GCP file settings
🕐 Read time: 3 min
Written By Clark Yuan
Last updated 4 days ago
Overview
Ground Control Point (GCP) files have their own file settings that control how they are displayed in the viewer. GCP settings are global: any change you make applies to that file for all users viewing the Project.
Unlike point clouds (3D only) and rasters (2D only), GCP files appear in both the 2D and 3D viewers automatically.
GCP file settings open in the File Information Panel, which extends from the right side of the viewer.
How to open the File Information Panel
Open a Project and enter the viewer.
Locate the Layers Panel on the left side of the viewer.
Click on a GCP file name in the Layers Panel.
✅ The File Information Panel opens on the right side of the viewer.
Display settings
Opacity
Controls how transparent or opaque the GCP pins appear in the viewer.
💡 Tip: Reducing opacity is useful when GCP icons are obscuring an area of the point cloud or raster you need to inspect. Dial down the opacity temporarily to see the data beneath without removing the GCPs from view entirely.
Designating Checkpoints
Within the File Information Panel, each individual GCP point can be designated as either a GCP or a Checkpoint.
By default, all uploaded points are treated as GCPs. To designate a point as a Checkpoint, select the point and check the Checkpoint box in the panel. The pin icon updates immediately to reflect the change:
GCPs vs. Checkpoints — key differences
Physically, GCPs and Checkpoints are identical markers placed in the field. The difference lies entirely in how they are used. While GCPs “anchor” the map, Checkpoints act as independent validation points. Checkpoints are located throughout the map but are excluded from processing and are instead used to measure the difference between the map’s calculated position and the actual measured location on the ground — the GCP Accuracy Report.
Why use GCPs? Standard drone GPS provides general positioning but lacks survey-grade precision. GCPs are essential when precise alignment to real-world coordinates matters. Common use cases include:
Surveying — land development and infrastructure projects where every centimeter of alignment counts
Volume calculations — comparing stockpile volumes across multiple captures requires high absolute accuracy to be meaningful
Client deliverables — Projects shared with engineers, planners, or regulators often require documented spatial accuracy
Why use Checkpoints? Checkpoints are excluded from the accuracy adjustment but are placed throughout the site to independently verify the result. They are valuable for:
Measuring real-world accuracy — revealing how well your data reflects actual feature positions on the ground
Identifying spatial drift — over long corridor surveys, small errors can accumulate; Checkpoints detect and quantify this
Building trust with clients — a validated accuracy report with independent Checkpoints is a professional deliverable that demonstrates rigor
ℹ️ Note: The distinction between GCPs and Checkpoints matters most when generating an accuracy report. Accuracy reports list GCPs and Checkpoints separately; mixing the two types will produce a misleading report. Designate your points correctly before attaching any accuracy documentation.
💡 Tip: As a general starting point, use a minimum of 4 GCPs distributed across your Project area, with at least 1 Checkpoint for independent validation. Your specific accuracy requirements and site conditions may call for more.
Layer Info
At the bottom of the File Information Panel, the Layer Info section displays metadata about the GCP file:
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Ground Control Point (GCP) Overview