This is an evolving document, clearly in its infancy. If you would
like a term added or explained, please fill out the form below or drop
us a line: email@example.com.
Links to other sources
More extensive glossary, unsorted and yet to
be integrated with this list.
Data gathering by a sensor that is not in the immediate vicinity of the
object sensed. RS usually refers to photography by satellites or
aircraft, but technically includes video photography, human vision, and
non-optical sensing such as household motion detection.
Aerial Photograph, oblique:
A photograph taken with the camera axis directed between the horizontal
and the vertical
A pair of photos with overlap in area and are suitable for stereoscopic
Advanced Very High Resolution Radiometer is a multispectral imaging system
carried by the polar-orbiting, crosstrack, multispectral scanner on the
TIROS-NOAA series of meteorological satellites acquiring five spectral
bands of data (0.55 to 12.50 µm) with a ground resolution 1.1 x 1.1
Airborne Visible Infrared Imaging Spectrometer. Imaging from high-altitude
(U2, about 15 km altitude, 20m resolution) and low-altitude (Twin Otter,
3 km altitude, 4m resolution) aircraft.
A commercial imaging satellite launched by Space
Imaging in late 1999. Output: 1m panchromatic, 4m 4-band
The currently functioning satellite is Ikonos-2. Its predecessor
suffered a launch failure.
Indian Remote Sensing satellite. Not to be confused with the Internal
Revenue Service, the US tax collection agency.
Sponsored by the U.S. government, the first Landsat satellite was launched
in 1972 with a resolution of approximately 80m. The most recent, Landsat
7, a multispectral sensor, was launched on April 15, 1999 and includes
the Enhanced Thematic Mapper Plus (ETM+) with a resolution of approximately
A pair of commercial imaging satellites, Quickbird-1 and Quickbird-2, to
be launched by EarthWatch Inc (Colorado) in late 2000, with output of 1m
4m 4-band multispectral, equivalent to AVIRIS. Their predecessor,
Earlybird, suffered a communications failure shortly after launch in December
Synthetic Aperture Radar data provided by the Canadian company, Radarsat
International, established in 1989. Specifications include: 7 beam
modes with image sizes ranging from 50 x 50 km to 500 x 500 km and resolutions
ranging from 8m to 100m
Refers to data provided by SPOT Image Corporation , a subsidiary of SPOT
Image S.A. The company was established in 1982 and has since launched 4
satellites and provides a variety of data and products from these satellites.
Resolution is 20m for multispectral bands and 10m for the panchromatic
Shuttle Radar Topography Mission is a NASA/NIMA sponsored mission designed
to use C-band and X-band interferometric synthetic aperture radars (IFSARs)
that acquired topographic data over approximately 80% of Earth's land mass
during an 11-day Shuttle mission launched February 11, 2000.
Intermap Technologies supplies Global Terrain products including Orthorectified
images (ORIs) and Digital Elevation Models (DEMs). Their STAR-3i sensor
is an Interferometric Synthetic Aperture Radar (INSAR) mounted in a Learjet
36 aircraft that acquires a 10km wide swath of 2.5m resolution radar data
More extensive glossary, unsorted and yet to be
integrated with this list.
Light Detection and Ranging, the laser equivalent of radar. A laser
swath is emitted and the return beam is sensed, usually by a low-altitude
aircraft. This enables accurate distance ranging, and the consequent
ability to produce ~20cm contour maps and 3-D oblique images. The
technique is sometimes called Airborne Laser Terrain Mapping or ALTM.
Modern sensors are capable of capturing separate reflectances over a couple
of hundred different wavelengths, so that each pixel is associated with
a curve of intensity vs wavelength. Because of absorption by atmospheric
water and dust, not all portions of the spectrum produce good signals.
Sensing in usually 4 distinct wavelength bands (equivalent to colors, not
all of which are visible to the human eye). Because the data handling
capacity of the sensor is spread over these different wavelengths, this
usually translates to lower resolution than
Also see hyperspectral.
Sensing in a single wide band, resulting in high-resolution monochromatic
image. Contrast against multispectral and hyperspectral.
Synthetic Aperture Radar. In radar terms, aperture is the band width
over which the antenna gathers data. In general a long radar antenna
gathers information over more wavelengths, but is difficult to send into
space. SAR uses the motion of the space platform to simulate antenna
length. An object is imaged while the craft travels about 4 km through
space — with a little clever processing of the signals, this displacement
of the antenna relative to the object is used to simulate a 4 km long antenna.
Radar Topography Mission is a celebrated example of the application
of SAR. A good introductory resource on SAR is the Alaska SAR facility,
NASA Headquarters, Washington, DC
Goddard Space Flight Center,
Jet Propulsion Laboratory, Pasadena,
Johnson Space Center, Houston,
Kennedy Space Center, FL
Marshall Space Flight Center,
Moffett Federal Airfield,
Mountain View, CA
Stennis Space Center, MS
Brunel University: List
of RS satellites and sensors
Additional glossaries on transportation
Jeff Hemphill, Remote Sensing Research Unit, UCSB, web site for the class,
ERS-1 Calibration and Validation, ESA bulletin no 65, February 1991, by
E. Attema and R. Francis.
Manual of Remote Sensing, Leonard Bowden, American Society Photogrammetry
and Remote Sensing, Falls Church VA, copyright 1975
Please use this to suggest a term (with or without a description) that
we've missed. Where relevant, please include URLs and references.