Measuring propagation delay with WSPR?

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Measuring propagation delay with WSPR?

I am writing to this forum because in Italy the use of 70 MHz band will be granted again, even if only for the 1 February 2012 - 31 December 2012 period. This because, on behalf of my University (Univ. of L'Aquila), I have issued a request to the Italian Frequency Allocation Office (see

I am planning to run some experiments with my students and we will use WSPR to test Transequatorial Propagation paths on 70 MHz. It should be very interesting to measure the propagation delay between TX and RX stations. This measurement will allow to estimate the geometry of the duct within the ionosphere. By the way, some papers refers to a duct located at an height of 850 km, which is a rather large value for ionosphere.

Let's assume that both TX and RX station will be equipped with a GPS receiver giving the Pulse-Per-Second (PPS) signal. Do you think that an enhanced version of WSPR could be able to measure the propagation delay with an accuracy of about 0.5 ms or better? Could an enhanced version of WSPR get the PPS signal using one of the two audio signal inputs, in order to bypass the perhaps unpredictable jitter in PC clock in the case the PPS were used to synchronize PC clock?

Don't you think that such a feature in WSPR could be useful also in retrieving path information even in more usual contacts, e.g. via F-layer. In other words this feature could allow a sort of bistatic sounding of the ionosphere, at least in order to measure the virtual height of the reflecting layer.

Let me know what do you think about this idea and if someone can develop such an enhanced version of WSPR.

Bets regards.
73 de I0KPT, Piero