PS Photogrammetry & Remote Sensing

Question 1

The principal point in aerial photogrammetry is best defined as:

Accepted Answer

The foot of the perpendicular from the lens center to the image plane

Answer

The principal point is where the optical axis (perpendicular from the camera's front nodal point) intersects the image plane, defining the geometric center of the photograph.

Question 2

Relief displacement in an aerial photograph causes elevated objects to appear:

Accepted Answer

Displaced radially outward from the principal point

Answer

Relief displacement shifts elevated objects radially outward from the principal point—the greater the object's height and distance from photo center, the more pronounced the outward displacement.

Question 3

The photo scale at a ground point with elevation h above datum, where f is focal length and H is flying height above datum, is:

Accepted Answer

f / (H - h)

Answer

Photo scale at any ground point equals f/(H−h); terrain at higher elevation reduces the effective flying height above ground, producing a larger-scale image for that location.

Question 4

The base-to-height (B/H) ratio in aerial stereoscopy is defined as:

Accepted Answer

The ratio of air base distance between exposure stations to flying height, controlling stereo height accuracy

Answer

The B/H ratio (air base divided by flying height) governs the geometry of stereo height determination—a larger B/H improves vertical accuracy but increases relief displacement.

Question 5

In aerial photography, a standard 60% forward overlap (end lap) is maintained primarily to:

Accepted Answer

Ensure complete stereoscopic coverage so every ground point appears in at least two consecutive photographs

Answer

A 60% forward overlap ensures every ground point is covered by at least two adjacent photos along the strip, creating the stereo pairs required for 3D measurement and height determination.

(PS) Professional Licensed Surveyor Practice Test

(PS) Professional Licensed Surveyor Practice Test

PS Photogrammetry & Remote Sensing