geo 420 dr. garver. what is remote sensing what is it used for history
TRANSCRIPT
GEO 420Dr. Garver
What is remote sensing
What is it used for
History
remote sensing (v) the science of deriving information about the earth's land, atmosphere and water areas from images acquired at a distance.
Relies on measurement of electromagnetic energy reflected or emitted from the features of interest.
1950s - term coined by Evelyn Pruitt
Geographer/oceanographer with U.S. Office of Naval
Research (ONR).
Term was devised to take into account the new views
from space obtained by the early meteorological
satellites which were more "remote" from their targets
than the airplanes that up until then provided aerial
photos as the medium for recording images of the
Earth's surface.
Main Entry: syn·op·tic
Function: adjective
Etymology: Greek synoptikos, from
synopsesthai
1 : affording a general view of a whole
2 : manifesting or characterized by
comprehensiveness or breadth of view
3 : relating to or displaying conditions (as of
the atmosphere or weather) as they exist
simultaneously over a broad area
Tornadoes - F-5 - largest and most powerful classification - winds 300 m/h.TGOES-East weather satellite produces images of most of U. S. every 30 min. in vis and IR wavelengths.
Pronunciation: "re-z&-'lü-sh&n”
Function: noun
the process or capability of making
distinguishable the individual parts of
an object, closely adjacent optical
images, or sources of light.
the point in a literary work at which the chief
dramatic complication is worked out.
Unique view of our planet.
Remote sensing allows us to examine, in
unprecedented detail, characteristics of
our atmosphere, oceans, and land areas.
Use sensors to view the spectral and
spatial relations of objects at a distance.
CZCS
The term "photography" is derived from
two Greek words meaning "light" (phos)
and "writing" (graphien).
No one knows when humans first
constructed a device that would record
images by means of light
The First PhotographThe First Photograph
first photograph obtained by Joseph Nicephore Niepce of his French estate courtyard in 1827. Exposure lasted 8 hours.
first photograph obtained by Joseph Nicephore Niepce of his French estate courtyard in 1827. Exposure lasted 8 hours.
Put sheets of silver salts at back of camera obscura, known to blacken with daylight. Called these images “retinas“ .
First known aerial photograph was obtained by Gaspard Felix Tournachon (Nadar) from a tethered balloon 1,700-ft. above Paris, France in 1858.
Took first photographs in 1853 and in 1858 became the first person to take aerial photographs
First known aerial photograph was obtained by Gaspard Felix Tournachon (Nadar) from a tethered balloon 1,700-ft. above Paris, France in 1858.
Took first photographs in 1853 and in 1858 became the first person to take aerial photographs
1850s- balloonists took pictures of ground using newly invented photo-camera.
Oblique photograph obtained from the Hippodrome Balloon using a multiband camera.
Also pioneered the use of artificial lighting in photography, working in the catacombs of Paris.
Oblique photograph obtained from the Hippodrome Balloon using a multiband camera.
Also pioneered the use of artificial lighting in photography, working in the catacombs of Paris.
Served as a prime remote sensor for more than 150
years.
Captures image of targets exterior to it by
concentrating electromagnetic (EM) radiation
(visible light) through a lens onto a recording
medium.
Key advance occurred in 1871 - development of
photographic negative.
Silver halide film remains the prime recording
medium today.
Film displays objects by variations in brightness of
gray levels (black and white) or color tones.
Late 1800s – Early 1900s Pigeon fleet used to carry cameras
Photograph of a castle taken automatically by a camera strapped on a pigeon in flight
Aerial photography - reconnaissance tool in WW I and II
1946 - Remote sensors in space began with photo-camera systems on captured German rockets.
Power and capability of launch vehicles big factor in determining what remote sensors could be placed as part of the payload.
Dawn of the Space Age – R. S. above the atmosphere (both Russian and American).
• 1957 - Soviet Union launched Sputnik I • World's first artificial satellite• Size of a basketball, 183 pounds• Ushered in new political, military, technological, and scientific developments. • Start of the space age and U.S.-U.S.S.R space race.
First ever U.S. satellite in Earth orbit designedto image and monitor weather. TIROS-1, launched April, 1960 soon after NASA came into existence.
Image is considered the official start of remote sensing from satellites.
First cosmonauts/astronauts used
hand-held cameras.
1960’s - Black and white TV-like
images of Earth from
meteorological satellites.
First non-photo sensors were television cameras mounted on unmanned spacecraft to look at
clouds.
TIROS-1
Superimposed on
cloud patterns is a
generalized weather
map; this kind of
data display soon
started to appear in
television news
broadcasts.
1961 - First American in Space?
1970's – matured - repetitive
schedule instruments on
Skylab ( then Space Shuttle)
Landsat - first satellite dedicated to
mapping natural and cultural
resources on land and ocean surfaces.
Set stage for other satellite systems
Demonstrated power & versatility of
multispectral imagery* for observing Earth
Monitors natural & human made features over
time.
Since 1972, six Landsats have been orbited
successfully.
*multispectral scanner-Scanner system that simultaneously acquires
images of the same scene at different wavelengths.
Early Landsat image (Utah 1972)
1978 - radar imaging system main sensor on Seasat.
First satellite designed for remotesensing of oceans with SAR.
Mission - demonstrate feasibility of global satellite monitoring of oceans.
Collect data on sea-surface, winds, SST, wave heights.
1980 - specialized sensors
Coastal Zone Color Scanner (CZCS)
Ocean color = biology
Advanced Very High Resolution
Radiometer (AVHRR)
Vegetation cover, SST
Space shuttle (1982) - JPL's Shuttle
Imaging Radar (SIR-A).
Sea Surface Height
Main Entry: ra·di·om·e·ter
Pronunciation: "rA-dE-'ä-m&-t&r
Function: noun
: an instrument for detecting and
measuring the intensity of radiant
energy;
- ra·di·om·e·try /-m&-trE/ noun
CZCS image of Gulf Stream - April 1982 - warm-core ring.
AVHRR - SST
1980s - Landsat privatized,
widespread commercial use of
remote sensing.
Improved sensor - Landsat-5
Thematic Mapper (TM; 30m
resolution).
Improvement in detail of later Landsats owing to new sensor.
Mosaics - images of entire Earth or continents.
Color view of continental U.S from summer
AVHRR.
Notice regionally variable distribution of
vegetative cover (green).
Variety of sensors on land and sea
satellites
Launched by U.S. govt., private U.S.
industry and other countries.
Most observe in;
Visible
Near IR
Thermal infrared
Some radar
Land observers ‘72 – ‘96
Remote sensing has become major
tool for monitoring
earth/atmosphere system.
BIG BUCKS SPENT on applications
for environmental and natural
resource management.
Huge improvements in;
Computer-based image processing
PC’s can handle large amounts of
data
Makes data accessible to
universities, govt. agencies,
environmental companies, and
individuals.
Satellites ‘95 – ‘05Note # of commercialsatellites.
Spain and NW Africa – Feb. 13, 2001. Dust blowing off Sahara forms question mark over Atlantic Ocean west of Spain.
Commercial Data- OrbimageSeaWiFS sceneNear true color
1999 - reliable stream of image data that has become the standard for commercial high-resolution satellite data products.
IKONOS produces 1-meter black-and-white (panchromatic) and 4-meter multispectral (red, blue, green, near infrared) imagery.
Wide range of high-resolution imagery applications.
Before Sept. 11
IKONOS
After Sept. 11
IKONOS
1m res satellite image of Manhattan on Sept. 12, 2001 by Space Imaging's IKONOS satellite.
Shows an area of white and gray-colored dust and smoke at the location where the 1,350-foot towers of the WTC once stood.
IKONOS
IKONOS
Commercialization of space imagery is
currently a huge deal in the remote sensing
field.
Emergence in 21st Century of private,
commercial satellite operations
Rather than continued dependence on
NASA/NOAA, space agencies in other
countries, and the military to provide useful
imagery.
But remote sensing operations are still in
large part government-driven (U.S. and Intl).
Huge need to monitoring terrestrial
systems.
observe, quantify, map changing land use,
protect natural resources,
track interactions within the biosphere,
atmosphere, hydrosphere, and geosphere