[Scan-DC] Greenbelt DORIS

[David L. Wilson]

The big news is that I can hand decode the audio file by looking at it 
in Audacity! It took time to figure out how but I can now do it. I have 
experience doing things like that as I have similarly reverse engineered 
institutional (schools, hospitals, etc.) Prime Wireless (frequencies in 
72-73 MHz), Innovation Wireless time synchronization transmissions 
(usually 467.2125 MHz), INMARSAT D+/Isat M2M (I had no info on that 
system at all and it took 2 years of spare time to figure out), and 
other modes in HF.  I will write that up how to do hand decoding of of 
the DORIS beacon and post it in a day or two...that will show the 
Greenbelt DORIS beacon ID.

Ignore the postings I made about 12.5 and 14.2 Hz in connection with 
DORIS.  They were a sampling artifact of my reception that I have now 
remedied.

Note that I now know the data bursts on 401.25 and 2026.25 MHz are *not* 
identical.  Although they sound the same to the ear, the bursts are 
every 10 seconds on each frequency but the burst length on 401.25 MHz is 
1 second with the burst on 2036.25 being 1.32 seconds.  I have confirmed 
this in documents and by measurement.

Also, the "39" ID for Greenbelt is its DORIS RINEX ID but not the beacon 
ID.  That will be in my future post showing how to hand decode DORIS 
from an audio file (as it will take a little time to write pu).

-- 
David L. Wilson