基于数据矢量特性的MODIS数据几何校正

Geometry correction of MODIS data based on vector feature

MODIS探测器的大扫描角多探元并扫方式是造成扫描图像严重畸变的主要根源。应用基于SWATH的卫星遥感数据处理策略,分析MODIS 1B各分辨率数据空间位置关系及图像数据与经纬度数据的对应情况,结合探测器扫描方式、卫星升降轨和地球曲率等各方面因素按像元地理位置合成图像,抛弃数据光栅特性采取矢量特性实现对像元几何精定位。结果表明:应用该种方法处理的MODIS数据几何校正精度高,方便进行亚像元级精确几何校正,而且可以避免2次或多次像素重定位导致信息丢失,不会出现"BowTie"现象。

The large scanning angle and multiple probe of MODIS detector make the scan image distorted. Based on the SWATH data processing strategy,the relationships of space location of the MODIS 1B data with different resolutions, the corresponding status between image data and longitude and latitude information were analyzed. In order to match the image data, the image was combined by the geographical locations considering the scan method of the MODIS detector, the ascending and descending orbit of the satellite, and the earth curvature and so on. The raster feature of data was replaced by vector feature in this method. The image pixel can be located more exactly through this method. The results indicate that the geometry correction can be done more accurately for MODIS da- ta, so is for that of the sub pixel. This method could avoid information losing when the pixel is relocated, and it never generates BowTie effect.