Radar Backscatter Measurement Accuracies Using Digital Doppler Processors in Spaceborne Scatterometers

The normalized standard deviation, Kp, of radar backscatter measurements using digital Doppler processors in spaceborne scatterometers is derived. The Kp expression for analog Doppler filter processors, such as that used in the Seasat scatterometer [7] is shown to be a special case of the derived Kp expression. A connection to Welch´s power spectrum estimation results [6] is also made. Tradeoff studies in digital filter design such as hardware complexity, computational speed, and system performance can be performed based on this Kp expression. We briefly discuss a current application in the design of the NASA scatterometer (NSCAT) to be flown in 1990. This derivation should be useful for system design and analysis of other radar remotesensing instruments.