[Scan-DC] 401.25 MHz DORIS beacon coming from Goddard or somewhere else?

[Andrew Clegg]

Hi all,

I notice a beacon on 401.25 MHz that, based on its characteristics, seems to be part of the DORIS system<http://www.sirgas.org/fileadmin/docs/GGRF_Wksp/26_Soudarin_et_al_2019_DORIS_and_IDS.pdf> of ground-based beacons that help satellites in orbit determine their position to very high accuracy. It's sort of a reverse GPS (ground-to-space). The beacon is a CW tone, with a 0.8 second data burst every ten seconds, at 1 second before each ten seconds (i.e., 9 seconds, 19 seconds, 29 seconds, etc., past the minute).

I am in Arlington and the closest official DORIS tx site I see listed is at Goddard. Seems kind of far away for me to be hearing it pretty clearly in Arlington, especially if it's designed to point up.

Is anyone located near Goddard and could see if there is a signal that fits this description that's very strong there? Or do other people hear this in areas that are not near Goddard? I think you'd need a receiver that can do CW or SSB mode to be able to hear it.

DORIS also transmits on 2036.25 MHz but I can't hear that here, although I do hear a constant weak CW tone about 10 kHz off that frequency, but no data burst.

(Apologies if this is too wonky, but I think it's cool finding exotic signals on the airwaves!)

73,
Andy
W4JE