running of the North American QSO Party, SSB, better known by its acronym, NAQP. As the name of the contest implies, the focus is on North America, though DX stations are welcome to call in and make contacts. We propose having HamSCI team names such as HamSCI Grapes, HamSCI Tangerines, HamSCI Eclipse Watchers, and HamSCI SuperDARNs. Mark your calendars for Saturday, January 22, 2022, 1800z - 0600z, for some SSB, on-the-air, work-your-fellow-HamSCI-members kind of fun! Gary Mikitin, AF8A, has volunteered to organize and register the teams.  If you would like to participate, please contact him via <gmikitinaf8a> <at> gmail <dot> com.  Gary can answer any questions you might have about operating in the NAQP.

Our sense of sound can be a powerful tool in exploring and analysing data collected from satellites. But what is the best way to make this data audible? Space science researchers at Imperial College London are asking for input from communities with relevant expertise (including Audio, Citizen Science, Music, Public Engagement, and Science Communication) to help us choose the best method of making Ultra-Low Frequency waves around the Earth audible. Fill out our quick survey telling us which you think sounds best. It shouldn’t take more than 10 minutes. Your valuable feedback and recommendations will help space scientists around the world to improve science communication, public engagement, and citizen science.

If you would like further information please contact Dr Martin Archer, Stephen Hawking Fellow in Space Physics at Imperial College London via m.archer10@imperial.ac.uk. Thank you for your help!