Comparison Between Absolute and Relative Positional Accuracy Assessment - A Case Study Applied to Digital Elevation Models

Abstract

This paper presents a comparative study between the absolute and relative methods for altimetric positional accuracy of Digital Elevation Models (DEM). For the theoretical basis of this research, the definitions of accuracy (exactness) and precision, as well the concepts related to absolute and relative positional accuracy were explored. In the case study, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Shuttle Radar Topography Mission (SRTM) DEM were used. In the analysis of the absolute accuracy, 6,568 ground control points from GNSS orbital survey were used, collected through relative-static method. In the relative accuracy, it was used as reference DEM with spatial resolution of 5 meters generated by stereophotogrammetrical process for the Mapping Project of Bahia (Brazil). It was concluded that, once the accuracy of the reference DEM is better than the other two evaluated DEM, the results of the classification for the PEC-PCD for the relative evaluation are equal to or better than the absolute evaluation results, with the advantage to being able to verify the pixel population of the evaluated models, which makes it possible to identify outliers, distortions and displacements, including delimiting regions, which is much less likely with a limited set of control points.

Optimized Determination of 3d Coordinates in the Survey of Inaccessible Points of Buildings - Example of Application Implemented in Free Software

“…In this work, only the precision of the adjustment was evaluated, considering the target was an inaccessible point, however, future studies may apply the method of minimum distances to a known coordinate point, in order to also evaluate the absolute accuracy of the method (França et al, 2019).…”

“…The determination of object-points of building structures using the method presented in this work, also contributes to the study and quality control of topographic surveys performed with drones as well as control of the Digital Surface Model obtained with LiDAR data in urban environments. In these cases, a methodology for evaluating both planimetric and altimetric accuracy is discussed in Cintra & Nero (2015), Nero et al (2017), França & Silva (2018 and França et al (2019).…”

A influência do polo industrial de Camaçari na cartografia sob a ótica da reambulação

“…Os insumos de imagens recebidos para este trabalho foram: a carta topográfica matricial na escala de 1:100.000 (SALVADOR-SD-24-X-A-VI) e ortofotos coloridas com GSD 80 cm, precisão na escala de 1:10.000 (PEC Classe A) oriunda de voo fotogramétrico realizado em 2010 (FRANÇA et al, 2019 Além desses insumos, recebidos da coordenação técnica do projeto, também foram utilizados outros insumos adquiridos durante a reambulação, provenientes de órgãos públicos ou empresas idôneas, tais quais: Carta da Região Metropolitana de Salvador (RMS) e suas periferias na escala de 1:100.000 de 1996, Carta de Camaçari na escala de 1:5.000 de 1995, Cartas 099000, 098000, 087000, 086000, 074000, 073000, do Sistema Cartográfico da Região Metropolitana de Salvador (SICAR/RMS) na escala de 1:10.000 de 1976, todas elaboradas pela Companhia de Desenvolvimento da Região Metropolitana de Salvador (CONDER), Mosaico de fotografias aéreas de Camaçari com GSD 10 cm, oriunda de voo fotogramétrico realizado em 2017 e plantas das indústrias em arquivos com extensão nos formatos *pdf e *dwg.…”

Integração Sistêmica Entre Sociedade E Ambiente: Um Estudo Do Baixo Rio Jundiaí No Município De Indaiatuba Sp

“…Accordingly to França and Ferreira da Silva (2018) due to a large number of nonmapping specialists and different methods more discussions are emerging about the reliability of geospatial data. So the following quality categories about these data must be evaluated: completeness logical consistency positional accuracy temporal accuracy and thematic accuracy (França et al 2017França et al 2019.…”