close range photogrammetry avinash
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ByyAvinash Kumar SinghM.Tech Geomatics13520004
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Photogrammetryclassification based on photography
Aerial TerrestrialPh h k i h l d h fPhotographs taken with a camera located on the surface of the earth.
Close Range PhotogrammetryTerrestrial photograph having object distances of up to about 300 meter.
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Close Range Photogrammetry in hArchitecture
In 1885 Meydenbauer began theIn 1885, Meydenbauer began the photogrammetric monument archive in GermanyGermanyNot only recording of buildings and monumentsmonumentsReconstruction after damageDetermination of deformation and changesMeasurement related to architectural work
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Basically there are three groups in lAnalogue Instruments
1 Normal Case Plotter: Which are often a part of a Close Range1. Normal Case Plotter: Which are often a part of a Close Range
Photogrammetric system.2 Universal Plotter: h h h f l l f l d h2. Universal Plotter: Which have fairly large range of tilt, depth,
principal distance and Base setting and which are used for both aerial and
terrestrial photographs.p g p
3. Mapping or Topographic Plotter: Which are designed for aerial mapping, accept vertical or nearly vertical photographs and can
sometimes be used for close range photogrammetry.
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Types of Cameras usedTypes of Cameras used
Metric CameraMetric CameraNon Metric Camerah i l l if i h iThe simplest way to classify is the existence or non existence of Fiducial Marks.
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Stereometric Camera( Camera Plotter System)Stereometric Camera( Camera Plotter System)
• 1920 to 1960• Applied to Architecture• Archaeology• Civil Engineering• Mining Engineering• Surveying of Traffic Accidents• Limitations because of restricted choice of cameraPl tti j ti l t fi d l t i• Plotting on projection planes at fixed angle to image plane limits the direction of photography in field
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AdvantagesAdvantages
Object not touched during measurement such as measurement of water waves and currents
Data capture or acquisition is rapidp q p Photographs store semantic and metric data with very high
density Photographs are documents related to time and it can be used Photographs are documents related to time and it can be used
as legal evidence Not only rigid and fixed objects but also deformation and
movement can be measuredmovement can be measured Time dependant parameters such as velocity, acceleration and
frequency can be determined
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AdvantagesAdvantages
Evaluation, repetition and amendment are always possible Photography and evaluation are flexible and can easily be
optimised to the project requirement such as Accuracyoptimised to the project requirement such as Accuracy Invisible part of spectrum can be used for creating images Complicated shapes and movements are easily measured C hi h f th ti t ti l i t t f Cameras which freeze the action at a particular instant of
time make possible measurement of dynamic occurrences such as deflection of beams under impact loads
S i f Gl i (d t i i h i i d Surveying of Glaciers (determining changes in size and velocity of Glacier) thus 4th dimension of time was included in the analysis of measurement.
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DrawbacksDrawbacks
The result of measurement is not is not immediately at hand, because time is needed for photographic processing and for evaluation
Except for the simplest problems the need forExcept for the simplest problems, the need for specialised and expensive equipment makes the method expensive
Errors during photography and development of film can ruin the whole measuring project
I b ibl h h h bj It must be possible to photograph the objectSpecialised instrumentation and personnel are not always availablenot always available
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