MIVIS image geocoding experience on merging position attitude system data and public domain GPS stream (ASI-GeoDAF)

Abstract

The use of airborne scanners involves geo-referencing problems, which are difficult because of the need to know the exact platform position and attitude for each scan line. The errors of the onboard navigation system are normally corrected using ground control point on the image. This post-processing correction procedure is too long in case of multiple flight campaigns, and besides it implies the need to have available 1:10000 orthophotoimages or maps in digital format. To optimize the above procedure a new method to correct MIVIS navigational data in the post-processing phase has been implemented. The procedure takes into consideration the GPS stream in Rinex format of common knowledge and findable on the web, acquired at the ground stations of the Geodetic Data Archiving Facilities provided by ASI. The application of this correction entails the assumption that the environmental variables affecting both onboard and geodetic GPS equally affect the position measurements. The airborne data correction was carried out merging the two data sets (onboard and ground station GPS) to achieve a more precise aircraft trajectory. The present study compares the geo-coded images obtained by means of the two post-processing methods.