Compass-2 labtests ©IZMIRAN

Compass-2 is expected to help make the first step in the practical forecasting of earthquakes from space. The 80 kg microsatellite was launched on May 26, 2006, 18:50 UTC, from the Russian strategic nuclear-powered submarine "Ekaterinburg" in the Barents Sea.

Radio Frequency Analyzer, FM-01 ©CBK/IRF

The Radio Frequency Analyzer (RFA) is an HF radio spectrometer that has been developed jointly by the Space Research Centre (CBK) of the Polish Academy of Sciences in Warsaw, Poland, and our group at IRF in Uppsala. The IRF contribution is the digital RX module that performs the raw frequency sweeps, which are processed and compressed onboard by the RFA computer before they are passed to telemetry.

The RX module samples the antenna using a 14 bit ADC with a sampling rate of 40 Msamples/s. A 19-pole antialiasing filter with a cut-off frequency at 18 MHz is used. The frequency sweeps are performed by a digital mixer with a software controlled numerical oscillator. A raw sweep contains 1024 frequencies with 16-bit complex amplitudes. Sweep data is compressed in three steps by the RFA computer. First the number of frequencies is decresed so that the frequency stepping is smaller for low frequencies and larger for high frequencies. Then the absolute value is taken, making data real valued. In the last step the logarithm is taken and the resolution adjusted to 8 bits.

• May 26, 2006, COMPASS-2 successfully launched into space

• Unfortunately, no data for six long months

• Nov 16, 2006, COMPASS-2 and RFA has come to life

• Nov 26, 2006, RFA switched on and first data received