Skeye was recently awarded the publically tendered project for the creation of aerial photographs to scale (orthophoto mosaics) of over 400 kilometers of secundair roads and canals in the Netherlands for the provisie of South Holland. Current regulations in the Netherlands do not permit a commercial drone flight closer than 150 meters from these roads. In addition the roads frequently cross heavily build up areas and regulated airspace around Rotterdam Airport.
To overcome these problems, Skeye choose to use our own in house developed PhotoEye system from a manned aircraft. This system makes use of a consumer grade camera in conjunction with flight software that will instruct the pilot to fly along specific lines. The camera will trigger at predefined points and record the position. For this project Skeye used the brand new Canon 5Ds with 50 Megapixels.
The requirements of the Province with respect to resolution and accuracy were very high. The specifications stated that the maximum resolution (GSD) was to be 4 cm and the average planimetric error (X,Y at 1 sigma) no more than 4 cm. To be able to achieve these specifications Skeye opted for a resolution of 3 cm during collection. In addition a very large number of ground control points were installed as well as verification points. These verification points are used by Skeye to check the end products after data processing. In all over 1000 points were measured using RTK GPS. After processing the results it turned out that the required accuracies were easily obtained. The average planimetric error was no more than 2cm with a standard deviation of 2 cm.
Sample data of the N 467 road in the province of South Holland. This data can also be viewed in a separate full size window through this link.