This application generates a RPC sensor model from a list of Ground Control Points. At least 20 points are required for estimation wihtout elevation support, and 40 points for estimation with elevation support. Elevation support will be automatically deactivated if an insufficient amount of points is provided. The application can optionnaly output a file containing accuracy statistics for each point, and a vector file containing segments represening points residues. The map projection parameter allows to define a map projection in which the accuracy is evaluated. This section describes in details the parameters available for this application. Table  presents a summary of these parameters and the parameters keys to be used in command-line and programming languages. Application key is GenerateRPCSensorModel . Input file containing tie points Input file containing tie points. Points are stored in following format: row col lon lat. Line beginning with # are ignored. Output file containing output precision statistics Output file containing the following info: ref_lon ref_lat elevation predicted_lon predicted_lat x_error_ref(meters) y_error_ref(meters) global_error_ref(meters) x_error(meters) y_error(meters) overall_error(meters). Output Cartographic Map Projection Parameters of the output map projection to be used. Available choices are: Elevation management This group of parameters allows to manage elevation values. Supported formats are SRTM, DTED or any geotiff. DownloadSRTMTiles application could be a useful tool to list/download tiles related to a product. Source.