2. PHOTOGRAMMETRY:
Photogrammetry is a surveying and mapping technique which
can be used in various applications. There are many uses of
Photogrammetry in the surveying industry such as topographic
mapping, site planning, earthwork volumes, production of
digital elevation models (DEM) and orth photography maps.
Photogrammetry describes from three words:
‘photo’ – light
‘gram’ – drawing
‘metry’ – measurement
The output of photogrammetry is typically a map, drawing,
measurement, or a 3D model of some real-world object or scene.
3. AERIAL PHOGRAMMETRY
AERIAL PHOTOGRAPH:
Photographs taken from a platform, usually an
airplane , flying above the earth’s surface.
Can be taken from space but usually taken from within
the atmosphere.
TYPES OF AIR PHOTOS:
Vertical air photos
• Vertical or nearly vertical angle to the local ground surface
Oblique air photos
• Tilted away from vertical
High oblique Low oblique
5. Photographs of terrain in an area are taken by a precision
photogrammetric camera mounted in an aircraft flying over
an area
AERIAL PHOGRAMMETRY
AERIAL PHOTOGRAMMETRY
Technique of obtaining reliable measurement of objects
from their photographic images.
• Height of object
• Areas
• Lengths
• Density
6. Geological investigation
Soil survey
Urban and Regional Development
Transportation system
Shore erosion
AERIAL PHOGRAMMETRY
USES
7. AERIAL PHOGRAMMETRY
ADVANTAGES:
The foremost advantage of photogrammetry is the ease and speedat
which the data can be collected.
The photogrammetric techniques yield results that are highly
accurate making it very reliable to use for mapping or other purposes.
It offers a wide or broad view of the mapped area by utilizing both
topographic and cultural features of the land surface.
DISADVANTAGES:
The major disadvantage is that the photogrammetric survey is not
possible in the absence of light.
The accuracy of the measurements depends highly on the flight
height.
The digital aspect of the photogrammetry surveys makes it susceptible
to hacks and loss of data due to viruses.
