Research Of Attitude Variation Effects On Three-line-array Cameras In Remote Sensing Push-broom Stereo Photogrammetry

Three-line-array (TLA) push-broom cameras have been widely used in remotesensing stereo photogrammetry, eithor sapceborne or airborne. Due to the specialimaging mechanism, the influence that brought by many factors such as attitudevariation, topographic relief, vibration, rotation of earth, is more complicated thanother cameras. Key thoeries and technologies of attitude variation effects on TLApush-broom cameras in imaging and stereophotogrammetry are studied in this paper.The main research contents are as follows:1. The development of push-broom linear array CCD cameras has been reviewed,and many typical cameras of single linear array CCD, dual linear array CCD and threelinear arrays CCD are introduced in detail. Both imaging parameters andstereophotogrammetry parameters of these linear array CCD camers are listed.Stereoimaging principle and features of images of TLA push-broom cameras arestudied. The common coordinate systems of image space and their transformationrelation are intoduced. The common used mathematical models for TLA push-broomcameras and their application scope and positioning precision are also reviewed.2. The image motion model for TLA push-broom cameras is presented in this paper.Both aircraft velocity and attitude instability are taken into account in modeling imagemotion. Effects of aircraft pitch, roll, and yaw on image motion are analyzed based ongeometric relations in designated coordinate systems. Quantitative analysis to imagemotion is then conducted in simulation experiments. The results have shown thatimage motion caused by aircraft velocity is space invariant whilst image motioncaused by aircraft attitude instability is more complicated. Pitch, roll, and yaw allcontribute to image motion to different extents. Pitch dominates the along-track imagemotion and both roll and yaw greatly contribute to the cross-track image motion.These results provide a valuable base for image motion compensation to ensure highaccurate imagery in aerial photogrammetry.3. The positioning error model for stereophotogrammetry using TLA push-broomcameras is established base on space intersection principle. Experiments are carriedout based on Chang’E-1TLA push-broom camera parameters of imaging and orbitand attitude control. Effects of three attitudes (pitch, roll and yaw), baseline, stereoimage pair coordinates and focal length are analyzed. 4. An approach of semi-physical simulation for attitude instability using remotesensing TLA push-broom cameras is presented. The design scheme for three-axisattitude control module is described, and two physical models of high precision aremade using real lunar terrain elevation data downloaded from NASA. An effectiveapproach for selection of appropriate terrain modeling methods in forming a digitalelevation model (DEM) is proposed. This approach achieves a balance betweenmodeling accuracy and modeling speed. A support vector machine classifies terrainsurfaces into either complex or moderate based on a terrain complexity indexassociated with the terrain elevation range. The attitude variation is conducted insemi-physical simulation experiments, the original videos are captured, and imagestrips of TLA camera are extracted from these videos. Elevation errors of the fivemark points, located on the physical terrain models, which are produced by attitudesvariation, are calculated and analyzed, based on these image strips, and the effectrules on the elevation positioning accuracy caused by attitudes are proved. The imagemotion caused by rolling is compensated based on the mathematical models that areproposed in this paper, and the compensation result proves this model is correct.