中文摘要：

将ICESAT测高数据与动态GPS数据进行了比较,对于沿卫星地面轨迹上的点,采用直线内插求定GPS点的高程,与GPS大地高的最小差异为0.76 m;对于偏离卫星地面轨迹的点,分别按与GPS点经、纬度差异小于5″、10″、20″的原则选取卫星地面轨迹上的点,比较了算术平均等3种方法内插GPS高程的效果,与大地高之差在2 m以内。选取ICESAT卫星激光测高地面轨迹与GPS动态轨迹交叉位置附近的点,分别用ICESAT测高数据与GPS数据进行内插,GPS点与ICESAT地面轨迹上的内插点的经度之差最小为0.000 03°,高程之差最小为0.381 m。在卫星地面轨迹附近选取点位进行静态GPS测量,比较了ICESAT与GPS观测结果之间的差异,分析了不同内插方法对结果的影响,在高山地区,最小高程差为0.103 m,最大差为27.475 m。

英文摘要：

The elevations from ICESAT were compared with that from GPS RTK and static GPS measurements.For points along the satellite ground tracks,linear interpolation was used to get the heights of GPS points and compared to the geodetic heights,a minimum of 0.76 m is found for the GPS RTK points.For GPS points near the satellite ground tracks,the points along the ground track are selected by the longitude and latitude differences,5″,10″ and 20″ are used respectively.The heights of the GPS points were interpolated using different interpolation methods,such as arithmetic average,spline,etc..At the point where path of GPS RTK intersects with the ICESAT ground track,a minimum height difference of 0.381 m was found.Static GPS measurement about 45 minutes were carried out near the ICESAT ground tracks.And the coordinates were solved using the continuous operating reference stations with an accuracy better than 0.08 m.A minimum height difference of 0.103 m was found between GPS and ICESAT.