基于有理函数模型和多项式模型的天绘一号影像几何校正精度评估

Accuracy assessment of TH-1 satellite image geometric correction using rational function model and polynomial model

研究了不同地貌特征的TH-1影像基于多项式模型和有理函数模型的几何校正精度,以及在每种模型下不同控制点个数与几何校正精度的关系.实验结果表明,TH-1影像因光学投影产生的比如扭曲变形等误差较大,有理函数模型中只需较少控制点便可明显提高其几何校正精度;多项式模型中,控制点的数量越多对精度提高越有好处,2阶多项式校正精度最高;在没有参数模型的情况下,高阶有理函数模型是TH-1影像几何校正的最佳选择.

Based on RFM （rational function model） and the polynomial model, the geometric correction precision of TH-1 satellite images was studed on different landforms, and the relationship between the number of GCPs （ground control points） and geometric correction precision was also studied. Experimental results show that TH-1 images have a magnitude distortion caused by optical projection; RFM can obviously improve TH 1 geometric correction precision with only a few GCPs; in the polynomial model, more GCPs can achieve higher correction precision, and 2 order can get the highest correction precision; without a parameter model, high order RFM is the best choice for TH-1 image geometriccorrection.