大面积平坦区高分七号卫星影像无控成图研究

Research on Uncontrolled Mapping of GF-7 Satellite Image in Large Flat Area

针对大面积平坦区域卫星影像无控成图精度低的问题,利用已有数字正射影像图和数字高程模型作为纠正底图控制数据,对高分七号卫星在轨测试数据开展了无控高精度成图研究。实现了高分七号卫星影像基于有理函数模型的快速数字微分纠正、配准融合、色彩校正,并统计分析了利用前、后视全色立体影像生成数字表面模型方式纠正和仅利用后视全色影像、已有数字高程模型单独纠正的精度,验证了在大面积平坦区域,无地面控制点的情况下,快速纠正高分七号卫星影像,生成平面位置精度满足1∶10 000成图要求的数字正射影像,高程精度满足1∶25 000的数字高程模型制作要求的可行性。试验生成的数字正射影像色调自然、纹理清晰、分辨率高达0.6 m,既满足1∶10 000数字正射影像成图要求,又节约人工成本。

In order to solve the problem of low accuracy of satellite image mapping without control in large flat area,the existing DOM and DEM are used as the as the rectification base map control data,and the high precision mapping research is carried out on the on-orbit test data of GF-7 satellite.The rapid digital ortho rectification,image fusion and color rectification of GF-7 image based on RFM are realized.The accuracy of DSM rectification by using front and rear view panchromatic stereo images and the existing DEM rectification by using only rear view panchromatic images is statistically analyzed.It is verified that in the case of large flat area and no ground control points,the feasibility of fast rectifying GF-7 image and generating digital orthophoto with plane position accuracy of 1∶10 000 DOM requirements and elevation accuracy of 1∶25 000 DEM,the DOM generated by the test has natural hue,clear texture,resolution up to 0.6 m,satisfying the requirements of 1∶10 000 DOM,also saving the labor cost.