River lines from GVT's KML files are checked against the project sheet and the terrain, then cut into flight paths of up to 2 km of river. Every route is checked on the Digital Sky airspace map before the flying day.
The flight crew marks and surveys ground control points and checkpoints with survey-grade GNSS, so every model is tied to real coordinates and heights.
An enterprise drone flies each path at 100 m above ground, covering a 100 m wide corridor along the river, launched from a point near the middle of the path.
The same evening the data is checked for coverage and positioning, copied twice, and any gap is scheduled for a re-fly the next morning.
Each river is processed as one block: aligned on its ground control, then built into the orthomosaic, 3D model and terrain model.
Orthomosaic, 3D mesh, point cloud, surface and terrain models, contours, cross-sections, long sections, volume tables and the accuracy report.