DETERMINATION OF ALTITUDE CORRECTION FACTORS FOR DIGITAL ELEVATION MODEL

Abstract

Using Digital Elevation Models (DEMs) imparts a necessity for checking its accuracy and precision, due to their variety of applications, whether in private or public projects. For this purpose, understanding the contribution of geodesy as a basic science, oriented towards the results earth measurements and calculations, is revealed. Therefore, vertical accuracy this study aims determinate from assignment and altimetric comparison between 4 geometric levelling considering 3 open source DEMs: SRTM, ASTER GDEM and PALSAR. Also, worlds standard geopotential models (EGM-96 and EGM-2008) were analyzed to verify specific vertical reference system adjustment for each model. Then, the objective proposed in the present work describes a methodology for determination of local altitudinal correction factors, conditioned by the use of an observation equation, which allows determining more probable values, based on the principle of Least Squares, this means, the equation was implemented, and factors were obtained to correct the vertical altimeter accuracy. Regarding the analysis, this was carried out based on a set of 132 samples, which are located close to a 116 km linear trajectory.