[amsat-bb] FM signal on FO-29?

Daniel Estévez daniel at destevez.net
Mon Nov 9 20:29:12 UTC 2015

Dear Bob and Zach,

This paper might be worth looking at:

As far as I know, it started the whole business of location by
measurement of Doppler shift.

Apparently, according to the success of project Transit, it is possible to:

a) Compute the TLEs of a satellite by using just a few minutes of the
Doppler curve of the beacon of a satellite, as received on a ground
station with known location.

b) Compute the location of a ground station, by using just a few minutes
of the Doppler curve of the beacon of a satellite with known TLEs, as
received on said ground station.

Of course, several variation on this are possible, such as the one which
is discussed here:

Compute the location of a ground station by using the Doppler curve of
its transmissions during a pass, as received on a satellite with known TLEs.

It seems that the key point in all this is that the Doopler curve
depends independently on all the parameters in question (so not a cubic
polynomial, which depends on fewer parameters).



El 09/11/15 a las 17:59, Zach Leffke escribió:
> No worries, I thought on it a bit more and I think a cubic polynomial is
> the right fit.  I also found some python tools for regression
> calculations that I think will be useful for this.  Also, I think this
> is pretty similar to how the COSPAS/SARSAT system used to locate lost
> ships (EPIRBs) and downed Aircraft (ELTs) before the proliferation of
> GPS and its inclusion in the locator beacons.

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