You have been asked by a mining company to fly an aerial survey for them.The area to be imaged is a 30 km (E-W) by 40 km (N-S) rectangle. The mining company would like the aerial digital images to be captured at 10 cm ground sample distance (GSD) with a Vexcel Ultracam X digital mapping camera [sensor size: 6 cm (H) x 10 cm (W), 9400 (H) x 14400 (W) pixels]. The focal length of the camera is 104 mm. The aerial images should have an average forward overlap of 60% and an average sidelap of 30%.

The number of required flight lines is a product of the required amount of sidelap, the lateral distance covered by a single image (swath width) and the total width of the rectangular area to be imaged. Assuming an average sidelap of 30% (or 0.3), the lateral gain from one line to another is 70% (or 0.7) of the swath width of an image.

Swath Width = Ground Sample Distance X Image Width Lateral Gain = 0.70 x Swath WidthThe number of intervals between flight lines is found by dividing the total width of the rectangle by the lateral gain. If the number of intervals is a fraction, then the number of flight lines is the next largest integer. The number of intervals is rounded down to the closest integer. Total Width of Rectangle # of Intervals = Lateral Gain # of Flight Lines = # of Intervals (+1 If # of intervals is a fraction)