Essential Concepts in Photogrammetry and Aerial Photography

June 2010

1. Understanding Camera Components: True Statements

Select the statement(s) that is/are true:

• The shutter is the system that regulates the light beam through the lens.
• The image compensation mechanism is located in the camera body, and its effect is more pronounced with faster films.
• In analog sensors, spectral sensitivity does not depend on the size of film grain.
• The diaphragm helps provide a uniform distribution of light from the image.

2. What is Accommodation in Optics?

Select the correct definition of accommodation:

• A psychological mechanism that gives us the perception of relief.
• A physiological mechanism that allows us to adequately focus images by adjusting the cornea.
• The process by which we obtain sharp images of objects.

3. Identifying Incorrect Definitions of Parallax

Select the response(s) that is/are incorrect relative to the definition of parallax:

• It is the difference in the retina of the two angles of convergence.
• The percentage of common ground in two consecutive snapshots.
• It is the image displacement of a point in two consecutive frames.

4. Characteristics of Aerial Photographs: Correct Statements

Select the correct answer(s):

• Nadir photographs have greater uniformity in scale than oblique photographs.
• In vertical photographs, deformation of detail is minimal.
• In low oblique photographs, the inclination of the optical axis is less than five degrees.
• Oblique photographs provide an image that closely resembles a map.

5. Photogrammetric Principles: Correct Statements

Select the correct answer(s):

• The camera's principal distance and flying height inversely affect photographic scale.
• The photographic coordinate system places its origin in the lower left corner of the picture.
• The scale of photography is a relationship between the principal and the focal distance of the camera.
• For cameras with telephoto lenses, the focal length is approximately equal to the diagonal of the picture format.

6. Relief Displacement in Photogrammetry: Key Features

Select the correct answer(s):

• The shift at the center or principal point is zero.
• A greater distance from the fiducial center point results in lower displacement.
• The greater the height of the point above the reference plane, the lower its displacement.
• Relief displacement is inversely proportional to the principal distance.

7. Photogrammetric Instruments and Concepts: Correct Statements

Select the correct answer(s):

• The comparator is a component of analog restitution instruments.
• Stereo parallax is directly proportional to the height of the terrain.
• Measurement techniques for groups improve the radiometric quality of the scanned image.
• Depth of field will be greater with a longer camera focal length.

8. Photogrammetric Camera Calibration Methods

Name the different methods of calibration for a photogrammetric camera:

• Laboratory methods
• Field methods
• Stellar methods