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


Video recordings of the third annual HamSCI Workshop are now available through the Ham Radio 2.0 YouTube Channel. The 2020 HamSCI Workshop for amateur radio operators and professional scientists was held Friday and Saturday, March 20-21, 2020, virtually on Zoom at The University of Scranton. The theme of the workshop was “The Auroral Connection,” and included addresses by guest speakers, poster presentations, and demonstrations of relevant instrumentation and software.

By Carl Luetzelschwab K9LA

If you’ve come to https://k9la.us because of your interest in propagation, the following is a mini-guided tour to help you navigate to the material you’re interested in. The home page gives a basic introduction, and new items and relevant old items are listed here (usually at the beginning of each month). On the left side of the home page are links that contain material specific to certain aspects of propagation in our Amateur Radio hobby. The Monthly Feature link offers articles about a myriad of topics. These topics are often tied to observations of ionospheric propagation and measurements of solar and ionospheric data. Some important topics that have been covered are the new sunspot numbers (the April 2016 document), the ongoing study of gravity waves and travelling ionospheric disturbances (the March 2020 document) and a look at propagation on our 630-meter and 2200-meter bands (the December 2018 document). As a side note, many HamSCI participants are involved in the gravity wave/TIDs studies.

The 2020 HamSCI Workhop will go on! We are moving to an all-digital workshop using Zoom Webinar Services. Registration and participation is free and open to all. Exact details on how to register and participate will be posted to hamsci.org/hamsci2020 no later than Wednesday, March 18th. To prepare and make sure you are ready to participate in the 2020 HamSCI Workshop, please visit the Zoom Website and create free account.