S-band testing on station 39

Today, @pierros and I ran some tests of the satnogs software on S-band. Using my 3.5 turn helix onmi-directional antenna, G4DDK LNA and Ettus B200 we tracked the TT&C beacons of some of the satellites in the Cartosat constellation.

Observation https://network.satnogs.org/observations/113943/ shows the TT&C beacon without Doppler correction, with the central signal the DC peak of the SDR.

These satellites tend to ground lock with the ground station in Svalbard, so it took us some time to figure out what we were seeing. Observation https://network.satnogs.org/observations/114223/ shows the TT&C beacon steady for the first 400 seconds as it rises in the South (from the Netherlands), and then gets in range to Svalbard and jumps to +40kHz. The TT&C beacon to the left is that of CARTOSAT 2F [43111/18004A], of which the data sidebands are visible.

It looks like S-band works out of the box with the satnogs software, but probably a directional helix or dish will be required to demodulate/decode signals.


Isn’t the other NOAA downlinks in S-band?

You mean the HRPT transmissions? They’re at 1.61 to 1.71GHz, so a bit lower. Between 2.2 and 2.3GHz on S-band there’s lots of TT&C beacons, and some data transmissions.

Just looked it up they are in the L band

Wow impressive with just a 3turn helix. As soon as I have my g5500 running again I will for sure try and track a few Sband birds using a 60 or 90cm dish and downconverter.

Great work you guys.

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