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

• Main Author: Santos, Afonso de Paula dos
• Publication Date: 2020
• Other Authors: Medeiros, Nilcilene das Gracas, Dal Poz, Aluir Porfirio [UNESP], Santos, Gerson Rodrigues, Rodrigues, Dalto Domingos, Emiliano, Paulo Cesar
• Format: Article
• Language: eng
• Source: Repositório Institucional da UNESP
• Download full: http://dx.doi.org/10.1590/s1982-21702020000200007; http://hdl.handle.net/11449/196955
• topic: positional accuracy; DSM; DEM; homologous point extraction; spatial data quality

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.