Approximate Epipolar Resampling of Mars Express HRSC LinearPushbroom Imagery Based on Projection Trajectory Method

The High Resolution Stereo Camera(HRSC) on the European spacecraft Mars Express has high spatial resolution and global coverage. Thus，global high resolution topographic data from the Martian surface can be derived through photogrammetric processing of HRSC data.，butthe accuracy and efficiency of image matching can be improved with geometric constraints of the epipolar line. A approximate epipolar resampling method which is fit for HRSC linear pushbroom imagery is proposed. Firstly，the epipolar geometry of HRSC image is analyzed using a projection trajectory method.Then，the original HRSC images were differentially rectified into a normalized image. Next，the epipolar geometry in the normalized image is analyzed and the approximate epipolar line direction determined. Lastly，the epipolar image is generated through epipolar resampling in normalized image. Experimental results demonstrate the feasibility of the proposed methodThe parallax in the y direction is less than one pixel in the epipolar resampled image.Moreover，the geometric distortion is decreased when image matching is performed on normalized images.