Photogrammetry & Remote Sensing

About the Science & Technology of Photogrammetry

The science of photogrammetry started early in the 20th century with simple mechanical devices to orient two photographs relative to each other, and the resulting model relative to the ground. The technology progressed to the use of sophisticated optical-mechanical systems, but still using essentially the same concepts. The late 60's / early 70's saw the introduction of computers using the concept of analytical photogrammetry in order to control precision instruments to orient and measure the stereo models. This results in very high precision due to precise numerical calculations as opposed to mechanical approximations. This method improved speed, efficiency, and accuracy and allowed transition from paper-based maps to digital maps.


Wild Autograph A7
Wild Autograph A8
Kelsh Plotter
Kern PG-3

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The early years of Photogrammetry produced the Autograph A2 in 1925 and many types of mapping equipment evolved from there.


Point Transfer Device
Stereo Plotter
Computer Workstation
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The early 1990s saw the introduction of fully computerized photogrammetry. This technology is based on scanned photographs displayed on a computer screen with the same mathematical concepts and precision as the analytical stereo plotter. This method displays two images on a single screen with special liquid crystal shutters that allow the left and right eye to see the left and right images resulting in 3D computer display. Computerized Photogrammetry allows us to view the ground with ALL the map data superimposed on the stereo model in STEREO and in COLOR.


Flat Screen Monitors 3DTL Workstation 3D Terrestrial Scan Image
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Computerized Photogrammetry is now the leading technology for mapping. WSDOT photogrammetry uses 100% of this superior technology. See more about our latest mapping technology with 3DTL.


Web Contact:
Keith Anderson

Updated 9/28/15