Photogrammetry MCQ with answer and solution

Concept

Scale of an aerial photograph

Formula

Scale = f / H = (photo distance) / (ground distance)

Step-by-step solution

1. Photo distance 6 cm for a ground distance of 1 km = 1,00,000 cm. 2. Scale = 6 / 100000 = 1 / 16667. 3. f/H = 1/16667, so H = 0.15 m × 16667 = 2500 m.

Explanation

For a vertical photograph of flat terrain, scale = focal length ÷ flying height above ground. The scale is found from a known ground distance and its length on the photograph.

Shortcut

H = f × (ground length ÷ photo length) = 0.15 × (1000/0.06) = 2500 m.

Common mistake

Converting units wrongly (mm, cm, m, km).