Various satellite tracking results using a Software-Defined Receiver

Sven Grahn


USA-198 was launched as NROL-24 from Cape Canaveral by an Atlas rocket at 2205 UT on 10 December 2007. Reception in Stockholm 22 minutes after launch as per the spectrogram below.


Progress-M62 on 121.75 MHz, December 26, 2007, 0816 UT

The spectrum below probably shows the TORU remote-control link between the ISS and the approach Progress. The signal appears on the standard Soyuz voice frequency. In the spectrum below there is clearly a Doppler shift.

Progress-M62 on 166.0 MHz, December 26, 2007, 0951.00-0954.50 UT

Here the two spectrum peaks about +/- 128 kHz from the center frequency can be clearly seen. One can also see the horrible interference environment at this frequency with taxi dispatch radios and their data bursts. Despite this, the signals from the spacecraft come through clearly. The Progress had docked with ISS at 0811 UT. The antenna used to receive this was a discone.

Progress-M62 on 166.0 MHz, December 26, 2007, 1125.50-1128.30 UT - command-on

In the spectrum below command-on of this telemetry signal can be seen. The spacecraft was due south of Stockholm at command-on. The signal is very strong.

Progress-M63 on 166.0 MHz, February 6, 2008, 1733.45-1738.30 UT

In the spectrum below command-on of this telemetry signal can be seen. It looks  a little bit different from that of Progress-M62. There are no sharp peaks at +/-128 kHz!. The "bumps" seems flatter and smoother than before.


Russian Navsat Kosmos 2429 on 150.03 MHz

The +/- 3 kHz and +/- 5 kHz subcarriers carry the data while the +/-7 kHz subcarriers provide 1 second timing pulses. What the +/-10 kHz subcarriers are for I do not know. The Doppler shift is inverted because the AR8600 receiver has an inverted intermediate frequency at frequencies below about 1 GHz (the limit could be 1040 MHz or 2040 MHz where the receiver switches circuitry).

Soyuz-TMA13, 12 October 2008 on 121.75 MHz


Soyuz-TMA13, 12 October 2008 on 166.0 MHz

Progress M-01M, 26 November 2008 on 166.0 MHz, 1843.53-1846.18 UT

Certainly looks similar to Progress M-63 and not Soyuz!

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