Radar altimeter phase A study

A 13.4 to 14 GHz altimeter, for determining average ocean profile, significant wave height, and wind speed, is described. A full deramp concept was chosen. The echo RF signal is mixed with a replica of the transmitted signal, suitably time delayed, in order to align it with the chirped echo from the mean ocean level. The IF bandwidth is dimensioned according to the maximum expected wave height. The signal processing unit (digital) consists of a multiplier-accumulator and a microprocessor which performs quasi-real time and differed time operations. A digital precision delay generator manages the unit. The IF signal is converted into a video signal. Video signals are converted into 5 bit digital words. System reliability is assured by full redundancy.