Data collection description
You can use your own ground control or access the largest commercially available ground control data set - GCPArchive.
Ground Control Collection
The foundation of CompassData’s business is GPS surveying. We currently have an archive of over 36,000 Ground Control Points (GCPs) around the world.
These points have been collected for all types of projects and for a variety of customers. We regularly perform survey work for both imagery and LiDAR collects to sub 5 cm x, y, z requirements. Each of our GCPs is provided to the customer with all supporting metadata, context photos, accuracy reports and station diagrams. Increase accuracy and save time and money by designing your project area to coincide with archive GCPs.
The GCPs in the CompassData archive have all passed rigorous quality-control procedures. The accuracy of the GCPs are defined as follows;
Quality-1: 1cm – 10cm horizontal accuracy, 3cm – 10cm vertical accuracy
Quality-2: 10cm - 20cm horizontal accuracy, 10cm - 20cm vertical accuracy
Quality-3: 20cm - 50cm horizontal accuracy, 20cm - 75cm vertical accuracy
Quality-4: 50cm – 70cm horizontal accuracy, 75cm – 1.25m vertical accuracy
Quality-5: 70cm – 2.5m horizontal accuracy, 1.25m – 5m vertical accuracy