Overlap and Sidelap Definition

The aircraft is moving forward. The overlap of the photos in the direction of travel is termed overlap. Increasing the overlap is as simple as having the camera take photos at a faster rate. With the Inspire using DroneDeploy and other similar set ups the aircraft will fly as fast as possible and the photos will be taken at the correct spacing. If a higher overlap is requested and the camera cannot cycle fast enough some mission planners will automatically slow down its forward speed to accommodate the camera.

Fixed wing aircraft have a lot less flexibility to fly slowly because they cannot fly near their stall speed. Fixed wing sUAS usually fly about 5 – 10 knots faster than their stall speed. This is so that if they are flying into a headwind (gust) at stall speed (the slowest speed they can fly to maintain flight) and the gust stops, the airplane doesn’t stall. Most airplanes are set up so that if they do stall the nose falls and the plane quickly picks speed up again and begins flying. However, it is better to avoid stalls because the aircraft will likely be blown off course and will definitely lose altitude. Once the autopilot recognizes this it will throttle up and bank to get back on course. These changes in attitude and pitch result in inconsistent imagery. 6-5