Analysis of homogeneity and isotropy of spatial uncertainty by means of GPS kinematic check lines and circular statistics

Ángel M. Felicísimo 1, Aurora Cuartero 1 and María E. Polo 2
 1 Escuela Politécnica, Universidad de Extremadura
Avenida de la Universidad s/n, Cáceres 10071, Spain
Tel.: + 34  927 257 195; Fax: + 34 927 257 203
amfeli@unex.es; acuartero@unex.es
2 Centro Universitario de Mérida
Santa Teresa de Jornet, 38, Mérida 06800, Spain
Tel.: + 34 924 387 068; Fax: + 34 924 303 782
mepolo@unex.es

Abstract

We propose an alternative way to analyze the planimetric error with a special application to quality control of geometric corrections of satellite images. Our proposal is performed in three stages: a) the capture of check lines by kinematic GPS procedures, b) the calculation of disagreement between GPS check lines and the corresponding lineal structures (ways) extracted from images, and c) the analysis of error by means of circular statistics.  The GPS kinematic allows to obtain quickly  hundreds of check points above the ways. The automatic reconnaissance and extraction of these ways allow to calculate the error vectors due to defective overlapping between GPS data and image. A vector represents the deviation between the GPS data (true position) and the corresponding point over the image. Each vector is defined by means of its modulus and azimuth. The last step allows to check the magnitude, homogeneity and isotropy of errors.

Keywords: spatial accuracy, error analysis, uncertainty, environmental data, model

In: Caetano, M. and Painho, M. (eds). Proceedings of the 7th International Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences, 5 – 7 July 2006, Lisboa, Instituto Geográfico Português

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