This set of Surveying Multiple Choice Questions & Answers (MCQs) focuses on “Flight Planning for Aerial Photography”.
1. Overlapping in the direction of flight can be described as_____________
a) Forward overlap
b) Side lap
c) Backward overlap
d) Adjacent overlap
Explanation: While taking photographs, each strip is placed at a pre-determined distance which might be able to provide side lap between the adjacent strips. Overlapping in the direction of flight can defines as forward lap, as the flight moves forward. The frequency while taking photographs will be under control to avoid overlapping.
2. Which of the following indicates the correct set of overlapping percentage?
Explanation: Overlapping must be done at a desired rate. Excessive overlapping can cause the photograph more complex, with which the time for obtaining output increases. Frequency of the camera must be under control so as to avoid successive overlapping. The percentage of overlapping must be in a range of 55-60 %.
3. Overlapping occurred due to adjacent flight lines can be termed as__________
a) Front lap
b) Forward lap
c) Side lap
d) Straight lap
Explanation: While combining the photographs taken by two adjacent flights, it might lead to side lapping. The entire area in the photograph must be examined stereoscopically. This can be done only when the photographs are taken by adjacent flights.
4. Determine the distance of flight strips if the height lens placed is given as 56m.
Explanation: For calculation of distance of the flight strips, W = 1.22*H is used. On substitution, we get
W = 1.22*56
W = 68.32m.
5. What will be the distance between the flight strips if the value at point B is given as 6m?
Explanation: The calculation of distance between flight strips along with a point can be determined by using the relation, W = 2*B. On substitution, we get
W = 2*6
W = 12m.
6. The formula for determining the distance between flight strips can be given as_________
a) W = 1.22+H
b) W = 1.22-H
c) W = 1.22/H
d) W = 1.22*H
Explanation: Distance between the flight strips can be calculated as W = 1.22*H. Here, H indicates the height of lens placed above the ground. By calculating the distance between the strips it can be useful for determining the complication of points observed.
7. Overlapping increases the amount of work to be done.
Explanation: Overlapping occurs due to the combination of photographs to cover the entire area. It depends upon of the frequency, shutter speed of the camera. The coverage area increases with increase in over lapping and side lapping, which means work to done at field and at office increases.
8. The relation between normal direction of flight and the rectangular area can be given as_________
a) 2W = 2*B
b) W = 2*B
c) 3W = 2*B
d) 4W = 2*B
Explanation: In a maximum rectangular area, the rectangle must have the dimension in the direction of flight which has to be one-half the dimension normal to the direction of flight.
9. Calculate the flying height if the contour interval is given as 6m.
Explanation: The flying height can be determined by using the formula,
Flying height = contour interval * c-factor. The value of c-factor lies in between 500-1500. On substitution, we get
Flying height = 6*500 = 3000m.
10. Unless the area is mapped, W value must be reduced.
Explanation: The determination of distance between the flight strips is related to the area mapped. The area mapped is covered by a certain number of flight paths which in turn reduces the value of W.
11. The value of c-factor lies in between ____________
Explanation: C-factor indicates a number, which is used for calculation of flying height. This factor depends on the conditions of the surroundings which cover the map-compilation operation, having a range 500-1500.
12. Which of the following is not considered while calculating distance between flight strips?
a) Vertical photographs
b) Mitigating crab
c) Eradicating drift of the aircraft
d) Line of sight
Explanation: The calculation of flight strips involves determination of level terrain, vertical photographs, mitigating crab and eradicating drift of the aircraft. All of these must be maintained for a better result.
Sanfoundry Global Education & Learning Series – Surveying.
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