56.5°E Inmarsat-5 F4 or 56.8°E WGS-8

I am not sure if these signals are from Inmarsat or WGS-8 at 56.8E. There is only 0.5 degree between them from my location. There are 2 carriers, spaced at 1MHz, on 20201 and 20202MHz and a 32APSK signal, unlocked, on 20506 MHz, 32APSK, 9000, 3/4. The carriers are only 22dB C/N in 50Hz so are hard to find without an analyser. The APSK signal is well below threshold with me. All are circular polarised and were received on a linear feed.

I can not see the 20680 signal but the LNB has rolled off a long way by there.

Can anyone else get a better fix on them?

Zitat

Original von hvdh
Thanks for finding this, be it Inmarsat-5 F4 or WGS-8, that both arrived recently here. In any case, worth a new topic!
I suppose there is nothing below 20.2 GHz that would be Inmarsat only.
Surely the correct satellite will be identified sooner or later.

Thanks, hvdh. I cannot see the beacons that are supposed to be on Inmarsat. However, I left the dish pointing at that location and a strange signal has appeared on 19600MHz circular. There is a strong carrier with sidebands spaced at about 78.6kHz that spread +/-25MHz. The SDR only has a span of 5 MHz and the analyser does not have enough resolution so I can't show the whole thing. It can be seen on Crazyscan but makes less sense there.

As far as I can tell the new one peaks at the same point as the beacons.

Zitat

Original von hvdh
Great! The Inmarsat-5 frequency plan lists 19600 as 32 MHz gateway transponders, both LHCP and RHCP.
http://frequencyplansatellites…g/Inmarsat/Inmarsat_5.pdf

Interesting. I am still confused as I can't work out what the data format is since I can't see any actual data. The comb is static.

There's another Ka satellite 2 degrees west and 1 degree north of this one. It has a CW beacon at 20202.5 (needs checking) and the wide band data as attached. Expres-AM6?

I tried again with the circular polariser. It was very confusing as the satellites share frequencies but on opposite polarisations. All beacons appear to be CW only.

Listed are my guesses at the satellites and their beacons. The Az-El values do not have good absolute accuracy but have reasonable relative accuracy, at least to the extent that I have the satellites in the correct position order.

hvdh, do you find it believable?