December 2020 Eclipse Festival of Frequency Measurement

Alternate Language Options:
Spanish: Español
Portuguese: Portugués

Calling all stations: Join us for
The December 2020 Eclipse Festival of Frequency Measurement

9 December 2020 0000 to 16 December 2020 2359 UTC
 
 

Introduction

Changes in ionospheric electron density caused by space weather and diurnal solar changes are known to cause Doppler shifts on HF ray paths. For example, see Figure 7 in Boitman et al., 1999. HamSCI's first attempt at a measurement of these Doppler shifts was during the August 2017 total solar eclipse.  We plan a careful measurement during the 2024 eclipse. As part of the WWV centennial, 50 stations collected Doppler shift data for the original Festival of Frequency Measurement, demonstrating the value of volunteer participation in collecting this data. During the June 2020 Eclipse Festival, we enlisted participants around the globe and experimented with different data collection protocols.  This winter, we request that all amateur radio stations, shortwave listeners, and others capable of making high-quality HF frequency measurements help us collect frequency data for the December 14 total eclipse.
dopplercartoon.png
 

Contact information:

Kristina Collins: kd8oxt@case.edu

Research Questions

  • How do the propagation paths of shortwave time standard stations vary over a calendar day?
  • What properties of the ionosphere are we able to measure by observing the variation in these HF propagation paths?
  • What effect will the eclipse have on these propagation paths?
  • How do various measurement techniques for understanding the path variation compare?
  • Is there volunteer interest in collecting data in the regions near totality for this eclipse?

Objectives

  • Promote international goodwill by working with citizen scientists around the globe
  • Measure Doppler shifts caused by space weather's effects on the ionosphere.
  • Use a specified measurement protocol available to amateur radio operators and other citizen-scientists.

Times

  • Practice Runs: 21 November 20200000 – 2359 UTC, 5 December 2020, 0000 – 2359 UTC 
  • Data recording starts: 9 December 2020, 0000 UTC
  • Data recording ends: 16 December 2020,  2359 UTC
 

 

Please begin measurements before the day's start time and end them after the finish time, if possible.

The Beacons

 

There are multiple time standard stations which can be heard in South America. The Brazilian station PPE (10 MHz) will be the primary beacon for this experiment. You may also pick up signals from the Venezuelan station YVTO (5 MHz), the Argentinian station LOL (10 MHz), WWV, WWVH and BPM. This experiment will use only the 10 MHz transmissions. If you can't get a good signal on 10 MHz, record another frequency and make sure the file is labeled appropriately. The recordings in this experiment are expected to show formations of the D-layer at stations' local sunrise and other daily events of the ionosphere, and the effects of the eclipse. Space weather varies day to day and some features may be prominent.  We'll see what we get!

 

Procedures

 

1) Sign up on the Interest List

Fill out the survey here to sign up for the email list. You will receive occasional updates and reminders. 

2) Prepare Your Receiver

Use your most stable receiver. If you have a GPSDO or other precision frequency standard, please use it. 
 
To tune your radio:
  • Tune your radio (in AM mode) to the carrier signal.
  • Set your receiver's mode to USB (upper sideband). For a 10 MHz carrier, tune to 9.999 MHz (9999.000 kHz - see image) and listen for the 1000 Hz tone. This is the main thing we'll be looking for when we analyze your data. 
  • If you have an adjustable filter in your receiver, set it as close to 2.5 kHz as possible.

We will be advising most participants to use an 8kHz sampling rate in the section below. If your radio is relatively new (manufactured after the year 2000 or so) that should be just fine. If you're running an older radio, however, your filters may not have a sharp enough cutoff. (You can see this process in a video here.) To check the filter bandwidth on your receiver:

  • Tune your radio (in AM mode) to the carrier signal.
  • Set your receiver's mode to USB (upper sideband). For a 10 MHz carrier, tune to 9.999 MHz (9999.000 kHz - see image) and listen for the 1000 Hz tone. Tune down to 9.998 MHz and listen for the higher 2000 Hz tone. Finally, tune down to 9.997 MHz and see if you hear a 3000 Hz tone. If you don't hear a strong carrier signal, you're fine - stick with 8 kHz. If you do hear the tone, you may want to use a higher sampling frequency in Step 5 below. 22050 Hz is a pretty good bet. You can gauge the filesize for different settings here

3) Prepare Your Computer and Software

1) Connect your radio to your computer sound card. 
If you're controlling your radio via fldigi or flrig, you alreay know how to do this. Instructions will vary by radio. If you need a USB sound card, we recommend this one: https://www.amazon.com/gp/product/B00IRVQ0F8/ref=ppx_yo_dt_b_asin_title_...
 
2) Download Audacity. 
Audacity is a well-established open-source program for audio recording. You can download it here: https://www.audacityteam.org/download/
If you're working in a language other than English, you can set it using Edit > Preferences > Interface Options. 
 
3) Set up Audacity metadata. 
Download this XML template and make a note of the directory it downloads to: EclipseTags.xml
Under Edit>Metadata, click "Load" and select the file, then edit it to fit your station.. (You can also add metadata manually using the list below.)
 
 
In Audacity, go to Edit > Metadata and fill in the following metadata fields: 
  • Under Artist Name, put your callsign. (If you are a shortwave listener and not a ham, please use your name or SWL callsign.)
  • Under Album Title, put "December 2020 Eclipse."
  • Under Year, 2020.
  • Under Genre, put your radio model. 
Add and fill in the following metadata fields. 
  • Email Address
  • Rig
  • Antenna
  • Sound Card
  • Frequency
  • AGC (on or off)
  • Latitude (please use decimals, not minutes and seconds!)
  • Longitude 
  • Elevation (m)
  • Time zone (Format example: UTC-05:00)
  • Grid Square
  • Country

IMPORTANT: If you have multiple radios collecting data simultaneously under a single callsign, add a hyphen and station number for each station wherever you would otherwise use the callsign. For example, if station W8EDU is running data collection simultaneously on a Flex radio and an Icom radio, they should label one as W8EDU-1 and the other as W8EDU-2, include a comment in the metadata for each station explaining that the operator ran multiple stations, and make sure that the metadata is correct and complete. This will make it much easier to sort through the data from the experiment during the analysis phase. 

Hit "Save" and save the XML file, then hit "Set Default." 
Check the box that says "Don't show this when exporting audio," then hit "OK." 
 
 
4) Set recording preferences.
Open the Recording tab under the Preferences menu (Edit > Preferences > Recording). Uncheck "Play other tracks while recording" and check "Record on a new track" and "Detect dropouts." 
Under "Name newly recorded tracks," type your callsign, then a single underscore, then the letter corresponding to your time zone on this list: [https://en.wikipedia.org/wiki/List_of_military_time_zones]
For example, the station W8EDU is in Eastern Standard Time (UTC - 05:00), which corresponds to the letter R, so the correct custom track name is "W8EDU_R_". (If you're in a fractional timezone, use the letter J.) 
 
Make sure the boxes for "System Date" and "System Time" are also checked. When you're done, the window should look like this: 
 
Under "Quality," set "Default Sample Format" to 16 bits. Set "Default Sample Rate" to 8000 Hz (unless your receiver requires a higher rate, as described in Step 2 above).  
 
Go to "Devices" in the Preferences menu and make sure you are recording from your radio, as opposed to your computer's microphone or another source. 
 
When done, click OK.
 
5) Set recording settings and make a test recording.
Set your recording to Mono (1 channel) on the pulldown menu in the middle of the top toolbar.
 
Make sure your project rate is set to 8000 Hz from the pulldown menu in the bottom left corner of the screen.
 
Set your audio input to the sound card connected to your radio. The device names will vary. You may have to experiment to make sure the source you're recording from is the correct one.
 
Hit the record  button; you should see the first track start recording, with the correct track name and timestamp. If the track name is not correct, try rebooting your computer and recording again.
Hit stop ⏹️, then record  again. This time, you should see a second track appear. The name on each track will correspond to its start time. 
 
Note the "Disk space remaining for recording" at the bottom of your screen. One week of recording is 168 hours, so you may need to pause and restart data collection during the experiment. The estimate also may not be entirely accurate. Check Audacity's documentation on recording length here
 
6) Save the project.
Make sure to stop ⏹️ the recording before you continue.
Save the project (File > Save). This will let the computer hang on to your settings. You may see a window asking if you want to save the project even though it has no tracks in it: click OK. 
 
7) Check to make sure your WAV files save correctly.
Create a directory to save your files to according to the following convention: "<Callsign>_Eclipse_Dec2020". For example: W8EDU_Eclipse_Dec2020. (If you're running simultaneous data collection on multiple radios, use the hyphenated identifier described in Step 3.)
 
Go to File > Export > Export Multiple. Select the directory that you want to save your files to. Under "Name Files", make sure the option "Using Label/Track Name" is selected.
 
Click "Export." You should get a dialogue box confirming that each track has been saved to its own WAV file. (Note: If your files are too large to export, see the FAQ below.)
When these are done, you can delete your test tracks by clicking the X in the upper left hand corner of the track. 
 
When you open the directory, you should see the artist and album metadata. Confirm that your filenames are in the correct format: "W8EDU_R__2020-10-23_22-36-18.wav"., for example. 
 
You should record your data on a drive that has at least 10 GB of free space. If you are running Windows, navigate to your data directory and activate compression:  Properties -> General -> Advanced  -> Compress contents to save disk space. (See screen shot below).
 
 
8) Optional: Calibrate Audio Output for the .WAV File Record
We're interested in collecting amplitude data where possible; you can read more about it here. If your radio has an automatic gain control (AGC) circuit that can be disabled, and a separate RF gain control, you can also collect amplitude data. It's not enough to just turn the AGC off, though; you have to set the RF gain to an appropriate level.  Otherwise the audio level will be nearly a constant level regardless of the signal strength, and the data may be compromised. Once the AGC is turned OFF the receiver’s RF gain control must be set so that the audio  level gives measurable amplitudes that never go full scale, clip, or limit. This will require preliminary testing to be sure the maximum signal strength does not overdrive the sound card input. If your radio does not fit these requirements, skip to Step 9 below. 
 
Here is a method to set up the receiver:
  • With AGC enabled, set up the radio to produce the 1000 Hz tone in USB mode by tuning the radio 1 kHz below the carrier frequency (e.g., 9.999 MHz for a 10 MHz carrier).
  • Set the receiver volume control for a comfortable listening level using the radio’s normal speaker or headphones. It should be loud enough to be above the no-signal receiver noise but not so lout that it causes distortion.
  • Set the recording level in Audacity to get approximately 1/4-1/2 full scale recording level, or at the level that leaves about 6 dB to 10 dB of headroom below full scale.
  • Turn the receiver AGC OFF.
  • Use the RF gain control to set the audio output to the same level as with the AGC ON.
  • Make a day-long recording and examine the record. If the levels reached full scale at any time during the recording, reduce the RF gain control and try again. The idea is to have enough RF gain get measurable signal levels even during the weakest part of the day but not so much that the amplitude at the strongest part of the day hits or flattops at full scale. 
  • Once the RF gain is set it must not be changed while recording eclipse data.
  • When submitting your data survey below, make sure to confirm that you performed this procedure. 
9) All set!
Now you should be all set to collect data! If you need to restart data collection at any time, hit the stop recording button and repeat Step 7 above. 

Once you're all set, your setup should look something like this:

3) Collect the data

The data collection runs from 9 to 16 December. There will also be two practice runs: November 15th and December 5th. During this time, leave your radio running, check it periodically and make sure your computer is not shut down by an automatic update. 
We strongly recommend recording a few days' worth of test data before the experiment begins in order to ensure that you don't run into computer problems. After completion but before uploading, select the file/directory to  be uploaded, right click on it, and select Send to compressed (zipped) folder.  This is what you should upload.

If you would like to include documentation of your station, notes on observations, photos of the experiment or eclipse, etc., please include these in the zipped folder with your data. Unless you note otherwise, we may use your photos, with attribution, in future HamSCI materials. 

 

4) Fill out data collection survey and upload data via Box.

Fill out the data collection survey here. (This is only necessary for the main data run, not the practice runs.)

Upload your at this link: https://cwru.app.box.com/f/d707e6414087462399f3601a2a4e0ca0

You can upload as many files as necessary, but each individual file should not be larger than 15 GB. Compressing your files may help reduce your upload speed. Note that wav files will usually only shrink to about 80% of their original size. You should NOT use mp3 or wma compression, because these formats can compromise amplitude and frequency characteristics.

 

Frequently Asked Questions

Q: What will this data be used for?
A: This data will be analyzed by members of the HamSCI organization. The data and results will be made public, as we did for the orignal Festival of Frequency Measurement.
 
Q: I'm not inside the path of totality. Can I still participate?
A: Absolutely. Gathering data from widely scattered stations lets us examine ionospheric fluctuations on a range of scales. We're aiming to get stations on every continent. 
Wherever you are, however, the best approach is to get one or two friends with stations nearby to participate, to confirm that the fluctuations in your data are geophysical in nature.
 
Q: I missed the practice run. Can I still participate?
A: Yes! Get in touch via email if you have questions.
 
Q: Can I join in late?
A: Yes! Get in touch via email if you have questions.
 
Q: If I'm having trouble getting data collection to work, can you help me?
A: Yes. Email hamsci@case.edu and we will help you get your radio set up.
 
Q: Can I use a program other than Audacity to make my measurements?
A: Yes, but we cannot provide assistance for other programs. We also like Spectrum Lab, though.
 
Q: Why did you stop using fldigi?
A: We've used fldigi's Frequency Analysis mode in past experiments, but we've decided to collect raw data for this one because it will let us collect sideband as well as carrier information. 
 
Q: How can I check the metadata on my WAV files?
A: Most metadata tools won't show the nonstandard fields that we added, but you can use mediainfo if you want to see them. It has a nice command line interface, too. 
 
Q: Why do you want to collect an entire week of data? Doesn't the eclipse only last for a few hours?
A: We need to collect control data, ideally from a day with ionospheric conditions that are as similar as possible to the conditions on the day of the eclipse. Collecting a full week of data gives us a few options for that comparison. It also gives us a good look at daily fluctuations. 
 
Q: Can you still use my data if I can't record for the entire period?
A: More data is always better, but if you need to take your radio back for part of the event (e.g., to run a traffic net) or experience a data interruption, then we're still interested in your data. Just be sure to stop recording before retuning your radio, tune back to 9.999 MHz before you start it up again when you're ready to resume collecting data, and leave us a note when you submit it.
 
Q: Will you accept other forms of data?
A: Yes, although we can't guarantee we'll be able to use it. 
 
Q: I can collect data for the experiment, but my Internet connection is so slow there's no way I'll be able to upload it to you. Can I submit it another way?
A: Yes! Email me at kd8oxt@case.edu and I'll mail you a thumb drive. 
 
Q: Audacity says my recording is too large to export as a WAV file. Why is this happening, and what can I do?
A: WAV files are limited to 4 GB because the filesize is indicated in the header by a 32-bit unsigned int. Audacity will give you another chance to export. Select "Other uncompressed files," then under "Header," select "WAV(NIST/Sphere)." This will use a different header format, but your data should be the same, and can be uploaded as long as it is less than 32 GB. 
 
Q: I'm able to set up a station to collect data long-term. Would you be interested in that?
A: Yes! Email hamsci@case.edu to discuss further.
 
Q: Will I receive a QSL card?
A: Of course! Eclipse Festival certificates will be mailed to all participants at the conclusion of the analysis.

 

 

Media Mentions

https://www.ce3aa.cl/el-festival-eclipse-de-medicion-de-frecuencia-de-di...

https://cqnewsroom.blogspot.com/2020/11/volunteers-needed-for-propagatio...

https://www.arnewsline.org/news/2020/11/19/amateur-radio-newsline-report...

https://www.spreaker.com/user/hamtalklive/episode-237-q-a-with-rob-sherw...

http://www.arrl.org/contest-update-issues?issue=2020-11-25

https://youtu.be/YX-vTKt1LGk?t=1626

https://www.iaru-r2.org/en/opportunity-to-participate-in-eclipse-propagation-experiment/

https://hackaday.com/2020/11/30/gathering-eclipse-data-via-ham-radio/

Lunchtime Livestream for December 2 - Ham Radio Livestream - YouTube

Acknowledgments

Thanks to Matt KE8NZR for Spanish translation and Noilson Caio - Darkwaves group for Portuguese translation.