Abstract: Of the active microwave remote sensors for ocean observa-tion,the Fine Radar Altimeter is a satellite payload of high benefitand vast use,which has been confirmed on a global scale.Seasat RadarAltimeter is a critical tool for all-weather observation.While the geoidis finely determined,the results are very useful for the research anddevelopment of oceanography,geodetic topograph,ocean deep survey,morning and evening tides,ice,wind,wave etc.In this paper,theresearch is only on that for the frequence flow and the specificationsanalysis of main parts and subsystems of Seasat Radar Altimeter system.