Triangulation of Spaceborne Three-line Array Imagery with Different Sensor Models

Spaceborne linear array sensors have been introduced into photogrammetry since more than twenty years ago. The traditional solution of frame photograph cannot deal with image data of linear array sensor anymore, because the position and attitude of the spacecraft vary at each scanner line. Thus the number of unknowns would be extremely large and it is impossible to determinate the exterior orientation parameters of each scanner line. A proper approximation has to be applied to model the spacecraft trajectory to reduce the unknowns in triangulation. There are three models feasible to represent the satellite trajectory: Quadratic Polynomial Model (QPM), Systematic Error Compensation Model (SECM), and Orientation Image Model (OIM). Revealing the differences of the three sensor models and relationships between different control strategies and the final accuracy of georeferencing after bundle adjustment is the main purpose of this paper. To fully evaluate the accuracy that spaceborne three-line scanner can achieve, experiments with LMP, SECM and OIM triangulation algorithms are performed with a 500km length data sets under WGS 84 coordinate system.