Theoretical and experimental study of Poseidon altimeter acquisition phase

The altimeter system is based on a 900 MHz frequency ramp at 13.65 GHz band, the ramp length being 10 micro sec. Heterodyning the signal and the echo gives a frequency proportional to the distance. Pursuit algorithms are used to estimate the altitude. A breadboard model of the hardware was used in the performance tests. The results are in agreement with the theory and the simulations. Acceptable values are obtained at signal to noise ratios of 3 dB.