METHODOLOGY FOR THE EXTRACTION OF HOMOLOGOUS POINTS FROM A DEM/DSM TO EVALUATE THE RELATIVE POSITIONAL ACCURACY

Afonso De Paula Dos Santos,Dalto Domingos Rodrigues,Nilcilene Das Graças Medeiros,Aluir Porfírio Dal Poz,Gérson Rodrigues Dos Santos,Paulo César Emiliano

doi:10.1590/s1982-21702020000200007

Afonso De Paula Dos Santos, Dalto Domingos Rodrigues + Show 4 more

Open Access

https://doi.org/10.1590/s1982-21702020000200007

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Abstract

This work presents a new methodology for extracting 3D homologous points from a DEM/DSM for relative evaluation of positional accuracies, from terrain features such as ridgelines and hydrography. Firstly, it extracts 3D intersection points between the linear features and then it performs a selection of these homologous points. A discussion regarding the spatial resolution effect of the DEM/DSM on the proposed methodology is carried out. As case study, the planimetric and altimetric positional accuracies evaluation of SRTM (X-band) and Aster GDEM (version 2) DSMs was conducted using, as reference, a DSM obtained via photogrammetry. The SRTM and Aster GDEM (version 2) DSMs showed similar classifications, that is, Class A for the altimetry and Class B for the planimetry at the 1:100,000 scale, according to the Brazilian technical standard of positional accuracy.

Highlights

The growing demand for all sorts of spatial data has enlivened the world cartographic market
One of the digital surface models (DSMs) evaluated in this work is the X-band Shuttle Radar Topography Mission (SRTM-X) obtained during the month of February, 2000 throughout a spatial mission operated by the National Aeronautics and Space Administration (NASA) in conjunction with the USA Department of Defense represented by the National GeospatialIntelligence Agency (NGA), the German Aerospace Center (DLR) and the Italian Space Agency (ASI)
As no inconsistences were found in the process of extraction and identification of homologous points, all the studied points have been considered valid for the positional accuracy evaluation as discussed in Santos et al (2016b), no data was discarded

Summary

Introduction

The growing demand for all sorts of spatial data has enlivened the world cartographic market. This demand includes the availability of 2D information (i.e., a planimetric location or XY data) and a significant rise of 3D information (i.e., 3-dimensional location or XYZ data). This expanding interest has improved the production of digital elevation models (DEMs) and digital surface models (DSMs). Positional accuracy is the most widely studied element on literature (Ariza & Atkinson, 2008; Santos et al, 2016b)

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