%0 Journal Article
%T SZ-4 Radar Altimeter and Its Measurement Results on Orbit<br>SZ-4雷达高度计及其在轨测量结果
%A XU Ke
%A LIU He-guang
%A <br>许可
%A 刘和光
%J 遥感学报
%D 2007
%I 
%X SZ-4 radar altimeter,the first China's spaceborne experimental radar altimeter launched on Dec.30th 2002,had obtained plenty of scientific data according to the pre-designed operational modes.In this paper,the system scheme,the system realization,and the measurement results of SZ-4 radar altimeter are introduced.As the key technologies,the sea echo model which describes the scattering course of altimeter,the full de-ramp process which realizes the pulse compress for the high resolution,and the maximum likelihood estimation which performs the tracking algorithm on board are discussed in detail.The characteristics for SZ-4 altimeter hardware system are outlined,and the RF unit and the digital processing unit of this altimeter are also introduced.This paper discusses the operation modes on orbit for SZ-4 altimeter,which are bias/noise measurement,inner calibration,acquisition,tracking,communication with satellite host,data transfers,and instrument status detection.Because the altimeter and the scatterometer installed on SZ-4 worked by turn due to the power limit,the obtained data of altimeter were not consecutive.This non-consecutive observation restricts the application of the altimeter.The significant wave heights are obtained from the data on Feb.8th 2003,and the results were similar to that of the ERS-2.From these results,we can conclude that this experiment on orbit had validated the function of the SZ-4 altimeter,and it would be a great contribution to the China's future Seasat.
%K SZ-4<br>雷达高度计
%K 在轨工作
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=A41A70F4AB56AB1B&jid=F926358B31AC94511E4382C083F7683C&aid=62037D0972AAB29D&yid=A732AF04DDA03BB3&vid=708DD6B15D2464E8&iid=E158A972A605785F&sid=AC2617B68B137D9D&eid=A48DE16C07AAAB06&journal_id=1007-4619&journal_name=遥感学报&referenced_num=0&reference_num=9