Re: [dxsoft] mode suggestion
Henrik,
I believe only the Wavecom decoders for government use can decode GW Pactor
itself.
The channel free markers which can be decoded by Hoka and Skysweeper are not
really very interesting - mainly because all they have is a single byte ID
and no-one has properly correlated these to known coast stations.
Here is all I have on it if anyone is interested in taking it further:
Globe Wireless Marker Decoding
==============================
Globe Wireless provides HF marine traffic via coast stations.
They use a proprietary modem which sounds similar to Pactor.
Protocol Description
Unfortunately, the protocol they use on HF is a proprietary one for which
few decoders are available. The signal uses at least two different
modulations: 100 baud, 200Hz shift synchronous FSK and PSK.
Globe Wireless seems to send at least 4 distinct kinds of traffic from their
stations:
*Channel Free Marker
ARQ Data (speculative)
Selcall or FSK data (speculative)
PSK data
*Decoding the Channel Free Marker
There is a repetitive channel free marker broadcast when a channel is idle.
This is in 100bd 200Hz shift FSK.
The total number of bits sent in the channel free marker is 231.
The first 98 bits compose this header:
10100101001000000011100010100011000111110110110000110101001110110100101111110010\
111100101111001011
Following this, an 8 bit quantity repeats 6 times - a form of FEC.
The byte corresponds to the following table:
0x47 HLF, Seoul, South Korea
0x49 KEM, Nikolski, Alaska, USA
0x4e VCS, Halifax, Nova Scotia, Canada / VCT, St. Johns, Newfoundland,
Canada
0x5d KEJ, Honolulu, Hawaii, USA
0x5e CPK, Santa Cruz, Bolivia / VCT, St. Johns, Newfoundland, Canada
0x5f A9M, Hamala, Bahrain
0x63 9HD, Malta
0xc3 XSV, Tianjin, China
0xc9 VIE, Darwin, Australia / ZLA, Awanui, New Zealand
0xcc HEC, Bern, Switzerland / 9MG, Penang, Malaysia / LFI, Rogaland, Norway
0xd2 ZSC, Capetown, South Africa
0xd7 KPH, San Francisco Radio, San Francisco, California, USA / VJS, Perth,
Australia
0xd8 WNU, Slidell Radio, New Orleans, Louisiana, USA
0xdb KHF, Agana, Guam
0xdc KFS, Palo Alto, California, USA
0xdd LSD836, Buenos Aires, Argentina
0xde SAB, Goeteborg, Sweden
0xe3 8PO, Bridgetown, Barbados
There are other stations with unknown bytes.
E.g., 0x3b possibly Pt. Reyes, California, USA.
More work is needed to match all the coast stations.
Credit to Ben Mesander
http://tiki-lounge.com/~ben/radio/gw.html