【摘要】 采用DEM数据得到每一个像元所处的方位和坡度,结合TM影像成像时的太阳高度角和方位角,得到太阳直射光入射角的余弦值;将其与太阳直射光修正系数相结合,建立起TM影像与DEM的地形光照模型。将DEM数据转换为和TM影像相差系数为fL0的地形光照模型图,通过其选取DEM和TM影像的同名地物点进行几何配准校正。将该方法应用于广州市DEM数据和TM影像的配准工作。经验证,校正后的DEM数据和标准的TM数据之间的误差在1个像元以内。更多还原

【Abstract】 By use of the DEM data to get the azimuth and slope gradient of each pixel,combined with the sun altitude angle and azimuth when TM image was imaged,the cosine of an angle of incidence of direct sunlight is gotten.When it is combined with the optical correction coefficient of direct sunlight,the terrain illumination model of TM image matched with DEM is build.DEM data can be converted into a terrain illumination model image,whose different coefficient with TM image is fL0.By the model to select the same objects on TM image and DEM,geometrical matching rectification will be carried out.The matching of DEM and TM image of Guangzhou is taken as a demonstration.By comparing the result with the TM image,it is found that the error is less than one pixel,that shows the method is advisable.更多还原