Evaluating Quality of UAV´s Products: Study Case Uruguay
ISBN 978-85-88783-11-9
Authors
1Casanova, R.; 2Pérez, M.; 3Pampinella, V.
1Faculty of Engineering of the University of the Republic, Uruguay
2Faculty of Engineering of the University of the Republic, Uruguay
3Faculty of Engineering of the University of the Republic, Uruguay
Abstract
As the increment of applications using non-traditional photogrammetric flights has been growing up vertiginously, the need of knowing the real positional accuracy obtained on these products takes a significant place, specially to be able to certify their certain possibilities of use. For this reason, in this research, it has been made a positional quality control of a non-traditional photogrammetric product, based on an UAV flight done in Montevideo, Uruguay. The digital images were taken with a non-metric camera (Sony NEX-7) mounted on an unmanned aerial vehicle (UAV) Microdone md4-1000 and processed with the ERDAS IMAGINE 2013 software. As the average flight height was close to 100m and the covered area was about 1 ha 4000 m2, it were required four images on a flight line to obtain tridimensional coordinates from the study area. During the process, sixty-five tie points were defined to generate the stereoscopic model, 13 manual tie-points according Von Grüber’s distribution and 52 automatics tie-points. For the exterior orientation, it has been used five control points to the whole area. Those were measured by classic topographic methods, using total station and automatic level to enhance their accuracy. The quality control´s method applied was based on the National Standard for Spatial Data Accuracy to measure and report geographic data quality. In order to apply this method it was necessary to have 29 check-points, which were able to be measured topographically and photogrammetrically. Those points were signalized before the flight, to ensure they were visible on the aerial images. Complementary to check the quality, an additional relative quality control was made, considering each pair of check-points. Therefore, the research includes the analysis of residual vectors of each point´s coordinates (considering length, position and distribution in the whole study zone) and an evaluation of the restitution procedure. Finally, some suggestions are made in order to improve the results obtained on a UAV´s flight.