RFSCAT散射计数据地理定位与误差分析

星载微波散射计是目前唯一能够同时测量海面风速和风向的传感器,在海洋科学研究中发挥着重要作用。散射计获取的地物后向散射只有经过地理定位才能得到包含地物位置信息的有效物理量。因此,散射计地理定位是数据预处理的重要组成部分,与遥感数据的质量密切相关。扇形波束旋转扫描散射计具备扇形固定波束散射计和笔形波束旋转扫描散射计的优势,目前还没有实现在轨运行。基于其工作方式的特殊性,详细分析了该散射计的扫描方式,给出了一种适用于该散射计的地理定位方法,得到了最终的定位结果。然后分析了影响定位结果的误差源,讨论了卫星姿态对于定位结果的影响情况,最终利用HY-2卫星产品评价了该地理定位算法的相对精度指标。

Geolocation and Error Analysis of RFSCAT Microwave Scatterometer Data

Spaceborne microwave scatterometer is the only sensor for directly measuring sea surface wind speed and wind direction at the same time,which plays an important role in marine scientific research.Objects’ backscatter coefficient can become valid physical quantity including position information by geolocation,therefore,geolocation is an important part of scatterometer data preprocessing,and is closely related to the quality of remote sensing data.Rotating range-gated fanbeam Scatterometer is combined with advantages of fixed fanbeam scatterometer and pencil beam rotating scanning scatterometer,which hasn’t been in orbit.Based on the special working type,its scanning type was analyzed in detail,an appropriate geolocation method was proposed,geolocation results were calculated,afterwards error sources were analyzed,the satellite attitude influences on geolocation results were discussed,finally the relative accuracy of geolocation was evaluated using HY-2 satellite data products.