Engineering Metrology Multiple Choice Questions on “Photogrammetry”.
1. How many location photographs are required (at least) for photogrammetry?
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: In photogrammetry photograph are taken from at least two different locations so that “lines of sight” can be developed from each camera to points on the object. These lines of sight are intersected mathematically to produce the 3-D coordinates of the points of interest.
2. What does the inner orientation of camera define in photogrammetry imaging process?
a) Geometric parameters of the imaging process
b) Location of object points in space
c) View direction
d) Finding fixed points
Answer: a
Clarification: The coordinates of image define the locations of the object points on the film. The exterior orientation of a camera defines location of points in space and direction of view. The inner orientation of camera defines the geometric parameters of the imaging process.
3. What does close range photogrammetry called in computer vision community?
a) Topographic modeling
b) Image-based modeling
c) Aerial photogrammetry
d) Engineering photogrammetry
Answer: b
Clarification: In Terrestrial photogrammetry also known as close-range Photogrammetry, the camera is located on the ground, pole mounted and handheld. This type of photogrammetry is sometimes called Image-Based Modeling in the computer vision community.
4. What is the fundamental principle of photogrammetry?
a) Interference
b) Resection principle
c) Triangulation
d) Intersection principle
Answer: c
Clarification: Photogrammetry is a 3-D coordinate measuring technique that uses photographs as the fundamental medium for metrology. The fundamental principle used by this technique is triangulation or Aerial Triangulation.
5. What is the type of photograph if the tilt of the axis of the camera from the plumb line is 2 degrees?
a) Oblique photograph
b) Horizontal photograph
c) Tilted photograph
d) Vertical photograph
Answer: d
Clarification: If the tilt of the axis of a camera from the plumb line is less than 3 degree then the photograph is vertical photograph but if the tilt of camera axis is more than 3 degree then it is called as tilted photograph.
6. What is the type of photograph on which the apparent horizon doesn’t appear?
a) Low oblique
b) High oblique
c) Tilted
d) All type of oblique photographs
Answer: a
Clarification: Oblique photographs are of two types : High oblique photograph and low oblique photograph. High oblique photograph is an oblique photograph in which the apparent horizon appears while low oblique photograph: is one on which the apparent horizon doesn’t appear.
7. Which is not correct about interpretative photogrammetry?
a) It form basis for remote sensing
b) Involves study of photographic images
c) Involves recognition and identification of objects and judgement of their significance
d) Also involves the use of collected data after analysis
Answer: d
Clarification: Photo interpretation or interpretative photogrammetry involves the study of photographic images but remote sensing involves not only the photograph analysis but also the use of data collected from remote sensing instruments.
8. Which of the following option is true for given statements about photogrammetry?
Statement 1: Both aerial and terrestrial photogrammetry used in Urban planning.
Statement 2: Terrestrial photogrammetry is more suitable for movement related issues.
a) T, T
b) F, F
c) F, T
d) T, F
Answer: a
Clarification: Urban planning takes advantage of terrestrial and aerial methods. Planners and designers collaborate on the best perspective for a specific project using aerial photogrammetry and terrestrial photogrammetry helps to see the interrelation between urban constructions, security issues etc.
9. Which photogrammetry method has topographical mapping as a common application?
a) Interpretative Photogrammetry
b) Metric photogrammetry
c) Aerial Photogrammetry
d) Space Photogrammetry
Answer: b
Clarification: Metric photogrammetry consists of making precise measurements on photographs to determine relative point locations. Common applications of Metric Photogrammetry are topographical mapping and plan metric mapping.
10. Which instrument lets an operator see two photos at once?
a) Goniometer
b) Collimator
c) Theodolite
d) Stereo plotter
Answer: d
Clarification: Stereoscopic plotting instruments or stereoplotters or plotters are the instruments designed to provide accurate solutions for point positions of objects from their corresponding positions of images on overlapping pairs of a photo.