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TitlePrecise Geometric Processing of Stereo MEIS Imagery
AuthorGibson, J R; Buchheit, M
SourceISPRS, Symposium, Proceedings, Commission 7, Victoria, Canada, September 17-21; 1990 p. 791-798
Alt SeriesEarth Sciences Sector, Contribution Series 20040970
Alt SeriesRESORS 1084757
AbstractThis paper discusses the considerations involved in preparing and processing electro-optical stereo imagery from an airborne Multi-detector Electro-optical Imaging Scanner known as MEIS for input into Geographic Information Systems for Remote Sensing analysis or other interpretative applications. MEIS was built by Macdonald, Dettwiler and Associates for the Canada Centre for Remote Sensing (CCRS) and has been evaluated extensively over the past several years. The MEIS was subsequently modified by CCRS to have a stereo imagery acquisition mode by adding external mirrors to create both a forward-looking and an aft-looking channel. These two channels operate simultaneously to provide single-pass stereo coverage. Due to the limited swath width of the present MEIS instrument, it is frequently necessary to fly several parallel flight lines in order to obtain coverage of a desired test area. This paper outlines the procedures that are followed in building up a composite imagery mosaic of the coverage area based on several individual flight lines. The adjustment of the imagery to ground control points is based on rigorous photogrammetric techniques involving the Collinearity and Coplanarity Conditions for the MEIS imager and implicit use of data from the associated inertial navigation system. The adjustment allows for the simultaneous solution of multiple input flight lines and is able to accommodate both fore/aft and side to side stereo imagery. The system computes a low order polynomial estimator to model the errors of the inertial navigation system data and then adjusts the position and attitude data after the best fit to the control points has been achieved. The corrected position data may then be used in the subsequent geometric processing of the imagery. Some of these processing stages include: The removal of terrain height distortions necessary for the generation of ortho-imagery; a simple radiometric balancing necessary before an imagery mosaic may be made and in the future; generation of terrain height data from the forward and aft looking channels. The paper summarizes the results of several accuracy evaluations of the fit of imagery to ground control points. There is also a sample of an ortho-imagery mosaic to illustrate the effects of the correction processing.

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