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.

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


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!

The 40th annual ARRL and TAPR Digital Communications Conference (DCC) will take place September 17–18, 2021. Due to the coronavirus pandemic, this year’s conference will be held online. Registered DCC attendees participating via Zoom will be able to interact with presenters and other attendees via a chat room as well as raise a virtual hand to ask questions. Click here to register (you don’t need a Zoom account to register). Non-registered DCC attendees can watch the live stream for free on YouTube and can chat and ask questions via the moderator monitoring the channel. No registration is required for YouTube access (the YouTube URL will be announced and posted on this webpage preceding the DCC). DCC registration is free for TAPR members and $30 for non-members. Members receive a 100% discount at checkout. Click here to register. Non-members who would like to join TAPR and receive the free DCC pass can simply add TAPR membership and DCC registration to their shopping carts. After checkout, they will receive the free DCC pass when their membership is processed.

Call for Papers and Speakers: Technical papers are being solicited for presentation. Papers will also be published in the Conference Proceedings. Authors do not need to participate in the conference to have their papers included in the Proceedings. The submission deadline is August 15, 2020. Submit papers via email to Maty Weinberg, KB1EIB, maty@arrl.org. Papers will be published exactly as submitted, and authors will retain all rights.

HamSCI's Kristina Collins KD8OXT, a PhD student a Case Western Reserve University, was interviewed by Steve Ford WB8IMY in the March 11, 2021 epsiode of ARRL's Ecletic Tech podcast. In the podcast, Kristina talks about the upcoming 2021 HamSCI Workshop, the Grape Personal Space Weather Station, and the Festivals of Frequency Measurement. The Festivals of Frequency Measurement are large-scale experiments to observe ionospheric and propagation variablity by measuring small Doppler shifts in signals received from standards stations such as NIST's WWV. Kristina's recently published a feature article on the HamSCI work in the American Geophysical Union's EOS magazine and initial results of the 2019 WWV Centenial Festival of Frequency Measurement in IEEE Geoscience and Remote Sensing Letters. Great job, Kristina!

Click here to listen to the podcast.