Skeye BV secured a contract to survey a nature reserve in the Netherlands using aerial photography. This nature reserve, called Noordwaard is an area of around 4450 ha, or 6000 football fields that lies in between the major rivers in the Netherlands. The Noordwaard area was previously a polder lying below the level of the adjoining rivers. The area is now remodelled so as to allow the water to flow freely through the area in times of high water.
Skeye carried out the project using our in house developed PhotoEye system. This system makes it possible to fly with a manned aircraft over predefined lines and to capture aerial images at predefined locations. The location of these photographs is accurately logged using GPS. The images are taken in such a manner as to create a certain percentage overlap. In the overlaps of around 6000 images the heights of each photo pixel was calculated as well as its position. From this point cloud a very accurate and detailed 3D digital terrain model was created with a Z accuracy of around 75 mm.
Besides the Digital Terrain Model all the individual images were stitched together whilst removing the distortions created by height, scale and colour differences. In the resulting orthophoto mosaic the user can directly measure distances and calculate areas.