Orientation, orthorectification, terrain and city modeling from Cartosat-1 stereo imagery: preliminary results in the first phase of ISPRS-ISRO C-SAP

CARTOSAT-1, launched in May 2005, is basically a stereo mission, as it is equipped with two cameras onboard, namely Aft and Fore, tilted along track by -5° and +26° respectively, allowing the acquisition of stereo data with a resolution of 2.5 m. The Institute "Area di Geodesia e Geomatica" at Sapienza Universita di Roma, Eurimage S.p.A. and the former CyberCity AG participated at the ISPRS-ISRO Cartosat-1 Scientific Assessment Programme (C-SAP), in order to investigate the generation of Digital Surface Models (DSMs) from Cartosat-1 stereo scenes. The paper describes the work carried out during the summer of 2006, on the stereopair belonging to the test field called TS-8, acquired on 8th June 2005 over the city of Rome, Italy. The processing included the sensor orientation, Digital Surface Model (DSM) generation, orthoimage production and 3D features extraction. For the evaluation of the DSM, orthophoto and 3D feature accuracy, a large scale 3D map (1:2′000) was used.