Ortho & LiDAR. Accuracy Assessment. Mike Tully President & CEO, Aerial Services, Inc. Cedar Falls, Iowa. FAIL. George Washington Bridge, NY. FAIL. FAIL. FAIL. Now What? . Take Away: Why you should care about positional accuracy !. “Intended Use”. What do you mean by
President & CEO, Aerial Services, Inc.
Cedar Falls, Iowa
Why you should care
about positional accuracy!
Simple & Sweet
NMAS 2’ Contours requires ½ Contour Interval = 1.0’ Accuracy.
NSSDA with 95% Confidence requires 1 RMSE of 0.61’
Error in Z
Lidar (points/sq m)
ASPRS [Draft] Accuracy Standards for Digital Geospatial Data, 2012
Includes a new high accuracy level “X”
Class IIA = USGS minimum vertical accuracy (unclassified lidar)
Ortho & Lidar
Visual inspection of hydro-flattening seems to be
predominant quality metric. There are BETTER ways!
SIS Topo Analyst™
Co-Registered LiDAR and Ortho accuracies are reported.
Point Density Plots
Water Voids / Holes
Relative Accuracy (RMSD)
Control Point Errors
Automated QA / Verification