The Research Of Geometrical Rectification And Adjustment Of Airborne Three Linear Array Image-ADS40

Airborne digital sensors-ADS40is a three-line pushbroom scanner sensor, adopts linear central projection, which can get digital image with radiometric resolution and high spatial, and improve the efficiency of managing the photogrammetry image. But during CCD detector sampling, GPS/IMU(POS) is affected by the flight platform, the position and attitude angles are changed. So there will be some distortion. It not only influences visual effect, but also influences image matching and stereoscopic observation. Meanwhile, although the ADS40can get high data accuracy to meet the needs of small-scale mapping, but can not meet the needs of large-scale mapping, especially in urban mapping, such as1:1000,1:500etc. Therefore, adjustment for POS data is a necessary step. Therefore, it is very important to rectify and adjust the distorted image.This paper introduces the ADS40airborne digital sensor model formation, the system parameter, operating principle, and then finish the following specific work:1、Aim at the rectification problem, this paper mainly research on rectification method of geometrical distortion of ADS40airborne linear array image, establishes Mathematical models and realizes ADS40coordinate transformation through corresponding mapping relation on this basis. It is the basic and linchpin of geometric rectification. Thus, this paper expatiates the principle of digital rectification, and according to ADS40airborne digital image, discusses direct rectification method and indirect rectification method.2、In the process of indirect method, the back project need to calculate the best scan line. This paper states the binary-search method and the sequence search method, and on this basis, this paper has improved the algorithm to improve the search efficiency. Besides, this paper uses the partition rectification method for ADS40image to improve the speed of image reading and processing.3、Aim at the problem of adjustment, this paper focuses on the adjustment model which is applicable to ADS40, mainly on the three mathematical models:the low-order polynomial model, the piecewise polynomial model and the orientation image model.Based on the above principles and methods, we use the C++programming language to implement the proposed geometric correction and adjustment. For geometric correction using two kinds of direct and indirect methods, then draw the appropriate conclusions; for adjustment problems, we use the low-order polynomial model experiments, and with the results of comparing the original data, then draw the appropriate conclusions.37figures,3tables and56references.