A Zeiss
P3 Planicomp
Landsat
multispectral image
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Photogrammetry
and Remote Sensing
Photogrammetry
Photogrammetry
is the technique of acquiring measurements from photographic images, generally
stereoscopic.
The term photogrammetry was first used by the Prussian architect Albrecht
Meydenbauer in 1867 who produced some of the earliest topographic plans and
elevation drawings.
The use of photogrammetry in topographic mapping is well established
but in recent years the technique has been widely applied in the fields of
architecture, industry, engineering, forensic, underwater, medicine, geology
and many others for the production of precise 3D survey data.
Data acquired by photogrammetric methods is an integral part of the
data input to both geographical information systems (GIS) and computer aided
design (CAD). Indeed it has a role in any area where accurate spatial data
is required.
Remote
Sensing
Remote
Sensing is a closely aligned technology to photogrammetry in that it also
collects information from imagery. The term is derived from the fact that
information about objects and features is collected without coming into contact
with them.
Where remote sensing differs from photogrammetry is in the type of
information collected, which tends to be based on differences in colour, so
land use and land cover is a primary output of remote sensing processing.
Remote
sensing was originally developed to exploit the large number of colour bands
in satellite imagery to create 2D data primarily for GIS. Nowadays remote
sensing tools are used with all types of imagery to assist in 2D data collection
and derivation such as slope. Software tools today tend to embrace a much
wider range of image technologies such as image mosaicing, 3D visualisation,
GIS, radar as well as softcopy photogrammetry.