Geodata acquisition is a favourite practical course.
The first task was collecting a data of infrastructure within the area of interest 500*500 m using a Real-Time GNSS device. Then collected data were processed in Pathfinder Office.
The main objective was to generate Digital Surface Model, mosaicked orthophoto and law density point cloud, using 11 areal imagery of Salzburg city. Firstly we measured ground control points (GCPs) with GNSS using RTK. After measurements these GCPs were transformed into local (austrian) coordinate system as MGI BMN 31 (Bundesmeldenetz).
DSM extraction was processed within ERDAS IMAGINE commercial software, where main steps are:
- creating photogrammetry model
- defining camera parameters: exterior and interior orientation
- measurement of Ground control points, Tie point generation
- aerial triangulation
Result of DSM generation:
DSM needed for generation of mosaiced orthophoto: