垂直与倾斜相机观测对遥感物候参数验证影响的对比研究  

Comparison of vertical and inclined camera observations on the validation results of remote sensing phenological parameters

作　　者：许丽娜 屈永华[1,2] 孙晨曦 万华伟 阿斯娅·曼力克[4] 刘绍民 XU Lina;QU Yonghua;SUN Chenxi;WAN Huawei;ASIYA Manlike;LIU Shaomin(State Key Laboratory of Remote Sensing Science,Beijing 10087,China;Beijing Engineering Research Center for Global Land Remote Sensing Products,Institute of Remote Sensing Science and Engineering,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China;Ministry of Ecology and Environment Center for Satellite Application on Ecology and Environment,Beijing 1000942,China;Grassland Research Institute,Xinjiang Academy of Animal Husbandry Sciences Tianshan North Slope Grassland Ecological Environment Field Positioning Observation and Research Station,Wulumuqi 830057,China;State Key Laboratory of Earth Surface Process and Resource Ecology,Beijing Normal University,Beijing 100875,China)

机构地区：[1]北京师范大学遥感科学国家重点实验室,北京100875 [2]北京师范大学北京市陆表遥感数据产品工程技术研究中心地理科学学部遥感科学与工程研究院,北京100875 [3]生态环境部卫星环境应用中心,北京100094 [4]新疆畜牧科学院草业研究所新疆畜牧科学院天山北坡草地生态环境野外定位观测研究站,乌鲁木齐830057 [5]北京师范大学地理科学学部地表过程与资源生态国家重点实验室,北京100875

出　　处：《遥感学报》2024年第10期2565-2581,共17页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家自然科学基金(编号:42192580,42192581)。

摘　　要：基于卫星遥感的大尺度植被物候监测对于农业生产管理、气候变化响应等领域具有重要意义。卫星遥感提取的物候参数真实性检验常以近地面数字相机观测为数据源。以往验证研究大多关注观测尺度的差异造成的影响,忽略了地面相机与卫星观测天顶角的不一致性。本文将获取的垂直(PhotoNet)与倾斜(PhenoCam)物候相机在相近纬度、同种植被类型的观测站点数据,分别与Sentinel-2卫星提取的物候参数进行对比,系统性地评估2种地面相机观测角度对卫星物候期验证结果的影响。结果表明:相机的观测角度是卫星遥感物候验证研究中的不确定性原因之一;在多数情况下,卫星遥感与垂直观测相机提取的物候期表现出更好一致性,平均相差9 d,而与倾斜观测相机平均相差可达19 d,偏差天数受植被类型和生长阶段的影响;在玉米凋落期至休眠期,垂直观测偏差反而高于倾斜观测;植被冠层方向反射特性和相机视场范围内目标组分差异是引起这种现象的主要原因。本研究证实了地面相机观测角度是卫星物候真实性检验中不可忽视的影响因素,相机野外布设时应充分考虑角度效应带来的验证误差,从而为卫星遥感物候监测提供更可靠的验证数据。In the fields of agricultural production management and climate change research,monitoring large-scale plant phenology with satellite-based remote sensing is crucial to reveal the interaction of biology and nature environment.During validation on remotely sensed phenology information,near-surface digital cameras are often employed as main data sources.However,more efforts were focused on the scale difference between ground and remotely sensed data and rarely on the difference of sensors viewing zenith,i.e.,the satellites mainly adopted the near-nadir observation while cameras were mostly inclined in arrangement.Vertical(PhotoNet)and inclined(PhenoCam)camera observations were acquired at the similar latitude for the same vegetation type,and then these observations were compared with phenological parameters extracted from Sentinel-2 data to assess systematically the effects of camera observation angles on the results of satellite phenological verification.For 16 locations,we compared a Greenness Chromatic Coordinate(GCC)series derived from digital cameras and Sentinel-2.A double hyperbolic tangent model was fitted for each series.The threshold method was applied to the annual complete modeled data,and the curvature extremum method was used for incomplete data to estimate the onset of greenup,the maturity of the green canopy,the peak of season,the end of greenness,and the dormancy of the green vegetation(OG/MG/PS90/EG/DG).Results showed that the viewing zenith of cameras is one of the uncertain sources to validate phenology information from satellite imagery.In most cases,the vertically observed camera showed improved agreement with the phenological parameters extracted by the satellite-based method,with an average bias of 9 days,while a larger bias of 19 days was observed for inclined camera observation.Therefore,the two camera observation methods result in the verification deviations of up to 10 days on average.However,the deviations might be vegetation type and growth stage dependently.The bias of vertical observ

关 键 词：遥感 数字相机 观测角度 卫星物候 近地物候 植被绿度 

分 类 号：X87[环境科学与工程—环境工程] P2[天文地球—测绘科学与技术]