NCERT Solutions for Class 11 Geography Chapter 11 - Introduction to Aerial Photographs

Question 1:

In which of the following aerial photographs the horizon appears?

  1. Vertical
  2. Near-vertical
  3. Low-oblique
  4. High-oblique
Answer:

(d). High-oblique

Question 2:

In which of the following aerial photographs the Nadir and the principle points coincide?

  1. Vertical
  2. Near-vertical
  3. Low-oblique
  4. High-oblique
Answer:

(a). Vertical

Question 3:

Which type of the following projections is used in aerial photographs?

  1. Parallel
  2. Orthogonal
  3. Central
  4. None of the above
Answer:

(c). Central

Question 4:

State any three advantages that an aerial photograph offers offer over ground based observations.

Answer:

The advantages are:
1. Improved vantage point
2. Time freezing ability
3. Broaded sensitivity
4. Three dimentional perspective

Question 5:

How is an aerial photograph taken?

Answer:

The aerial photograph is taken from an aircraft or a helicapter using a precision camera.

Question 6:

Present a concise account of aerial photography in India?

Answer:

Aerial photographs were started in 1920 when large scale aerial photograph of Agra City was taken. Air survey party of survey of India took up erial survey at Irawadi Delta forests which are completed in 1923- 24.
Today aerial photographs in India are carried out for the entire region unair the over all super vision of the Directorate of Air Survey, New Delhi. Three flying agencies are Indian Air Force, Air Survey Company, Kolkata and National Remote Sensing Agency, Hyderabad have been afficially authorised to take aerial photographs.

Question 7:

What are the two major uses of an aerial photograph? Elaborate.

Answer:

The uses of an aerial photographs are: (1) Photogrammetry: The technique of obtaining information from photographs is called photogrammetry of making reliable measurements from aerial photographs.
(2) Image Interpretation: It is an art of identifying images of objects and judging their relative significance.

Question 8:

What are the different methods of scale determination?

Answer:

There are three different methods of scale determination these are:
(1) By establishing relationship between photo distance and ground distance: In this method if additional information like ground distance of two idenfifiable points in an aerial photograph is available it is simple to work out the scale of vertical photograph.
(2) By establishing relationship between photo distance and map.
(3) By establishing relationship between focal length and flying height of the Aircraft.