An approach for the precise DEM generation in urban environments using multi-GNSS

Abstract

Digital Elevation Models (DEMs) of large areas are usually prepared by satellite images and airborne Light Detection and Ranging (LiDAR). However, obstacles due to urban canyon and others negatively affect the precision of DEM generated through the airborne platform. Global Navigation Satellite System networks, utilizing Real-Time Kinematic networks (NRTK), or post-processing kinematic (PPK), play an active role in supporting applications requiring high positioning accuracies. The principal objective of this research is to generate urban DEM using multi-GNSS. The methodology comprises collecting and processing multi-GNSS data by PPK technique, automatic filtering of processed data for outliers in elevation and density, and DEM generation. The PPK resulted in 71.92% fixed solutions. Spatial outlier filtering algorithm (SOFA) detected the outliers with 99.92% overall accuracy. A decimeter level precise DEM is generated. Overall, the present research strengthens the scope of multi-GNSS, especially in the application, which requires high accuracy.