Evaluation of the accuracy of the Structure from Motion technique applied to Photogrammetric Mapping of Corridors

Abstract

The advantages offered by the use of RPA technology combined with the algorithms implemented by the SfM technique and its variants have made Photogrammetry supported by RPA and SfM an economical, fast and widely used solution in various branches of Engineering. Despite many studies on the accuracy achieved in digital cartographic products generated through these technologies, little is discussed about the case of corridors. In this context, the objective of this work is to investigate the positional accuracy achieved in the mapping of a 1.3 km long corridor through the adoption of different amounts of control points and different amounts of lanes. Accuracy assessment was performed based on the Mean Square Error (NDE) values of the checkpoints and trend analysis. The experiments showed that the adoption of control points positioned every five and ten photogrammetric bases can achieve accuracy between 2-2.6 GSD and eliminate planimetric and altimetric statistical trends in the RMSE values of the checkpoints that adopt two or three bands. In addition, the experiments performed showed that increasing the number of bands does not necessarily imply a decrease in the NDE values of checkpoint discrepancies.