Tag Archive
5 articles on checkpoints. Field-tested methodology from a GIS scientist with M.S. GIS, FAA Part 107, and 10+ years of geospatial work.
RTK alone produces 2–5 cm horizontal but 5–15 cm vertical bias. Why GCPs still matter, when checkpoint-only works, and the bowling/doming failure mode.
GCP residuals measure fit, not accuracy. Drone survey checkpoints provide independent validation. How to set them up in Pix4D, Metashape, WebODM.
Four positioning tiers for drone surveys: GPS, RTK/PPK, GCPs, and full RTK+GCPs+checkpoints. Match accuracy to the job — not every project needs the top tier.
Real drone survey accuracy in 2026: ±2–5 cm horizontal, ±3–12 cm vertical typical. RMSE vs CE90 vs LE90 explained, ASPRS classes, 5 red flags in any quality report.
How many ground control points does a drone survey need? 5 GCPs for under 5 acres, 8–12 for 50–500. Distribution beats density — and always include independent checkpoints.
Free download: The Complete Drone Mapping Workflow Guide — 30+ pages of field-tested methodology.
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