RADARSAT-1
Encyclopedia
Radarsat-1 is Canada
's first commercial Earth observation satellite
.
on November 4, 1995 from Vandenberg AFB in California
, into a sun-synchronous orbit
(dawn-dusk) above the Earth with an altitude of 798 kilometers and inclination of 98.6 degrees. Developed under the management of the Canadian Space Agency (CSA) in cooperation with Canadian provincial governments and the private sector, it provides images of the Earth for both scientific and commercial applications. Radarsat-1's images are useful in many fields, including agriculture, cartography, hydrology, forestry, oceanography, geology, ice and ocean monitoring, arctic surveillance, and detecting ocean oil slicks.
) provided the Delta II
rocket to launch Radarsat-1 in exchange for access to its data. Estimates are that the project, excluding launch, cost $620 million (Canadian). The Canadian federal government contributed about $500 million, the four participating provinces (Quebec
, Ontario
, Saskatchewan
and British Columbia
) about $57 million, and the private sector about $63 million.
Radarsat International, Inc. (RSI), a Canadian private company, was created in 1989 to process, market and distribute Radarsat-1 data. (Radarsat International, Inc. (RSI) was later acquired by MacDonald Dettwiler and Associates
.) In 2006, RSI was rebranded MDA Geospatial Services International or MDA GSI
(SAR) sensor to image the Earth at a single microwave
frequency of 5.3 GHz, in the C band
(wavelength of 5.6 cm). Unlike optical satellites that sense reflected sunlight, SAR systems transmit microwave energy towards the surface and record the reflections. Thus, Radarsat-1 can image the Earth, day or night, in any atmospheric condition, such as cloud cover, rain, snow, dust or haze.
Each of Radarsat-1's seven beam modes offer a different image resolution. The modes include Fine, which covers an area of 50 km by 50 km (2500 km²) with a resolution of 10 meters; Standard, which covers an area of 100 km by 100 km (10,000 km²) and has a resolution of 30 meters; and ScanSAR wide, which covers a 500 km by 500 km (250,000 km²) area with a resolution of 100 meters. Radarsat-1 also has the unique ability to direct its beam at different angles.
and detecting changes at that location that took place during the 24 days. Using different beam positions, a location can also be scanned every few days.
Radarsat-1 is a right-looking satellite, meaning that microwave beam transmits and receives on the right side of the satellite, relative to its orbital path. As it descends in its orbit from the North Pole, it faces west, and when it ascends from the South Pole, it faces east. Locations can therefore be imaged from opposite sides. Combined with the different beam modes and positions, this provide users with many possible perspectives from which to image a location.
was launched on December 14, 2007 from Baikonur, Kazakhstan
Radarsat-1 covers the Arctic daily, and most of Canada every 72 hours depending on where the instruments are pointing, and what they are monitoring. It covers the entire Earth every 24 days.
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
's first commercial Earth observation satellite
Earth observation satellite
Earth observation satellites are satellites specifically designed to observe Earth from orbit, similar to reconnaissance satellites but intended for non-military uses such as environmental monitoring, meteorology, map making etc....
.
Mission
It was launched at 14h22 UTCCoordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
on November 4, 1995 from Vandenberg AFB in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, into a sun-synchronous orbit
Sun-synchronous orbit
A Sun-synchronous orbit is a geocentric orbit which combines altitude and inclination in such a way that an object on that orbit ascends or descends over any given point of the Earth's surface at the same local mean solar time. The surface illumination angle will be nearly the same every time...
(dawn-dusk) above the Earth with an altitude of 798 kilometers and inclination of 98.6 degrees. Developed under the management of the Canadian Space Agency (CSA) in cooperation with Canadian provincial governments and the private sector, it provides images of the Earth for both scientific and commercial applications. Radarsat-1's images are useful in many fields, including agriculture, cartography, hydrology, forestry, oceanography, geology, ice and ocean monitoring, arctic surveillance, and detecting ocean oil slicks.
History
National Aeronautics and Space Administration (NASANASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
) provided the Delta II
Delta II
Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...
rocket to launch Radarsat-1 in exchange for access to its data. Estimates are that the project, excluding launch, cost $620 million (Canadian). The Canadian federal government contributed about $500 million, the four participating provinces (Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
, Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, Saskatchewan
Saskatchewan
Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....
and British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
) about $57 million, and the private sector about $63 million.
Radarsat International, Inc. (RSI), a Canadian private company, was created in 1989 to process, market and distribute Radarsat-1 data. (Radarsat International, Inc. (RSI) was later acquired by MacDonald Dettwiler and Associates
MacDonald Dettwiler
MacDonald, Dettwiler and Associates Ltd. is a Richmond, British Columbia-based Canadian aerospace, information services and products company, employing over 3000 people throughout Canada, the United States and the United Kingdom, under the MDA brand name....
.) In 2006, RSI was rebranded MDA Geospatial Services International or MDA GSI
Payload
Radarsat-1 uses a Synthetic Aperture RadarSynthetic aperture radar
Synthetic-aperture radar is a form of radar whose defining characteristic is its use of relative motion between an antenna and its target region to provide distinctive long-term coherent-signal variations that are exploited to obtain finer spatial resolution than is possible with conventional...
(SAR) sensor to image the Earth at a single microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
frequency of 5.3 GHz, in the C band
C band
The C band is a name given to certain portions of the electromagnetic spectrum, including wavelengths of microwaves that are used for long-distance radio telecommunications. The IEEE C-band - and its slight variations - contains frequency ranges that are used for many satellite communications...
(wavelength of 5.6 cm). Unlike optical satellites that sense reflected sunlight, SAR systems transmit microwave energy towards the surface and record the reflections. Thus, Radarsat-1 can image the Earth, day or night, in any atmospheric condition, such as cloud cover, rain, snow, dust or haze.
Each of Radarsat-1's seven beam modes offer a different image resolution. The modes include Fine, which covers an area of 50 km by 50 km (2500 km²) with a resolution of 10 meters; Standard, which covers an area of 100 km by 100 km (10,000 km²) and has a resolution of 30 meters; and ScanSAR wide, which covers a 500 km by 500 km (250,000 km²) area with a resolution of 100 meters. Radarsat-1 also has the unique ability to direct its beam at different angles.
Constellation
With an orbital period of 100.7 minutes, Radarsat-1 circles the Earth 14 times a day. The orbit path repeats every 24 days, this means that the satellite is in exactly the same location and can take the same image (same beam mode and beam position) every 24 days. This is useful for interferometryInterferometric synthetic aperture radar
Interferometric synthetic aperture radar, also abbreviated InSAR or IfSAR, is a radar technique used in geodesy and remote sensing. This geodetic method uses two or more synthetic aperture radar images to generate maps of surface deformation or digital elevation, using differences in the phase of...
and detecting changes at that location that took place during the 24 days. Using different beam positions, a location can also be scanned every few days.
Radarsat-1 is a right-looking satellite, meaning that microwave beam transmits and receives on the right side of the satellite, relative to its orbital path. As it descends in its orbit from the North Pole, it faces west, and when it ascends from the South Pole, it faces east. Locations can therefore be imaged from opposite sides. Combined with the different beam modes and positions, this provide users with many possible perspectives from which to image a location.
Current status
On November 4, 2010, Radarsat-1 celebrated its 15 year service anniversary. It has outlived its planned five-year lifetime by a wide margin. Radarsat-2RADARSAT-2
Radarsat-2 is an Earth observation satellite that was successfully launched December 14, 2007 for the Canadian Space Agency by Starsem, using a Soyuz FG launch vehicle, from Kazakhstan's Baikonur Cosmodrome....
was launched on December 14, 2007 from Baikonur, Kazakhstan
Baikonur
Baikonur , formerly known as Leninsk, is a city in Kyzylorda Province of Kazakhstan, rented and administered by the Russian Federation. It was constructed to service the Baikonur Cosmodrome and was officially renamed Baikonur by Russian president Boris Yeltsin on December 20, 1995.The shape of the...
Radarsat-1 covers the Arctic daily, and most of Canada every 72 hours depending on where the instruments are pointing, and what they are monitoring. It covers the entire Earth every 24 days.