In a vertical aerial photograph, the principal point is the point where the:
Correct answer: B. Camera optical axis meets the photograph
- A. Ground nadir is always marked
- B. Camera optical axis meets the photograph
- C. Horizon line crosses the photograph
- D. Aircraft flight path meets the ground
Explanation
The principal point is the intersection of the camera's optical axis with the photograph. It is a key reference point in photogrammetric measurements and is commonly identified using fiducial marks.
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Surveying covers measurement of distances, angles and elevations, traversing, levelling, contouring, plane table work, theodolites, total stations and basic photogrammetry. It includes error adjustment, coordinate calculations, area and volume determination, and the distinction between accuracy and precision, as well as between temporary and permanent adjustments.
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