Accuracy in Forest Covered Areas

To achieve 20cm survey accuracy, PhotoSat needs approximately 10 ground survey control points per 100km² of survey area.

PhotoSat routinely produces survey data accurate to 20cm in elevation on mine sites and oil and gas projects.

PhotoSat surveying using no ground survey points produces 20 cm relative and 3m global survey accuracy

PhotoSat applies a number of corrections to the stereo satellite photos prior to applying the ground survey data. These preliminary corrections usually bring the relative PhotoSat survey accuracy to 20cm in elevation over horizontal distances of 10km. The global accuracy prior to applying ground survey data is usually better than 3m in x, y and z.

PhotoSat processing using ten ground survey points per 100km2 produce better than 20cm survey accuracy

PhotoSat routinely achieves better then 20cm absolute survey accuracy using stereo WorldView-1, 2 or 3 satellite photos and Pleiades 1A and 1B Satellite photos when using ten ground survey points per 100 km2. Two examples are shown below.

PhotoSat absolute survey accuracy of 30cm is achieved using three ground survey points per 100km2. This is discussed in the 30cm accuracy page. Better than 15cm survey accuracy is achieved with 100 ground survey points per 100km2. This is discussed in the 15cm accuracy page

WorldView-2 PhotoSat survey over the 88 km2 California test area using eight survey points to achieve elevation surveying accuracy of 15cm RMSE. Accuracy checked with 7,414 check points.

WorldView-2PhotoSat survey over 100km2 of the Eritrea test area using ten survey points to achieve an elevation accuracy of 13cm RMSE. Accuracy checked with 621 check points.