利用GLAS激光测高数据评估DSM产品质量及精度优化

提出了一种利用卫星激光测高数据直接优化提升数字表面模型（DSM）产品精度的方法。选取境外中亚地区的资源三号DSM开展试验，通过采用多准则约束方法提取激光高程控制点，分别利用偏度、中值、线性、二次多项式等进行DSM误差修正，发现4种模型均能有效消除DSM系统误差，其中基于二次多项式的方法更适用于平地和丘陵地貌，线性模型更适用于高山地貌。试验验证了采用卫星激光测高数据优化境外DSM技术流程的可行性，最终可提高DSM的绝对高程精度。

Quality assessment and accuracy optimization of DSM using GLAS laser altimetry data

In this paper, a new method using satellite laser altimetry data directly is proposed to optimize and improve digital surface model (DSM) product accuracy. The experiment is implemented in central Asia, and DSM is produced by ZY-3 satellite. The elevation control points are selected from laser altimetry data based on multi-criteria constraint. Then DSM is corrected by the elevation control points using skewness, median, linear polynomial, quadratic polynomial model. The four models can effectively eliminate DSM systematic errors. In addition, the quadratic polynomial model is more applicable to flat and hilly land, and the linear polynomial is more applicable to alpine region. Preliminary test results show that the technical process of DSM accuracy optimization based on satellite laser altimetry data is feasible and the elevation accuracy of DSM is favorable after correction by the four models.