高分七号卫星多源遥感数据精度优化与评估

Accuracy optimization and assessment of GF-7 satellite multi-source remote sensing data

高分七号卫星是国内首个亚米级双线阵立体成像卫星,同时配有两套激光测高仪和激光足印相机,可同期获取多源遥感数据。文中采用高分七号卫星获取的多源遥感数据进行平面和高程精度优化,利用激光测高数据对立体影像密集匹配的DSM进行偏度、中值、线性和二阶多项式模型和高程优化评估,利用足印影像对DOM进行一阶仿射变换方法和平面优化评估,并利用外业控制点对无控平面高程、激光高程优化、足印-激光平面高程优化、外业-激光平面高程优化等不同优化模型的结果进行精度评估。实验结果表明,利用激光测高数据可明显优化DSM高程精度,无控DSM高程误差平均值为-4.268 m,中误差为4.518 m,经过中值模型优化后的DSM高程误差平均值提升为-0.272 m,中误差提升为1.508 m,经过线性模型优化后的DSM高程误差平均值提升为-0.320 m,中误差提升为1.351 m;利用足印影像可改善DOM的平面精度,平面误差平均值从13.606 m提升到5.341 m,中误差从13.626 m提升到5.495 m。

The GF-7 satellite is the first sub-meter two-line-array stereo imaging satellite of China. It is equipped with two sets of laser altimeters and laser footprint cameras to capture multi-source remote sensing data simultaneously. In this paper, the multi-source remote sensing data of GF-7 satellite were used to promote the horizontal and vertical accuracy, which used laser altimetry data to optimize the vertical accuracy by skewness,median, linear polynomial and quadratic polynomial model, and the footprint image was used to optimize the horizontal accuracy in the first-order affine transformation method. Moreover, the accuracy of uncontrolled planeelevation, laser elevation optimization, footprint-laser plane-elevation optimization and field-laser plane-elevation optimization were evaluated through the field control points. The experimental results show that the vertical accuracy of DSM can be improved significantly with the support of laser altimetry data. The mean vertical error of the DSM produced without GCPs is-4.268 m and the mean square error is 4.518 m. While the mean vertical error and mean square error of the DSM optimized by the median model are improved to-0.272 m and 1.508 m,and the mean vertical error and mean square error of the DSM optimized by linear model reach-0.320 m and1.351 m. The horizontal accuracy of DOM can be improved by the footprint image. The mean horizontal error is optimized from 13.606 m to 5.341 m, and the mean square error is optimized from 13.626 m to 5.495 m.