Defination, Objectives, Classification, Comparision of map & Aerial Photograph & Types of Aerial photographs

1. Advance Surveying
Aerial Photogrammetry
Prof. Rajguru R.S.
Civil Engineering Department
(rajgururajeshcivil@sanjivani.org.in)
Sanjivani College of Engineering,
Kopargaon,MH,India

2. Lecture Outline
 Definition
 Objectives
 Classification: quantitative and qualitative
photogrammetry Application
 Comparison of map and aerial photograph
 Vertical, Tilted and Oblique photograph

3.  Definition of Aerial Photogrammetry:
Aerial Photogrammetry is advance technique of
obtaining the information about object or area
without coming into the physical contact with the
object or area under investigation.
Photo=Picture
Grammetry =Measurement
Photogrammetry= Photo-measurement

4.  Objectives:
• To prepare the maps
• To make the reconnaissance survey
• To collect the military intelligence
• To interpret the geology and soil data
• To make survey of remote area
• To make survey of buildings
• To conduct environmental assessment
• To conduct Power line inspection
• To conduct forest survey
• Movie production

5.  Classification:
Sr. No. Terrestrial photogrammetry Aerial photogrammetry
1
2 Photographs are taken by photo
theodolite mounted at stationary
and elevated position.
Cameras fit to an aeroplane that flies
take pictures
3 Terrestrial photogrammetry
comparatively needs much less
investment and technical skill to
carry out.
Aerial photogrammetry requires a
high-end infra support:
4 To map a small piece of land. To map a large piece of land.
5 Maps are compiled from the
photographs
Accessories required for
interpretation & plotting the maps

6.  Comparison of map and aerial photograph:
Sr. No. Map Aerial photogrammetry
1
2 It is an orthogonal Projection. It is a central Projection
3 A map is a geometrically correct. An aerial photograph is a geometrically
incorrect.
4 The scale of the map is uniform The scale of the photograph is not
uniform
5 Enlargement/reduction of the maps
involves redrawing it
Enlargement/reduction does not change
the contents of the photographs
6 Map reading is common and more
familiar to users
Photograph needs a special technique to
read the photo-views
7 Plotting of map is economical Plotting of map is uneconomical
8 Map Prepared by conventional
method
Aerial Photograph preparation is highly
skill job
9 Time consuming method Time saving method

7.  Types of Photographs: Vertical , Tilted & Oblique
Types of aerial photographs on the basis of orientation of
camera axis:
• Vertical photograph: An aerial photograph taken with the camera
axis/optical axis coinciding with the vertical to the ground is known as
vertical photograph.
• Tilted photograph: An aerial photograph in which the camera axis is
unintentionally tilted by small amount (less than 3 °) from
vertical/perpendicular to the ground is known as tilted photograph.

8. • Oblique photograph:
An aerial photograph taken keeping the camera axis intentionally tilted from
the vertical is known as oblique aerial photograph. The amount of tilt ranges
from 30° to 60 °. The advantage of oblique photographs is that they cover
large area and they also provide side view of features.
Oblique photographs are of two types –
Low oblique: Oblique photographs in which horizon is not seen. Tilt is 30°.
High oblique: Oblique photographs in which horizon is seen. Tilt is 30° to 60°.

9. Thank you