GPS-CONTROLLED STRIP TRIANGULATION USING GEOMETRIC CONSTRAINTS OF MAN-MADE STRUCTURES

Conventional block adjustments have been widely used to determine both photogrammetric ground point coordinates and the exterior orientation parameters of photography for mapping purposes. Ground control points are necessary to relate the image coordinate system to the object spa ce coordinate system and to ensure the geometric stability of the conv entional photogrammetric block as well as to control error propagation . The major impact of cost and time consumption for ground control est ablishment on any mapping project is the primary reason that photogram metrists have been looking for a replacement for ground control by aux iliary data (e.g., Global Positioning System). This paper describes a new technique for GPS-controlled single strip triangulation using geom etric constraints of man-made structures (e.g., high voltage towers, h igh rise buildings) located approximately along the flight line. The e ffects of the different GPS measurement accuracies were also investiga ted. Both the precision and the reliability analyses of the GPS bundle strip adjustment with these constraints were carried out on simulated and real data.