User Manual UX11
60 m
20°
45 m
-40 m
-130 m
50 m
Ab
ort
Ab
ort
Ab
ort
15°
4.3 GSD and height
The GSD (ground sample distance) specifies the distance on the ground represented by the pixel of
a captured image. It depends on the camera sensor’s pixel size and lens focal length. The smaller the
GSD value, the more detailed the images. The GSD and the height at which the aircraft flies are linked.
The higher the aircraft flies, the larger the distance on the ground represented by each pixel in the
images.
4.4 Image overlap
The percentage of image overlap allows processing software to refine for errors in the position and
orientation of the aerial images.
Delair recommends having a forward overlap of 80% and a sidewards overlap of 60% which gives the
most accurate results while minimizing flight and processing time.
An increase of the overlap may be beneficial when flying over terrain that does not have many
identifiable features in the images that can be used as tie points for the image adjustment. Examples
are dense tree canopy, bodies of water, or large areas of sand or snow.
Image overlap also varies with changing terrain elevation and features.
Delair
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| www.delair.aero
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