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


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.

Registration is now open for the 2021 HamSCI workshop. A full schedule of speakers and registration information can be found on the HamSCI Workshop 2021 website. The workshop will be held in a virtual format on Friday and Saturday, March 19-20. The University of Scranton will serve as host for the Zoom webinar, sponsored by the National Science Foundation (NSF), that will include addresses by guest speakers, poster presentations and demonstrations of relevant instrumentation and software. The theme of this year’s workshop is midlatitude ionospheric science. The workshop will also serve as a team meeting for the HamSCI Personal Space Weather Station project, which is a NSF funded project awarded to University of Scranton physics and electrical engineering professor Nathaniel Frissell, Ph.D. The project seeks to harness the power of a network of licensed amateur radio operators to better understand and measure the effects of weather in the upper levels of Earth’s atmosphere.

The annual HamSCI Workshop will be held virtually this year March 19-20, 2021 using Zoom hosted by The University of Scranton and sponsored by the National Science Foundation. The primary objective of the HamSCI workshop is to bring together the amateur radio community and professional scientists. The theme of the 2021 HamSCI Workshop is midlatitude ionospheric science. We welcome 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 appropriately related to the amateur radio hobby. We especially encourage subimissions related to this year's meeting theme of midlatitude ionospheric physics, but will also accept abstracts outside of this theme and otherwise appropriate. To submit an abstract, please fill out the on the HamSCI Workshop 2021 page at http://hamsci.org/hamsci2021.