Use of Airborne On-the-Fly Kinematic GPS Data for Photogrammetric Mapping

摘要

Aerial triangulation procedure is routinely used forrnextension of sparsely distributed ground control forrnphotogrammetric mapping. The use of camera positionsrnderived through airborne GPS data collected during flightrnmissions significantly reduces the need for ground surveyrnoperations. The position of the aerial camera,rngeometrically linked to an aircraft mounted antenna, isrndetermined through differential kinematic data post-processedrnwith reference to a known ground base station.rnThe camera locations are usually needed with a precisionrnbetter than 10cm for large-scale engineering mapping. Inrnorder to ensure the correct resolution of integerrnambiguities to meet this precision, the collection of GPSrndata starts before take off while the aircraft is stationary.rnThe need for maintaining continuous lock on 5 or morernsatellites during the entire mission places seriousrnrestrictions on the pilot for banking and turningrnmaneuvers. Recent advancements in the GPS hardwarernand post-processing software enabling the resolution ofrnambiguities on-the-fly (OTF) offer an attractivernalternative to eliminate flying restrictions. However,rnthere is always the possibility that OTF ambiguities may