Object based images Vexcel UltraCam D analysis to detect residential complexes in the municipalities of Pereira and Dosquebradas with the purpose of cadastral pre-census of IGAC

Abstract

This research presents an object - based analysis to detect residential complexes on three study areas in the municipalities of Pereira and Dosquebradas (Department of Risaralda) that have had an important urban development during the period 2005-2014, mainly residential complexes. The analysis was approached from an a priori knowledge perspective of the study areas and under a top-down processing strategy from which the segmentation of images taken on January 29 and May 12, 2015 by the sensor.

Airborne Vexcel UltraCam D of the Agustín Codazzi Geographic Institute (IGAC). During the investigation parameters of spectral, geometric, texture and context conditions were identified, which allowed to distinguish residential complexes of the other objects present in the images. A total of 251 images (stereoscopic pairs) were processed from which digital surface models (MDS) were derived from the study areas, on which different slope filters and imperfection removal were applied in order to obtain digital models of (MDT), in order to know height information of objects. The algorithm of a linear empirical model was used for radiometric calibration of the images, which required spectral signatures of different coverages such as: bare soil, swimming pools, vegetation, grass and anthropic elements (asbestos, clay, Spanish, fiber cement, zinc, thermo acoustics), among others, achieving an accuracy in the classification of residential complexes of 82.85%.