SZ-4雷达高度计搭乘神舟4号飞船（SZ-4）于2002年12月30日发射入轨,按预定模式工作,获得了大量有效的观测数据。SZ-4雷达高度计是中国第一个上星工作的实验性海洋雷达高度计,为中国海洋动力环境卫星的发展奠定了基础。本文系统地论述了SZ-4雷达高度计系统方案、系统实现和在轨测量结果。

SZ-4 radar altmi eter, the firstChina’s spaceborne expermi ental radar altmi eter launched onDec. 30th2002, had obtained plenty ofscientific data according to the pre-designed operationalmodes. In thispaper, the system scheme, the system realization, and themeasurementresults ofSZ-4 radaraltmi eterare introduced. As the key technologies, the sea echomodelwhich describes the scattering course ofaltmi eter, the fullde-ramp processwhich realizes the pulse compress for the high resolution, and themaxmi um likelihood estmi ationwhich performs the tracking algorithm on board are discussed in detai.l The characteristics forSZ-4 altmi eterhardware system are outlined, and theRF unit and the digital processing unitof this altmi eter are also introduced. This paper discusses the operation modes on orbit for SZ-4 altmi eter, which are bias/noise measurement, inner calibration, acquisition, tracking, communication with satellite host, data transfers, and instrument status detection. Because the altmi eterand the scatterometer installed on SZ-4worked by turn due to the power lmi it, the obtained data ofaltmi eterwere notconsecutive. Thisnon-consecutive observation restricts the application of the altmi eter. The significantwave heights are obtained from the data on Feb. 8th2003, and the resultswere smi ilar to thatof theERS-2. From these results, we can conclude that this expermi enton orbithad validated the function of the SZ-4 altmi eter, and itwould be a great contribution to the China’s future Seasat.