ENVIRONMENT SCIENCE AND TECHNOLOGY

1. BANARAS HINDU UNIVERSITY
RAJIV GANDHI SOUTH CAMPUS
BARKACHHA MIRZAPUR
FACULTY-INSTITUTE OF ENVIRONMENT AND SUSTAINABLE
DEVELOPMENT (IESD
TOPIC-ASSIGNMENT ON”PHOTOGRAMMETRY”

3. PHOTOGRAMMETRY
 BASIC DEFINITION
PHOTOGRAMMETRY IS THE SCIENCE AND ART OF DETERMINING THE
SIZE AND SHAPE OF OBJECTS BY MEANS OF ANALYSING IMAGES
RECORDED ON FILM OR ELECTRONOC MEDIA.
 PHOTOGRAMMETRY HAS BEEN DEFINED BY THE
“AMERICAN SOCIETY FOR PHOTOGRAMMETRY AND
REMOTE SENSING”(ASPRS) AS THE ART SCIENCE AND
TECHNOLOGY OF OBTAINING RELIABLE INFORMATION
ABOUT PHYSICAL OBJECTS AND THE ENVIRONMENT
THROUGH PROCESSES OF RECORDING,MEASURING AND
INTERPRETING PHOTOGRAPHIC IMAGES AND PATTERNS
OF RECORDED RADIANT EM ENERGY AND OTHER
PHENOMENA.

4. TYPES OF PHOTOGRAMMETRY
(BASED ON CAMERA LOCATION )
 AERIAL PHOTOGRAMMETRY:-
THE CAMERA IS MOUNTED IN AN AIRCRAFT AND IS USUALLY POINTED VERTICALLY
TOWARDS THE GROUND .MULTIPLE OVERLAPPING PHOTOS OF THE GROUND ARE
TAKEN AS THE AIRCRAFT FLIES ALONG A FLIGHT LINE.
(DIGITAL ELEVATION MODELLING)
 CLOSE RANGE PHOTOGRAMMETRY:-
HERE THE CAMERA IS CLOSE TO THE SUBJECT AND IS TYPICALLY HAND
HELD OR ON A TRIPOD.HERE THE OUTPUT IS NOT TOPOGRAPHIC MAPS
BUT INSTEAD DRAWINGS ,3DMODELS MEASUREMENTS AND POINT
CLOUDS.
(IMAGE BASED MODELLING)

5. PHOTOGRAMMETRY
(ON THE BASIS OF TECHNIQUES)
ANALOG PHOTOGRAMMETRY:-
IT IS PERFORMED VISUALLY BY HUMANS AND IS USED WHEN THE
DATA ARE IN A HARD COPY FORMAT SUCH AS A 9 X 9 IN AERIAL
PHOTOGRAPHIC PRINT OR POSITIVE TRANSPARENCY.
DIGITAL PHOTOGRAMMETRY:-
IT IS PERFORMED WITH THE HELP OF COMPUTER USING DIGITIZED
AERIAL PHOTOGRAPHY.

6. PHOTOGRAMMETRY
(ON YHE BASIS OF DIRECTION OF CAMERA AXIS)
VERTICAL PHOTOGRAPH->
IT IS OBTAINED WHEN THE CAMERA ‘S OPTICAL
AXIS IS WITHIN 3 DEGREE OF BEING VERTICAL
TO THE EARTH’S AXIS.
LOW OBLIQUE PHOTOGRAPH->
OBTAINED WHEN THE CAMERA’S OPTICAL AXIS
DEVIATES MORE
THAN 3 DEGREE FROM VERTICAL AXIS.& HORIZON IS
NOT VISIBLE
HIGH OBLIQUE PHOTOGRAPH->
DEVIATES MUCH MORE (AROUND 60 DEGREE)
AND HERE HORIZON IS VISIBLE

7. PHOTOGRAMMETRY
(ON THE BASIS OF ANGLE)
 NARROW ANGLE=>40 DEGREE FIELD OF VIEW
 NORMAL ANGLE=>70 DEGREE FIELD OF VIEW
 WIDE ANGLE=>90 DEGREE FIELD OF VIEW
 SUPER WIDE ANGLE=>110 DEGREE FIELD OF VIEW

8. PHOTOGRAMMETRY
(ON THE BASIS OF MULTIPLE CAMERA
PHOTOGRAPH)
 CONVERGENT PHOTOGRAPH :
THIS ARE DONE WITH A SINGLE TWIN
LENS WIDE ANGLE CAMERA OR WITH TWO
SINGLE LENS WIDE ANGLE CAMERA
COUPLED RIGIDLY IN YHE SAME MOUNT.
 TRIMETROGEN PHOTOGRAPH :
THIS IS AN ASSEMBLAGE OF 3 PHOTOGRAPHS
TAKEN AT A SAME TIME,1 VERTICAL AND 2
HIGH OBLIQUES IN A DIRECTION AT RIGHT
ANGLE TO THE LINE OF FLIGHT.

9. INFORMATION RECORDED ON AERIAL
PHOTOGRAPHY
o GENERALLY 7 INFORMATION ARE RECORDED IN AERIAL
PHOTOGRAPHY.THESE ARE ::-
• FIDUCIAL MARKS(ARE MARKS ON THE EDGES OF THE CAMERA
FIELD.THEY DEFINE THE CAMERA COORDINATE SYSTEM BY MEANS OF
THE COORDINATE VALUES FOUND ON CAMERA CALIBRATION
CERTIFICATE)
• ALTIMETER(AN INSTRUMENT TO MEASURE THE ALTITUDE OF AN
OBJECT ABOVE A FIXED LEVEL)
• CLOCK(DATE & TIME)
• BUBBLE LEVEL(INDICATE WHETHER THE SURFACE IS HORIZONTAL OR
VERTICAL,ALSO INDICATE TILTNESS)
• FOCAL LENGTH OF LENSE
• CAMERA NUMBER
• NEGATIVE NUMBER

10. GEOMETRY OF AERIAL PHOTOGRAPHY
GENERALLY THREE PROJECTIONS ARE THERE:
 PARALLEL PROJECTION:-
PARALLEL PROJECTIONS HAVE LINES OF
PROJECTION THAT ARE PARALLEL BOTH IN
REALITY AND IN THE PROJECTION PLANE.
 ORTHOGONAL PROJECTION:-
THE TWO DIMENSIONAL GRAPHIC REPRESENTATION
OF AN OBJECT FORMED BY THE PERPENDICULAR
INTERSECTION OF LINES DRAWN FROM POINTS ON TO
THE OBJECT TO A PLANE OF PROJECTION.
 CENTRAL PROJECTION:-
THE PROJECTION FROM A POINT ONTO A
PLANE IS CALLED CENTRAL PROJECTION.

11. TILT IN AERIAL PHOTOGRAPHY
 TILT:-
TILT IS AN ANGLE BETWEEN THE OPTICAL AXIS OF THE
CAMERA AND THE PLUMB LINE OR IT IS ALSO THE
ANGLE BETWEEN THE GROUND PLANE AND THE PHOTO
PLANE.

12. GEOMETRY OF TILTED AERIAL
PHOTOGRAPH

13. TYPES OF TILT
TYPES OF TILT:-
 X-AXIS TILT-> THE TILT ABOUT
THE Y AXIS i .e IN THE
DIRECTION OF
‘X’ IS CALLED LONGITUDINAL
TILT OR ‘FORE & AFT TILT’
 Y-AXIS TILT-> THE TILT ABOUT
THE X AXIS i. e IN THE
DIRECTION OF
‘Y’AXIS IS CALLED Y TILT OR
LATTERAL TILT OR SIMPLE TILT.
REASONS FOR TILT:-
 Atmospheric condition
 Human error
 Imperfection in camera
mounting

14. GEOMETRY OF UNTILTED AERIAL
PHOTOGRAPH

15. OVERLAPPING IN AERIAL
PHOTOGRAPH
 OVERLAP:
OVERLAP INCLUDES THE AMOUNT OF PHOTOGRAPH IN WHICH
ONE PHOTOGRAPH INCLUDES SAME AREA COVERED BY ANOTHER
AND IS CUSTOMARILY EXPRESSED AS A PERCENTAGE.
FORWARD OVERLAP AND SIDE OVERLAP:

16. OVERLAP

17. SCALE MEASUREMENT IN
PHOTOGRAMMETRY
 VERBAL SCALE
S= ab /AB
S=distance between two objects on
photo/distance between two objects on ground
ab =0.113in
AB=56.1ft(0.113/56.1)
Therefore,1 inch=496.46ft
 REPRESENTATIVE SCALE
S=O.113in/56.1ft
S=O.113in/(56.1)*12in
S=1/5957.52
THUS, RF=1:5957

18. SCALE MEASUREMENT BY FOCAL LENGTH OF LENSE AND
ALTITUDE ABOVE GROUND LEVEL
S=f/H
IF , f=12 in
H=60,000ft
VERBAL
SCALE(S)=12/60,000
V.SCALE=>1 in=5000ft
We know,12in=1ft
REPRESENTATIVE
FRACTION
=>1:60,000

19. o S min=f/(H-h min)
o S avg =f/(H-h avg )
o S max=f/(H-h max)
SCALE MEASUREMENT IN VARIABLE TERRAIN

20. RELATION OF PHOTO TO GROUND THROUGH MAP
• R.F OF PHOTO = PHOTO DISTANCE(P)/GROUND DISTANCE(G)
R.F OF MAP MAP DISTANCE(M)/GROUND DISTANCE(G)
R.F OF PHOTO = (P/M) X R.F OF MAP

21. CONCLUSION
• Close-range photogrammetry is being used more
and more as a technique for measuring and
modelling objects. It is relatively quick and easy to
set up, requiring, in its simplest form, simply a digital
camera and a compatible software product. In this
project there has been an introduction to close-range
photogrammetry and some of its applications,
leading to an investigation into how the accuracy of
object coordinates can be optimised through the
network design of camera stations, with a particular
focus on the elements of a camera network which
strengthen or weaken it.