PIXEL GEOLOCATION ALGORITHM FOR SATELLITE SCANNER DATA

This work describes the geolocation determination of remote sensing data, utilizing a satellite configuration that supports a sensor designed to scan the surface of the Earth and it presents mathematical algorithm for determining the position of field scanning satellite records, especially those of imaging. In this paper, it is presented a relationship that give us the coordinates of the point of intersection of the line of sight scanning system and the Earth's surface as a function of: terrestrial ellipsoid surface, satellite position, satellite velocity, satellite attitude (spatial situation) and orientation of the scanner. The input parameters include the orbital state and attitude information of the satellite and the look vector of the remote sensing sensor. The process for calculating the pixel geolocation (geodetic latitude and longitude) starts with the calculation of the Instantaneous Field-Of-View (IFOV) matrix in sensor coordinates. Then, several rotations are required to obtain the IFOV in the Earth Centered Inertial (ECI) coordinate system. First there is the sensor-to-satellite rotation that obtains the IFOV relative to the satellite. Next there is the satellite-to-orbital (geodetic nadir pointing) rotation that obtains the IFOV relative to the path of the satellite. The transformation between the scan pixel and the ECEF pixel is expressed in terms of a series of consecutive matrix transformations applied to the line of sight vector. Finally, for any scan pixel, we obtain ECEF coordinates (by intersection of the IFOV with the ellipsoid used to model Earth) and then geodetic coordinates (geodetic longitude and latitude).