An algorithm for geometric correction of full pass TMC imagery of Chandrayaan-1

This paper describes the development of an algorithm for geometric correction of Terrain Mapping Camera (TMC) imagery of Chandrayaan-1 (CH-1). The correction is based on a rigorous sensor model. The algorithm incorporates the camera geometry model, satellite data and lunar control points in a rigorous bundle adjustment updating the satellite model parameters. The model is tested for different strips over the polar and equatorial regions and the results are presented. The planimetric control is identified from the 100 m/pixel USGS Clementine base map mosaic and vertical control is derived from Lunar Orbiter Laser Altimeter (LOLA) data. RMS error of the order 200–300 m in latitude, longitude and height with respect to the references could be achieved using the sensor model with few distributed controls over the strip. The model is used for the orientation of long strips with little or no degradation in orientation quality attainable with a short scene. The results are representative of the stability of the platform and potential of CH-1 for accurate lunar mapping. The algorithm for geometric correction described in this paper is a part of Lunar Mapping System (LMS), which will handle full-pass data for operational generation of Digital Elevation Models (DEM) and Ortho products from TMC images of CH-1.