RIGOROUS SENSOR MODELING AND TRIANGULATION FOR ORBVIEW-3

BAE Systems is a leader in geospatial image processing using a wide range of image sources. Photogrammetric processing for end-user products such as orthophotos, digital terrain models, and feature data requires rigorous sensor modeling or highly accurate approximations to the rigorous sensor model in the form of RPC (Rational Polynomial Coefficients) or RSM (Replacement Sensor Model). Both rigorous and approximate sensor models must allow triangulation. In many cases triangulation is necessary to improve accuracy for derived products, but in some instances, the input georeferencing metadata associated with the sensor may meet accuracy requirements. A sensor model, as defined in BAE Systems' software products SOCET SET ® and SOCET GXP ® , consists of three components: support data input/output; ground-to-image function (or, alternatively, image-to-ground function); triangulation. Triangulation with a sensor model requires: identification of the sensor model parameters that are adjustable; determination of default accuracies for each adjustable parameter; error propagation model. This paper outlines the approach for implementing the rigorous OrbView-3 sensor model, including reading support data, implementing the image-to-ground function, and triangulation, illustrated with an OrbView-3 data set. INTRODUCTION: REVIEW OF SENSOR MODELING