基于MISR多角度光学遥感影像的海面风速估算实验

Estimation experiment of sea surface wind speed based on MISR multi-angle optical remote sensingimages

太阳耀光是来自粗糙海面的直接太阳反射光,其强度与海面粗糙度密切相关,而海面粗糙度主要受海面风场影响。因此,包含太阳耀光信息的光学遥感影像在海洋动力过程和海面风速探测中具有积极意义。本文利用2016年2月到2017年3月期间成像的25幅Terra卫星MISR(Multi-angle Imaging Spectro Radiometer)传感器的多角度遥感影像,分别提取了太阳的高度角和方位角、正视和后视影像的卫星观测角、方位角等信息,校正获得正视和后视影像的太阳耀光辐射强度,进一步反演海表面粗糙度信息,进而计算海面风速。最后利用ECMWF(European Centre for Medium-Range Weather Forecasts)的模式风速数据与反演获得的风速结果进行对比验证。结果表明,两者的相关系数较高(R=0.745),均方根误差和平均绝对偏差值分别为1.514m·s^(-1)和1.319m·s^(-1)。初步实验结果表明,利用MISR多角度光学遥感影像估算海表面风速是可行性的。

The sun glitter is caused by the direct reflection of the sun light from the rough sea surface,and its intensity is strongly affected by the sea surface roughness.The sea surface roughness is mainly affected by the sea surface wind field.Therefore,the remote sensing images containing sun glitter information are of great significance in ocean dynamic processes detection and sea surface wind speed estimation.In this study,25 remote sensing images of MISR（Multi-angle Imaging Spectro Radiometer）sensor equipped with Terra Satellite acquired from February 2016 to March 2017 were used.The zenith angle,azimuth angle and sensor angles from the MISR images were obtained,then the normalized radiation intensities of sun glitter were corrected,while the sea surface roughness were further acquired,and the sea surface wind speed was estimated.Finally,the estimation results were compared to the model wind speed data of ECMWF（European Centre for MediumRange Weather Forecasts）.The results show that the correlation coefficients（0.745）are high,and the root mean square error and the mean absolute deviation error are 1.514 m·s^（-1） and 1.319 m·s^（-1）,respectively.The preliminary experimental results show that it is feasible to extract the sea surface wind speed by using MISR multi-angle optical remote sensing images.