Potential Accuracy of Joint Parameter Estimate by Space-Based Radar Altimeter

Abstract

The subject of research is a space-based radar altimeter. Modern satellite altimeters along with the instant distance to an earth surface are to measure the sea wave height and scattering cross section per unit of a probed spot. Ranking of specific measuring algorithms for the quantities mentioned is carried out by comparison of their accuracy indicators with the reference which is minimum theoretical estimate variance established by the Cramer-Rao bound. Calculation of such bounds in case of joint estimate comes down to inversion of the Fisher information matrix. In the paper, this task is solved within the framework of Gaussian approximation of both compressed ranging pulse and antenna pattern. As a result, expressions for noise variances of joint estimates of satellite height, significant wave height and power SNR are obtained. Quantifying the received equations into figures is implemented by numerical integration.

Keywords

• satellite altimeter
• joint estimation
• maximum likelihood estimate
• cramer-rao bound
• fisher matrix