面向水色遥感的无人机高光谱天空散射光影响研究  

Study on the Effect of Sky Scattered Light on the Reflectance of UAV Hyperspectral about Remote Sensing of Water Color

作　　者：钟朴 郭兴健 蒋昕桐 翟颖慧 段洪涛 Pu ZHONG;Xingjian GUO;Xintong JIANG;Yinghui ZHAI;Hongtao DUAN(College of Urban and Environment,Northwest University,Xi’an 710127,China;Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity,Northwest University,Xi’an 710127,China;Key Laboratory of Watershed Geographic Sciences,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]西北大学城市与环境学院,陕西西安710127 [2]西北大学陕西省地表系统与环境承载力重点实验室,陕西西安710127 [3]中国科学院南京地理与湖泊研究所中国科学院流域地理学重点实验室,江苏南京210008

出　　处：《遥感技术与应用》2024年第5期1128-1140,共13页Remote Sensing Technology and Application

基　　金：国家自然科学基金委黄河水科学联合基金(U2243205);陕西省教育厅专项计划项目(22JK0589),陕西省教育厅一般专项基金(21JK0928)资助。

摘　　要：无人机高光谱系统因轻便灵活、成本较低且可获取丰富的光谱信息,近年来广泛应用于环境遥感水质监测相关研究中。但与成熟的卫星监测体系不同,无人机作为位于大气中的遥感平台,天空散射光对准确获取遥感反射率(Rrs)有不可忽略的影响,但目前鲜有研究针对这一问题进行专门的定量化探讨。选择我国第五大淡水湖巢湖及其7条出入湖河流,分别利用无人机高光谱成像仪和地物光谱仪(ASD HandHeld2),对不同观测角度天空光对水体遥感反射率影响开展定量研究。结果显示:天空光对水体遥感反射率的计算具有明显影响,且不同角度天空光存在差异。扣除不同角度天空光反射率与未扣除天空光反射率相比,天顶角45°方向天空光的平均绝对百分比差(MAPD)为11.00%,天顶角0°方向天空光的MAPD为17.21%。依据无人机高光谱成像仪镜头垂直向下的特性,研究确定在水体遥感反射率计算中扣除0°天空光,并进一步应用于悬浮物反演,预测值与实测值均方根误差(RMSE)与平均绝对百分比误差(MAPE)最小,分别为8.89 mg/L和19.60%,证明了其在提高模型反演精度中的贡献。本研究可为无人机高光谱水色遥感研究中遥感反射率的准确获取提供技术参考。UAV(Unmanned Aerial Vehicle)with hyperspectrometer is widely used monitoring water quality in remote sensing of environment due to lightweight,flexible,low-cost,and abundant spectral information.But it is different from the satellite monitoring system,sky scattered light has a non-negligible impact on acquisition of remote sensing reflectance by UAV hyperspectral.Our research will conduct a discussion on this issue.Lake Chaohu and seven rivers around the lake are selected as the study area.The study used hyperspectral image of UAV and ASD HandHeld2 to measure the spectral signal of water,reference panel and sky light to research on the influence of sky scattered light on the remote sensing reflectance of water.Using optimized reflectance calculation method predicting SPM concentration.The result shows that the MAPD is 11.00%at a zenith angle of 45°and 17.21%at a zenith angle of 0°by substracting different sky scattered light.The result of SPM retrieval indicates that the hyperspectral reflectance subtracting 0°sky scattered light has a lower RMSE and MAPE between measured value and predicted value,8.89 mg/L and 19.60%respectively.Obviously,different angles of sky scattered light have effects on the hyperspectral reflectance of UAV.Above result shows that model of hyperspectral reflectance subtracting 0°sky scattered light has a better performance to predicting SPM.We should subtract 0°sky light hyperspectral to calculate reflectance when predicting water quality parameters based on UAV.

关 键 词：无人机 高光谱 天空光 遥感 反射率 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]