2017 Eclipse HF Wideband Recording Experiment

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Total solar eclipses are known to cause changes to the ionosphere and high frequency propagation. During the 2017 American Total Solar Eclipse, numerous HF radio sources will be on the air to help study these effects. We request that amateur radio stations capable of making wideband (e.g., 192k or higher sample rate) digital HF recordings participate in this experiment and publish their data to the HamSCI community on the open-data sharing site zenodo.org.
 
Research Question
  • How does the 2017 Total Solar Eclipse affect HF propagation paths?
  • How much of the ionosphere is affected by a solar eclipse?
  • For how long is the ionosphere affected by a solar eclipse?

Objective

  • Observe changes in HF propagation caused by the eclipse by making recordings of large portions of the HF band from multiple locations, most importantly across the North American continent.
  • Provide wideband recordings of HF spectra to support SEQP log/RBN/PSKReporter/WSPR data.

Times

  • 21 August 2017, 1400 – 2200 UTC
Note: Partial eclipse begins 21 Aug 2017 at about 1600 UTC in Oregon ends at 21 Aug 2017 at about 2015 UTC in South Carolina.

Frequencies

Please prioritize recording of frequencies that correspond with Solar Eclipse QSO Party (SEQP) operation, especially the lower frequencies, as these should see the largest eclipse effect. This consists of the standard HF contest bands (see table below). In addition, we welcome observations from as much of the LF, MF, and HF spectrum as possible. The capabilities of different HF receivers vary widely, and some modern HF SDRs are capable of multiple slice receivers. Note that it is possible to simultaneously make wideband recordings and act as a RBN skimmer node. See N6TV's How-To Guide for Running a Combined CW-RTTY Red Pitaya Skimmer for instructions on how send SDR data streams to multiple programs simultaneously.

Solar Eclipse QSO Party (SEQP) Frequencies
Band Frequency
160 m 1.800 - 2.000 MHz
80 m 3.500 - 4.000 MHz
40 m 7.000 - 7.300 MHz
20 m 14.000 - 14.350 MHz
15 m 21.000 - 21.450 MHz
10 m 28.000 - 29.700 MHz

Procedure

You may use any radio and software that is capable of generating IQ recordings of HF spectrum that can be properly time-stamped and frequency-stamped. We recommend using MIT Haystack's Digital RF software for this purpose, as it is will record observations to the proper IQ format and provide the required time- and frequency- stamping.

A number of SDR radio and software combinations allow real-time wideband recording of the HF spectrum.  The spectrum width that can be recorded is usually a bit less than the radio sample rate.  For example, a 384k sample-per-second receiver can record around 375 kHz of bandwidth, which is enough to include the entire 40, 30, or 20M band.  A number of SDR receivers, including RTL-SDR "dongles", Red Pitaya, and "HPSDR" compatible radios such as the Anan 10/100/200 series and the original Hermes board, are capable of this.

An Open Source Software script using GNU Radio under Linux will shortly be available through TAPR that allows receiving and recording four bands simultaneously with HPSDR or six with the Red Pitaya hardware.  (Note that multiple receivers will require a fairly fast PC such as an i7 with solid-state disk; using fewer receivers reduces the computer resources needed.  Check https://github.com/TAPR for updates.

We encourage you to make the most careful measurements possible. If you are capable of stabilizing your receiver with a high-stability frequency reference or provide amplitude calibration characteristics for your system, please do so. You may describe your methodology in the Zenodo Data Description box and upload supporting documents if necessary (such as block or antenna pattern diagrams).

Uploading to Zenodo

We ask that all data generated by this experiment be uploaded to the HamSCI community on zenodo.org. By uploading to zenodo.org, a permanent, citable, centralized record of the data that is openly available to both researchers and the general public will be created. 
 
To upload your data create an account on https://zenodo.org. You can create a login using your github account or via their account creation. Once you have an account and you are logged into the service visit “https://zenodo.org/deposit/new?c=hamsci”. Select your file(s), click “Start Upload”, select “Dataset” as your upload type, fill in all relevant information regarding contributors, and finally click "Save" and then “Publish” in the bottom right.

Data Files

Please submit the following items:

  • IQ File for each band recorded (Will be encapsulated in a HDF5 file if using MIT's Digital RF)
  • Supporting data files (i.e. any files needed to help interpret the raw data, such as a block diagram of the receive station)

Use the <Callsign>_wideband_<start_freq>_<stop_freq>kHz_<YYYYMMDD>_<HHMM>UT.<ext> filename convention for uploaded where HHMM is the UT start time of that particular file. Examples:

  • K2MFF_wideband_3500_3692kHz_20170821_1400UT.hd5 (for a HDF5 IQ recording  of 3500-3692 kHz made at K2MFF on 21 Aug 2017 starting at 1400 UT)
  • K2MFF_wideband_supporting_20170821_1400UT.pdf (for a PDF of supporting material to help in interpreting the data)

Data Description

In the data description box, please include:

  • Your Name and Call Sign
  • Latitude and Longitude of the Recording(s)
  • A description of station hardware configuration, including
    • Antenna type
    • Antenna pointing direction (if applicable)
    • Receiver type
  • Any other information you believe would be necessary for proper scientific interpretation of your measurements

Data Notes

In the Notes box, you may include your personal comments regarding your observations.

Too Much Data?

Zenodo accepts up to 50 GB per data set. If necessary, please upload each band recording as a separate dataset. If this method is not feasible, please contact hamsci@hamsci.org and we will find another way to transfer the data.

Data License

Please license your data as:

  • Open Source
  • Creative Commons Attribution 4.0

Thanks!

Thank your for your time and effort in participating in this experiement!

Page Contributors: W2NAF, N8UR

Last Edited: 15 August 2017