POSEIDON solid state altimeter

A Semianalytical Model of the Synthetic Aperture, Interferometric Radar Altimeter Mean Echo, and Echo Cross-Product and Its Statistical Fluctuations

“…In the pulse-limited case, the functions F in (16) can be given analytical form by expanding the impulse response of [19] [see also (36)] and allowing for earth sphericity and the ellipticity of the antenna gain as has been done by Wingham and Wallis [32]. In this paper, we have not made use of these expressions because having necessarily to compute (16) numerically in the SAR case; it is then simple (and introduces least possibility of error) to set D 0 = d ≡ 1 and ξ k = 0 and recompute the result.…”

“…Successive satellites, from Seasat (1978) onward, have had radar altimeters among their payload, and the use of radar altimeter observations in operational forecasting of ocean dynamics, waves, and winds is now familiar and well established [9]- [11]. While the intervening period has seen a continued improvement in the accuracy and precision of satellite altimeter measurements, arising variously from the improvement in gravity modeling and microwave tracking systems (see [12], [13]), increases in the pulserepetition frequency (PRF) [14], and the introduction of dual frequency measurements (see [14], [15]) and of solid-state power amplification [16], the design of radar altimeters has not altered greatly from that of Seasat [17], [18]: a normal incidence, full-deramp, linear frequency-modulated radar with a circular antenna of around 1-m diameter operating at a central frequency of 13.6 GHz with 320-MHz bandwidth. Similarly, the ocean-surface parameters derived from these measurements use, essentially, the model of the normal incidence scattering of the sea surface developed at the time and expressed in a closed form in [19].…”