The Ice,Cloud and Land Elevation Satellite-2(ICESat-2),a new spaceborne light detection and ranging(LiDAR)system,was successfully launched on September 15,2018.The ICESat-2 data increase the types of spaceborne LiDAR ...The Ice,Cloud and Land Elevation Satellite-2(ICESat-2),a new spaceborne light detection and ranging(LiDAR)system,was successfully launched on September 15,2018.The ICESat-2 data increase the types of spaceborne LiDAR data archive and provide new control point data for large-scale topographic mapping and geodetic surveying.However,the accuracy of the ATL 08 terrain estimates has not been fully evaluated on a large scale and in complex terrain conditions.This article aims to quantitatively assess the accuracy of ICESat-2 ATL 08 terrain estimates.Firstly,the ICESat-2 ATL 08 terrain estimates were compared with the high-precision airborne LiDAR digital terrain model(DTM),and impacts of acquisition time,vegetation cover type,terrain slope,and season change on the terrain estimation accuracy were analyzed.We get the following conclusions from the analysis:1)the mean and RMSE of the terrain estimates of day acquisitions are 0.22 m and 0.59 m higher than that of night acquisitions;2)the accuracy of the ATL 08 terrain estimates acquired in vegetated areas is lower than those in non-vegetated areas;3)the accuracy of the ATL 08 terrain estimates is inversely proportional to the slope,and the elevation error increases significantly when the terrain slope is larger than 30°;4)in the non-vegetation covered area,the accuracy of the ATL 08 terrain estimates of summer and winter acquisitions has no obvious discrepancy,but in vegetated area,the accuracy of winter acquisitions is significantly better than that of summer acquisitions.This research provides references for the selection and application of ICESat-2 data.展开更多
基于高分辨率快速更新无缝隙融合集成预报RISE系统(Rapid-refresh Integrated Seamless Ensemble system),采用华北3 km分辨率快速循环更新的中尺度数值模式CMA-BJ、欧洲中心0.125°分辨率全球数值模式ECMWF、常规自动站和冬奥赛道...基于高分辨率快速更新无缝隙融合集成预报RISE系统(Rapid-refresh Integrated Seamless Ensemble system),采用华北3 km分辨率快速循环更新的中尺度数值模式CMA-BJ、欧洲中心0.125°分辨率全球数值模式ECMWF、常规自动站和冬奥赛道加密自动站逐时观测资料,以北京冬奥会复杂山地为研究区域,对比分析了不同模式背景场对100 m网格分辨率的地面2 m温度和10 m风场融合分析场和1~24 h逐小时间隔预报准确性的影响。对比试验结果表明:(1)采用区域模式和全球模式的预报数据作为RISE系统背景场,均可有效形成复杂山地百米级精细化融合产品,但不同模式背景场对不同气象要素分析和预报性能的影响存在明显差异;(2)对于温度分析场,以CAM-BJ和ECMWF模式的预报数据为背景场的RISE温度分析场空间分布基本一致,分析平均绝对误差(MAE)均小于0.2℃;(3)对于风场分析场,采用高分辨率区域模式比粗分辨率全球模式更能提升RISE高精度风场融合产品精细化水平;(4)对于温度预报,以ECMWF模式的预报数据为背景场的RISE格点融合预报性能显著优于CMA-BJ模式的预报数据为背景场,冬奥高山站和所有站平均预报MAE分别减小10.5%和7.0%;(5)对于风场预报,以CAM-BJ和ECMWF模式的预报数据为背景场的RISE冬奥高山站临近1~6 h风速预报MAE分别为1.42 m s^(-1)和1.30 m s^(-1),7~24 h预报MAE则分别为1.52 m s^(-1)和1.54 m s^(-1),而RISE区域内所有站1~24 h平均MAE分别为1.38 m s^(-1)和1.24 m s^(-1)。研究成果有助于深入理解模式背景场在百米级融合预报中的作用,对提升复杂地形下天气预报准确性有重要的科学意义和业务应用价值。展开更多
基金Projects(41820104005,41904004,42030112)supported by the National Natural Science Foundation of China。
文摘The Ice,Cloud and Land Elevation Satellite-2(ICESat-2),a new spaceborne light detection and ranging(LiDAR)system,was successfully launched on September 15,2018.The ICESat-2 data increase the types of spaceborne LiDAR data archive and provide new control point data for large-scale topographic mapping and geodetic surveying.However,the accuracy of the ATL 08 terrain estimates has not been fully evaluated on a large scale and in complex terrain conditions.This article aims to quantitatively assess the accuracy of ICESat-2 ATL 08 terrain estimates.Firstly,the ICESat-2 ATL 08 terrain estimates were compared with the high-precision airborne LiDAR digital terrain model(DTM),and impacts of acquisition time,vegetation cover type,terrain slope,and season change on the terrain estimation accuracy were analyzed.We get the following conclusions from the analysis:1)the mean and RMSE of the terrain estimates of day acquisitions are 0.22 m and 0.59 m higher than that of night acquisitions;2)the accuracy of the ATL 08 terrain estimates acquired in vegetated areas is lower than those in non-vegetated areas;3)the accuracy of the ATL 08 terrain estimates is inversely proportional to the slope,and the elevation error increases significantly when the terrain slope is larger than 30°;4)in the non-vegetation covered area,the accuracy of the ATL 08 terrain estimates of summer and winter acquisitions has no obvious discrepancy,but in vegetated area,the accuracy of winter acquisitions is significantly better than that of summer acquisitions.This research provides references for the selection and application of ICESat-2 data.
文摘基于高分辨率快速更新无缝隙融合集成预报RISE系统(Rapid-refresh Integrated Seamless Ensemble system),采用华北3 km分辨率快速循环更新的中尺度数值模式CMA-BJ、欧洲中心0.125°分辨率全球数值模式ECMWF、常规自动站和冬奥赛道加密自动站逐时观测资料,以北京冬奥会复杂山地为研究区域,对比分析了不同模式背景场对100 m网格分辨率的地面2 m温度和10 m风场融合分析场和1~24 h逐小时间隔预报准确性的影响。对比试验结果表明:(1)采用区域模式和全球模式的预报数据作为RISE系统背景场,均可有效形成复杂山地百米级精细化融合产品,但不同模式背景场对不同气象要素分析和预报性能的影响存在明显差异;(2)对于温度分析场,以CAM-BJ和ECMWF模式的预报数据为背景场的RISE温度分析场空间分布基本一致,分析平均绝对误差(MAE)均小于0.2℃;(3)对于风场分析场,采用高分辨率区域模式比粗分辨率全球模式更能提升RISE高精度风场融合产品精细化水平;(4)对于温度预报,以ECMWF模式的预报数据为背景场的RISE格点融合预报性能显著优于CMA-BJ模式的预报数据为背景场,冬奥高山站和所有站平均预报MAE分别减小10.5%和7.0%;(5)对于风场预报,以CAM-BJ和ECMWF模式的预报数据为背景场的RISE冬奥高山站临近1~6 h风速预报MAE分别为1.42 m s^(-1)和1.30 m s^(-1),7~24 h预报MAE则分别为1.52 m s^(-1)和1.54 m s^(-1),而RISE区域内所有站1~24 h平均MAE分别为1.38 m s^(-1)和1.24 m s^(-1)。研究成果有助于深入理解模式背景场在百米级融合预报中的作用,对提升复杂地形下天气预报准确性有重要的科学意义和业务应用价值。
