Numerous satellites circle the earth, emitting signals that travel to the surface.
The time they take to reach the earth can be used to determine the satellites' distance from the earth. By picking up signals emitted from at least four satellites, it is possible to pinpoint your position on the earth and thereby establish coordinates for geographic features you have located. We use differential correction to ensure the accuracy of our maps. Differential correction is a method of eliminating positional error by utilising corrected data provided by precisely located base stations. This enables sub-metre accuracy in most instances.