摘要
卫星雷达高度计是海洋遥感监测的重要传感器之一,测高系统和定轨系统是高度计重要的组成部分。若两系统使用不同的系统时钟,则获得的轨道高度和卫星测距值之间可能会存在一个时标偏差,该时标偏差会降低卫星雷达高度计的海面高度测量精度。针对HY-2卫星雷达高度计的时标偏差问题,本文分析了时标偏差对测高精度的影响,介绍了一种使用自交叉点数据估算时标偏差值的方法,并基于HY-2卫星雷达高度计第21个周期数据开展了时标偏差修正实验。时标偏差修正后HY-2自交叉点的海面高度差值(也称"不符值")分布收敛程度有了明显的提高,其RMS均方根值从24.7cm减小到了7.0cm,HY-2与Jason-2互交叉点的不符值的RMS也从16.6cm减小到了7.3cm。这表明本文介绍的时标偏差修正方法可有效地提高HY-2卫星雷达高度计的测高精度。
A satellite radar altimeter is one of the important sensors for an ocean remote sensing.An altimetry system and an orbit determination system are the most important components of the altimeter.If these two systems use different system clocks,there will be a time tag between the satellite altitude and the range which is the distance between the satellite and the sea surface in the nadir-looking direction of an antenna.The time tag can reduce the sea surface height measurement accuracy of the satellite radar altimeter.In this study,for the time tag bias problem of HY-2 satellite radar altimeter,the contribution of the time tag bias is analyzed to the sea surface height measurement accuracy,and a method is introduced to estimate the time tag bias value using self-crossover data.Based on the 21st cycle IGDR（Interim Geophysical Data Record）data of HY-2 satellite radar altimeter,experiments are carried out to correct the time tag bias.After correcting the time tag bias,the degree of convergence for the difference distribution of HY-2 self-crossover sea surface height is improved obviously,and the RMS of the HY-2 self-crossover sea surface height differences is reduced from 24.7to 7.0cm,and the RMS of the co-crossover sea surface height differences between HY-2 and Jason-2 is reduced from 16.6to 7.3cm.This suggests that the method for correcting the time tag bias can improve the sea surface height measurement accuracy of HY-2 satellite radar altimeter effectively.
出处
《海洋学报》
CAS
CSCD
北大核心
2013年第5期87-94,共8页
基金
国家海洋公益性行业科研专项经费项目(201105032-1)
国家高技术研究发展计划(863计划)项目(2013AA09A505)
