基于GLAS激光测高数据的ZY-3全球DEM精度评估方法

ZY-3 Global DEM Accuracy Evaluation Method Based on GLAS Laser Altimetry Data

我国全球DEM数据产品的精度验证主要采用基于地面控制点和基于第三方数据评估的方法,考虑数据的可得性、效率及可靠性,提出使用GLAS激光测高数据来评估全球DEM精度的方法。基于GLAS数据特性,首先通过光斑范围内的卷积使DEM高程值滑动平均;其次通过顾及距离、方向和高程变化趋势的GLAS条带遍历以构建最小二乘搜索,从而纠正GLAS数据的偏移量,对DEM进行可靠的精度评定。对3个不同类型地区的试验证明,所使用的方法较传统全球DEM精度评估方法具有更强的通用性,更好的适宜性,更高的效率。

The accuracy verification of global DEM data products in China is based on ground control points and third-party data evaluation methods.Considering the availability,efficiency and reliability of data,this paper proposes the method of evaluating the GLAS laser elevation data.Based on the characteristics of GLAS data,the DEM elevation value is slid average by convolution in the spot range.Secondly,the least square search is constructed by GLAS strip traversing considering the changing trend of distance,direction and elevation,so as to correct the offset of GLAS data and evaluate the accuracy of DEM reliably.Compared with the existing DEM accuracy evaluation methods,the methods used in this paper are more versatile,more suitable and more efficient.Through the experiments in three regions,the DEM accuracy used in this paper is better and more efficient.