Airborne LiDAR Compliance and Quality Assurance Tool (ComQAT)
ComQAT
Accuracy of Control Network Control Density Pass/Fail minimum points per square kilometre Score density of points per square kilometre (e) e = n / a where, a = project area (km 2 ) n = number of CPs Survey AreaGround Control Density Requirement km 2 ≥5 CPs + minimum 3 GCPs 100 – 400km 2 ≥20 CPs + minimum 5 GCPs ≥400km 2 20 CPs + 1 CP for every 50km 2 over 400km 2 + minimum 5 GCPs ScorePoint Density 1 - Poor Weak Average Good Strong≥0.02
Accuracy of Control Network Control Distribution spread of points across the project area how well points cover extremities of project whether points are weighted to one side of the project Average distribution Ideal distribution Weak distribution Poor distribution
Absolute Vertical Accuracy Flatness Rating / Openness Rating Flatness: Height difference ground point to control point (cm) Openness: % non- ground points within 10m of control point Poor>8>50 Weak Average Good Strong<2<5 Rate ‘flatness’ & ‘openness’ of area around each control point to determine suitability
Visual Checks