Guides
Straight answers to the questions surveyors ask, with the sources behind them.
How many ground control points does a drone survey need?
What ASPRS Edition 2 and drone photogrammetry research say about how many ground control points a drone survey needs and how to spread them across a site.
How many checkpoints does ASPRS Edition 2 ask for?
How the planner works out checkpoint counts from project area for a checkpoint layout designed to ASPRS Edition 2, and when fewer checkpoints are allowed on small sites.
How far apart should ground control points be for your flight height?
How far apart to space ground control points for your drone's flight height, and how the planner spreads them across a site.
GCPs and checkpoints: what is the difference?
Why drone photogrammetry surveys need both ground control points to tie down the block and independent checkpoints to test the finished model.
Why are checkpoints kept away from ground control points?
Why photogrammetric error grows with distance from ground control points, and how the planner keeps checkpoints clear of GCPs and vertical obstacles.
How do you use the plan files on an RTK controller?
How to load the separate GCP and checkpoint CSV files onto an RTK controller, walk each route in ID order, and survey the targets where they land on site.