Obtención de geoinformación a partir de la cámara digital no métrica NIKON DH1.

Abstract

The Pacific Contamination Control Center, CCCP, developed and implemented a methodology to capture space data from airborne platforms with the use of a CCD sensor (Charge Coupled Device). The methodological process includes the design and elaboration of a mechanical device of support, which was assembled to ensure the orthogonality of the camera's lens with respect to land, on board Colombian Army air platforms, during flight, and adapting hardware and specific software to support intercommunication between the GPS, the PC and the CCD, to obtain real time controUed photos. In order to obtain better accuracy, the photos were georeferenced from a differential satellital correction using WAAS 's (WideArea Augmentation System) free service. This system allows obtaining geographical coordinates of the main point of the picture referenced in WGS 84, reducing the necessary photocontrol to apply colinearity equations. Photos are then taken through processes such as calibration of sensor in function of the focal distance of the camera and adjustment by the mínimum square method to reduce radial distortion of de lens. The first photos were used to calíbrate the system (capture, georeference and calibration of the sensor). Based on the results obtained during the experimentation phase, a flight pattern was designed over the municipality of Tumaco, controlling the flight height and the speed of the air platform (Huey helicopters), as well as the time of exposure, keeping a transversal and longitudinal overlap of 60% and 25% respectively in each exposure. As main result a panoramic view was obtained with an accuracy expected byinvestigators, of the coastal border of Tumaco2, useful to DIMAR in the process of generating and updating cartography, or for any entity that has an interest in obtaining information of this región of the country. Another potential use of this investigation is based on the sharpness of the information captured by the sensor; transforming this product, into a military tool, if advantage is taken of the space resolution and the combination of different spectral ranges of the photos obtained.