Issue link: https://geospatial.trimble.com/en/resources/i/1397716
Schiphol Airport in The Netherlands averages about 1,350 take offs and landings per day. With that much volume, flight control is strict, making it difficult to collect spatial data near the crowded air space. As part of an annual aerial survey, one Swiss-German geospatial company combined a smart flight plan and robust photogrammetry software to successfully deliver high-precision data and secure repeat flights in the future. overview Location THE NETHERLANDS TRANSFORMING THE WAY THE WORLD WORKS TRANSFORMING THE WAY THE WORLD WORKS Since 2009, the Information & Coordination Centre (ICC) of the Schiphol Region has conducted an aerial photo campaign to provide its government-affiliated members with access to up-to-date high-resolution aerial photographs. The program's total area of interest (AOI) can change yearly, but the delivery requirements are always the same: seamless orthomosaics with a ground sample distance (GSD) of 4cm or less. In 2016 BSF Swissphoto received a two-year contract to survey one of the AOIs under the ICC's program. Proving its capabilities, it was then awarded a subsequent contract for the same 900-sq-km area for 2019 and 2020. For the 2019 campaign, BSF Swissphoto's AOI included 17 ICC municipal territories in the northern part of Schiphol, each of which required its own seamless orthomosaic. The orthomosaic had to be precisely color-balanced— no dark shadows or excessively bright spots — geometrically accurate, completely clear with distinct contrast, and aesthetically pleasing. Adding to the exacting requirements, staff had to triangulate and deliver the final processed images within seven weeks; and all the final datasets had to be delivered in only 11 weeks from image acquisition. The flight plan was developed with the highest post- processing efficiency in mind. To provide accurate control, a team laid out 164 ground control points (GCPs) with a horizontal accuracy of better than 3 cm. After 30 hours of flying, they had collected 30,000 images that were processed along with the aircraft trajectory data. The images and GCPs were imported into Trimble Inpho's MATCH-AT georeferencing module to automatically triangulate the images. "The automatic triangulation and tie-point identification capabilities in Inpho are very good and give us the