Photogrammetric Analysis of Horizon Panoramas: The Pathfinder Landing Site in Viking Orbiter Images

Abstract

Tiepoint measurements, block adjustment techniques, and sunrise/sunset picture were used to obtain precise pointing data with respect to north for a set of 33 IMP horizon images. Azimuth angles for five prominent topographic features seen at the horizon were measured and correlated eith locations of these features in Viking Orbiter images. Based on this analysis, the Pathfinder line/sample coordinates in two raw Viking images were determined with approximate errors of 1 pixel, or 40 m. Identification of the Pathfinder location in orbit imagery yields geological context for surface studies of the landing site. Furthermore, the precise determination of coordinates in images together with the known planet-fixed coordinates of the lander make the Pathfinder landing site the most important achor point in current control point networks of Mars.