By determination of aerial image orientation and DTM, we can update the existing orthoimage.And the accuracy of experience result is equal to the accuracy of digital photogrammetry.

• 藉由此方式，求定了该航摄影像的外方位最或是值之后，再配合DTM资料，来进行该地区的正射影像更新，并且其结果可达到与一般数值航测作业相同之之精度要求。