TM影像几何校正算法的精度比较

Precision comparison of several algorithms for geometric correction of TM image

同大多数的线阵推扫式影像相比,TM影像作为双向扫描型的影像其几何校正方法有其特殊性和复杂性。针对这个问题,本文简要介绍了一般多项式、空间斜墨卡托投影、有理函数模型等几种几何近似校正算法,并利用广州地区的TM影像进行了各种试验分析和精度比较。结果表明:同其他方法相比,空间斜墨卡托投影是一种较好的算法,校正精度最高,能够达到一个像素左右,而且该方法不受地形起伏的影响,无需地面高程信息。

Compared with most linear array push-broom images, the geometric correction methods of TM image, which is doublescanning image is particular and complex. Aimed at the problem as above, in the paper, several methods that are general polynomial, spatial oblique mercator （SOM） projection and rational function model （RFM） are briefly introduced, and by the experiment of TM image in Guangzhou area, the emphasis is put on experimental analysis and precision comparison. It shows that SOM method, whose precision is highest and can reach one-pixel accuracy, is much better and is irrelative to the type of terrains, of course, no needs of elevation.