Surveying Multiple Choice Questions on “Aerial Photogrammetry”.
1. The lens used in aerial photogrammetry is having a maximum coverage capacity of _________ (in angles)
a) 930
b) 630
c) 530
d) 980
Answer: a
Clarification: In general, the lens used in aerial photogrammetry having a minimum coverage area of 630 and a maximum coverage area of 930. The usage of the coverage angle depends upon the type f land being surveyed and the accuracy needed in output.
2. Which of the following is not a type of shutter used in aerial photogrammetry?
a) Between-the-lens shutter
b) Louvre shutter
c) Ideal shutter
d) Focal plane shutter
Answer: c
Clarification: Shutter plays a prominent role in the process of aerial photogrammetry. The speed of shutter must be in such a way that it should function at a speed of 1/100 to 1/1000 second. It is classified as between the lens type, focal plane type, Louvre type.
3. For placing focal plane, which is used as a reference?
a) Focal length
b) Horizon
c) Azimuth
d) Collimation marks
Answer: d
Clarification: Collimation marks can be used as a reference while placing the focal plane. It may place the focal plane at a near distance from nodal plane from which the best possible image can be obtained.
4. Focal plane varies while aerial photogrammetry is carried out.
a) True
b) False
Answer: b
Clarification: In the process of aerial photogrammetry, the air-craft is placed at a considerable height so that it can cover a huge area while taking photographs. But the focal plane of the aerial camera is fixed at one location, rather than varying.
5. Which among the following surveying methods is meant to be having high precision?
a) Aerial photogrammetry
b) Terrestrial photogrammetry
c) Theodolite surveying
d) Traverse surveying
Answer: a
Clarification: Though terrestrial photogrammetry is having accuracy in the obtained values, aerial photogrammetry is capable of producing precise output when compared to the remaining methods. This accuracy makes it different from the remaining methods and is recommended when high quality works are conducted.
6. Vertical photograph coincides with the__________
a) Direction of line of sight
b) Direction of lens
c) Direction of aperture
d) Direction of gravity
Answer: d
Clarification: The aerial photograph consists of a vertical photograph which is made of the camera axis which is made to coincide with the direction of gravity. Optical axis must be first made straight in order to continue further.
7. How much inclination must be provided in a tilted photograph?
a) 13˚
b) 20˚
c) 3˚
d) 34˚
Answer: c
Clarification: In general, a tilted photograph consists of inclination up to 3˚, which makes it to have an individual tilted scale. It might help in determining the objects which are inclined in the photograph.
8. If the apparent horizon is shown in a photograph, it is low oblique.
a) True
b) False
Answer: b
Clarification: Oblique photograph is used in case of aerial photography, with an intention that the camera axis lies in between horizontal and vertical. High oblique is obtained in case of possessing apparent horizon otherwise it isn’t shown.
9. Perspective projection is produced from__________
a) Straight lines radiating a common point
b) Straight lines radiating different points
c) Parallel lines radiating a common point
d) Perpendicular lines radiating a common point
Answer: a
Clarification: The introduction of perspective projection is done by the straight lines radiating a common point and passing through point on the spherical surface. Aerial photogrammetry uses this phenomenon.
10. Flying height refers to_________
a) Upper portion of the exposure station
b) Bottom of the exposure station
c) Depression of the exposure station
d) Elevation of the exposure station
Answer: d
Clarification: Flying height indicates the elevation of the exposure station above the sea level. Any datum selected can act as a reference so that the flying height can be considered from them.