Correlation properties of ocean altimeter returns

The correlation properties of altimeter returns are useful in the optimal design of altimeter systems. They are also necessary for implementing maximum likelihood estimation algorithms for altimeter waveform parameter estimation. The authors derive a simple expression for the bin-to-bin and pulse-to-pulse correlation of altimeter waveforms. This expression is a triple convolution of the specular point probability density function, a product of altimeter point target responses, and a generalized surface impulse response. This result is analogous to the usual expression for the mean altimeter waveform. The authors compare these theoretical predictions against real data, using measurements from the Skylab and Geosat altimeters. Finally, they present a simple application of the results to altimeter system design