SURE 340 - Photogrammetry

Introduction to Photogrammetry 1

O C O OINTRODUCTION TO PHOTOGRAMMETRY

Center for Photogrammetric TrainingFerris State University

RCB

DEFINITIONArt, science, and technology of obtaining gy greliable information about physical objects and the environment through processes of recording, measuring, and interpreting photographic images and patterns of recorded radiant electromagnetic energyrecorded radiant electromagnetic energy and other phenomenon

SURE 340 - Photogrammetry

Introduction to Photogrammetry 2

PhotogrammetryIdeal technology when measuring objects such as

I l hIrregular shapesMoving shapesInflated shapesObjects that are too

• Hot or cold• Soft• Delicate• Inaccessible• Toxic• Radioactive to touch

METRIC PHOTOGRAMMETRY

Making precise measurements from photos g p pand other sources to determine relative locationThree basic applications

AerialT i lTerrestrialExtra-Terrestrial

SURE 340 - Photogrammetry

Introduction to Photogrammetry 3

INTERPRETATIVE PHOTOGRAMMETRY

Recognizing and identifying objects and g g y g jjudging their significance through careful and systematic analysisTwo main applications

Photographic interpretationR iRemote sensing

TERRESTRIAL PHOTOGRAMMETRY

Taken with ground-based camerasPosition and orientation often measured

SURE 340 - Photogrammetry

Introduction to Photogrammetry 4

BC4 BALLISTIC PLATE CAMERA

TERRESTRIAL PHOTOGRAPHIC STEREOPAIR

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AERIAL PHOTOGRAPHYVertical – camera axis as nearly vertical as ypossibleOblique – camera axis intentionally tilted

Low obliqueHigh oblique

VERTICAL PHOTO

SURE 340 - Photogrammetry

Introduction to Photogrammetry 6

HIGH OBLIQUE

LOW OBLIQUE

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Introduction to Photogrammetry 7

EXTRATERRESETRIAL PHOTOGRAPHYExtraterrestrial – pictures taken from space-based

camerasApollo-Saturn 4

TAKING VERTICAL AERIAL PHOTOGRAPHS

Photos taken in parallel flight stripsp g pEach successive photograph overlap previous photo

Called end lap or overlap – usually 60%Area of common coverage called stereoscopic

loverlap areaOverlapping pair of photos called a stereopair

SURE 340 - Photogrammetry

Introduction to Photogrammetry 8

TAKING VERTICAL AERIAL PHOTOGRAPHS

STEREOPAIR

SURE 340 - Photogrammetry

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TAKING VERTICAL AERIAL PHOTOGRAPHS

Position of camera at each exposure called pexposure stationFlying height – altitude of cameraAdjacent flight strips overlap

Called side lapBlock of photos – photos of 2 or more side lapping strips

APPLICATIONS OF PHOTOGRAMMETRY

Topographic mapping AstronomyOrthophotography

Equivalent to planimetric map

Digital elevation model (DEM)

Mapping (tax maps, soil maps, etc.)ArchitectureArchaeologyTraffic accident i ti tiNumerical

representation of topography

investigationMedicine/dentistryGIS

etc…