Difference between Image and Photograph

Advance surveying
(CE-105)

Lecturer: Kamruzzan Asif (B.Sc-AUST                                    Date: 14 September, 2018

Email: arifzamance@gmail.com, Cell: 01521218623                              Time: 09:00 AM

Photographic surveying

Difference between Photographs and Images

Sl. No.	Photographs	Sl. No.	Images
1	A scene which is recorded on film	1	A scene which is detected electronically
2	Chemical reaction on light sensitive film	2
3	Simple, Cheap and well known	3	Coslty, expensive sensor
4	Only sense in the wave length of  0.3-0.9 µm	4	It sense in many wave length

Terrestrial Photographs:

          a) Photographs are taken from a fixed position

          b) Photographs are taken with the help of Photo theodolite

          c) Based on the principles "if the direction of same objects from the two position are known,

           then the position can be located from the intersection of two rays."

Aerial Photogrammetry: (2 km <d<10 km

        a) Photos are taken from air with the help of air vehicle

         b) Camera is mounted on the air vehicle

         c) Used mainly in extracting of information from ground

         d) Photographs are taken with the camera vertical axis

         e) Best and easy mapping procedure

Note: 

     Exposure station→ Position of camera

     Flying height→ Altitude of camera

     Side overlap → Adjustment flight strip overlap

     Block of photos → Two or more

Ex:1: 

MACON

Real distance, D= d/s

             d= Photographic distance/map distance

             s= Scale

Ex:2: 

Math

 so A = AB

       =((8.65*100)/(1/20000))x((5.13*100)/(1/20000))

       = 17300000 x 10260000

       = 1.77498x10^14 sqm  Ans: