Prediction of Georeferencing Precision of Pushbroom Scanner Images

Abstract

The precision of georeferencing of pushbroom satellite images without using ground control points is estimated. The study includes what-if scenarios for various precisions of star trackers, GPS receivers, image acquisition timing, interior camera parameters, and digital elevation model (DEM). Moreover, the effects of satellite altitude and sensor positions on the pushbroom array are also taken into account. The probability distribution function of the input parameters is determined by considering the sensor characteristics, environmental effects, and assumptions. The precision of the georeferenced coordinates is estimated by Monte Carlo simulation and differential sensitivity analysis. The analyses provide the most probable georeferenced coordinates and their precision for a certain precision of sensors and imaging geometry. The study is conducted based on the BilSAT orbit and SPOT 5 and Landsat optical system characteristics. An Shuttle Radar Topography Mission (SRTM) DEM and a DEM obtained from stereo images are used in georeferencing.