机载三维成像仪航带拼接的误差处理研究

Error Processing Technology of Airborne 3D Imager to Mosaic Strips

机载三维成像仪是集成了全球定位系统 (GPS)、姿态测量装置、激光测距仪和光谱成像仪的新一代航空遥感系统 ,它能直接得到地学编码影像和数字地面模型 (DTM) ,而无需地面控制点。利用图像上分布的具有三维坐标的激光点来纠正原始图像 ,并且生成DTM。该文首先分析了机载三维成像仪系统中各种传感器本身的误差和系统之间存在的误差 ,然后介绍了处理系统误差的方法———航带重叠区域灰度平均差值最小算法求解航带间的系统误差 ,同时还设计了一种变权方法来处理随机误差和拼接航带的地学编码图像。通过算例说明了处理算法的正确性。

Airborne 3D imager which integrates global positioning system, attitude measurement unit, scanning laser range finder and spectral imager can produce geo-referenced image and digital terrain models (DTM) without ground control points. The raw image is rectified based on the laser points with known coordinates. Owning to the existence of the error, the geo-referenced images of neighbor strips can not be mosaiced seamlessly. Therefore, it is necessary to eliminate the error. The error source of each component of 3D imager such as GPS error, attitude error and laser range error is analyzed and the system error between the components is also described. Then we focus on the error processing algorithm. The system error is determined and corrected using least mean gray difference in the overlap and the random error is processed by variant weight algorithm in order to mosaic the strips. The test result proves that the error processing methods is feasible.