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Thoughts on WSPR and propagation monitoring

Hi All,

I've been thinking about the recent threads WRT receiver performance, propagation monitoring, WSPR monitoring, choosing the best on-line SDR for a particular frequency and region etc.

WSPR has a number of interesting features. It sends data in each transmission which indicates the individual stations transmit power and location. The receiving station calculates the S/N ratio of each station heard and uploads this information to the WSPR.NET website along with the transmitting stations call sign, transmit power and location.

WSPR also has the option to scan various bands in a pre-defined sequence which some stations use - the following is from WSPR documentation.

"WSPR includes a "Coordinated hopping" mode in which the selected band is determined by the starting UTC minute of a Tx/Rx interval:

UTC Band
Minute (m)
00 160
02 80
04 60
06 40
08 30
10 20
12 17
14 15
16 12
18 10

20 160
22 80
... etc

This sequence of ten possible bands repeats three times each hour. If the designated band has not been checked as an active band, a random choice is made among the active bands."

Thoughts / ideas for further discussion:-

Could an additional "Coordinated hopping"  option be added to the existing WSPR extension so that more than one WSPR band could be automatically covered by a single KiWi receiver ?

Could each KiWi running the WSPR extension build up a list of stations heard including for each one frequency (band) / locator / transmit power and received S/N. This data could then be processed and the S/N value adjusted to a normalised value by taking into account the transmitter power in use. 

The data gathered (as above) could then be processed either on the KiWi (if it is capable) or on a centralised website to give an indication of propagation on each frequency, distance, bearing and normalised S/N value. These parameters could then be used to produce a real time propagation map for each SDR.

In order to reduce the amount of processing required maybe just a few 'known good' WSPR beacon stations in each region could be used, rather than having to process lots of stations who only transmit occasionally. This data could perhaps be dynamically populated from the usage stats on the WSPR.NET site. 

Obviously this would work a lot better if WSPR could run as a background task on each SDR when there was a spare receiver slot available (as previously discussed at some length), but even in it's basic form I think it could provide some useful data.



Martin - G8JNJ


  • Some of this information may already be available. A couple of Kiwis are compared:

    So if WSPR can be run when slots are empty, the data would already be gathered when the WSPR reports are sent. Then it is a question of doing something with all the data.

  • I still long for local wspr control via a ssh login that could run in the background 
  • edited October 2017
    I have been thinking about the coordinated hopping to monitor WSPR on multiple bands with one receiver instance. A look at the WSPR database indicates that a few (but not many) stations are transmitting on the schedule. Even so, it would be useful to monitor multiple bands even if not coordinated.

    But, as far as I can tell, the implementation of WSPR seems to make that difficult. Changing the band seems to stop the decoding of the previous band. Waiting for the decoding to end leaves the receiver in sync mode for most of the next 2 minutes.

    So, hopping once every 2 minutes and decoding and uploading the results looks problematic.

    This is just from looking from the outside - I haven't delved into the code. Does someone know more?

    I also vote for a headless WSPR mode that runs without an open web browser UI.

  • The KiwiSDR will open a WSPR instance in each slice, so you can have 4 simultaneous instances of WSPR running on one KiwiSDR. The sound can be muted and WSPR will continue to receive stations. It does tend to occupy all the resources on a given KiwiSDR to do this though.
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