All aerial photography and mapping systems suffer the same
trade-off - photographs with a very wide field of view (FOV)
increase mapping accuracies, due to the wide stereo angles that
are created between overlapping photos. Unfortunately, the same
wide field of view reduces image resolution (GSD). This is a
serious drawback, because the market constantly demands higher
resolutions. In most large format systems, this trade-off has
resulted in a fine balance between field of view and resolution
- on average, about 100mm of focal length, which in turn
dictates the flight altitude that is required for any image
resolution. This focal length is good for capturing medium-sized
areas in resolutions of 25-50 cm. However, when 5-15 cm
resolution is mandated, or when the area is very large, many
flight days are required to complete the project. This is very
inefficient because it increases the cost as well as the risk,
due to weather constraints and aviation logistics. Since focal
length dictates flight altitude for a