Comparación entre modelos digitales de elevación obtenidos de Sentinel-1 y modelo obtenido con LiDAR mediante puntos de control RTK (real time kinematics) en el área urbana del cantón Santa Isabel

Abstract

In the present work, a comparative study was carried out between a digital elevation model generated through LiDAR and Sentinel-1 models, obtained through interferometry applying different resampling methods, corresponding to the year 2021. The study area corresponds to the urban area of the Canton Santa Isabel belonging to the province of Azuay. The study was based on determining the differences between the data obtained through the Sentinel-1 active model and the LiDAR model with the RTK reference points, to determine the feasibility of these models according to their costs. To obtain the satellite images, the Alaska Satellite Facility platform was used, these images had a perpendicular base of 27 m and a temporal period of 12 days, for their processing the InSAR technique was used with the use of SNAP software and geographic information systems. Of the models compared, the DEM corresponding to LiDAR presented a root mean square error (RMSE) value of 0.15 m, while, of the models obtained with interferometry, the DEM with the lowest RMSE value corresponds to the one generated by bicubic resampling, this being 40.01 m and the highest RMSE value being the model belonging to the nearest neighbor resampling with an error of 511 m. According to the results obtained, it was determined that the use of LiDAR for studies or projects that require an elevation model with greater precision is more feasible. This is because the models obtained by interferometry differ significantly from the RTK reference values.