基于ICESat-2数据的高程控制点提取和精度验证  

Elevation Control Points Extraction and Accuracy Validation based on ICESat-2 Data

作　　者：郑迎辉 张艳[1] 王涛[1] 赵祥 张昆 王龙辉 ZHENG Yinghui;ZHANG Yan;WANG Tao;ZHAO Xiang;ZHANG Kun;WANG Longhui(Information Engineering University,Geospatial Information Institute,Zhengzhou 450001 China)

机构地区：[1]信息工程大学地理空间信息学院,郑州450001

出　　处：《地球信息科学学报》2022年第7期1234-1244,共11页Journal of Geo-information Science

基　　金：装备技术基础科研项目(192WJ22007)。

摘　　要：ICESat-2(Ice, Cloud and land Elevation Satellite-2)数据的平面定位精度达到米级,高程定位精度达到亚米级,但受各种外界因素的影响,部分激光足印点的高程精度较差,不能用作高程控制点。针对上述问题,本文提出一种适用于ICESat-2数据的多参数联合的高程控制点提取方法。该方法首先利用内置参数辅助检查激光足印点数据质量,滤除异常激光足印点,然后参考内置DEM(Digital Elevation Model)数据进行高程粗差剔除,最后结合云量标记、坡度参数以及时间标记属性参数设置阈值精细筛选,保留满足质量检查、坡度小、云量少的激光足印点作为最终高程控制点,并利用高精度参考高程数据进行精度验证。为验证本文方法的有效性,选取郑州西部、北科达他州西南部、印第安纳州北部地区的ICESat-2激光数据(高程平均绝对误差分别为3.711、0.582、0.333 m)进行高程控制点提取实验,实验结果表明,筛选后的激光足印点平均绝对误差分别达到0.827、0.393、0.131 m,该提取方法在多种地形场景下均能够提取出一定数量且精度较高的高程控制点,不仅能为1:50 000以及1:10 000立体测图提供数据支撑,还能为全国甚至是全球高程控制点提取和高程控制点库建设提供参考。The horizontal positioning accuracy of ICESat-2(Ice, Cloud, and land Elevation Satellite-2) data reaches the meter level, and the plane positioning accuracy reaches the sub-meter level. Nevertheless, it is inevitable that poorly accurate laser footprint cannot be used as elevation control point due to various external factors. Therefore, this paper proposes a technique that employs multiple parameters to extract high-precision elevation control points from ICESat-2 data. At first, this method utilizes the built-in parameters to check the quality of the laser footprint point data, eliminating abnormal laser footprint points. The second step is to remove the elevation error in reference to the built-in Digital Elevation Model(DEM) data. The final step aims to set thresholds for fine screening to reserve the elevation points that meet the criteria of quality inspection, small slope, and low cloud cover based on attributes parameters such as cloud cover marker, slope parameter, and a time marker. Moreover, high-precision reference elevation data are also used to verify the selected elevation control points. To verify the effectiveness of the proposed technique, we employed the ICESat-2 laser data from western Zhengzhou, southwestern part of North Kodata, and northern Indiana(mean absolute height elevation is3.711 m, 0.582 m, and 0.333 m, respectively) to extract elevation control points. Experimental results show that the mean absolute errors of laser footprints were 0.827 m, 0.393 m, and 0.131 m after screening, respectively.The extraction method can extract a certain number of high-precision elevation control points in multiple terrain scenarios. It also provides data support for 1:50 000 and 1:10 000 stereo mapping and offers references to the elevation control points extraction and elevation control point database construction throughout China or around the globe.

关 键 词：ICESat-2 ATLAS ATL08 激光测高 激光足印点 高程控制点 提取 精度验证 

分 类 号：P208[天文地球—地图制图学与地理信息工程]