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Space-based Radar
Space-based radar or spaceborne radar is a radar operating in outer space; orbiting radar is a radar in orbit and Earth orbiting radar is a radar in geocentric orbit. A number of Earth-observing satellites, such as RADARSAT, have employed synthetic aperture radar (SAR) to obtain terrain and land-cover information about the Earth. Military In the United States, Discoverer II was a proposed military space-based radar program initiated in February 1998 as a joint Air Force, DARPA, and National Reconnaissance Office, NRO program. The concept was to provide high-range-resolution ground moving target indication (GMTI), as well as SAR imaging and high-resolution digital mapping. This program was cancelled by Congress in 2007. SBR is a less-ambitious version of Discoverer II. Space-based radar (SBR) is a proposed constellation of active radar satellites for the United States Department of Defense. The SBR system would allow detection and tracking of aircraft, ocean-going vessels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
US-A
Upravlyaemy Sputnik Aktivnyy ( for Controlled Active Satellite), or US-A, also known in the Western world as Radar Ocean Reconnaissance Satellite or RORSAT ( GRAU index 17F16K), was a series of 33 Soviet reconnaissance satellites. Launched between 1967 and 1988 to monitor NATO and merchant vessels using radar, the satellites were powered by nuclear reactors. Because a return signal from an ordinary target illuminated by a radar transmitter diminishes as the inverse of the fourth power of the distance, for the surveillance radar to work effectively, US-A satellites had to be placed in low Earth orbit. Had they used large solar panels for power, the orbit would have rapidly decayed due to drag through the upper atmosphere. Further, the satellite would have been useless in the shadow of Earth. Hence the majority of the satellites carried type BES-5 nuclear reactors fuelled by uranium-235. Normally the nuclear reactor cores were ejected into high orbit (a so-called "disposal orbit") ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Scatterometer
A scatterometer or diffusionmeter is a scientific instrument to measure the return of a beam of light or radar waves scattered by diffusion in a medium such as air. Diffusionmeters using visible light are found in airports or along roads to measure horizontal visibility. Radar scatterometers use radio or microwaves to determine the normalized radar cross section (σ0, "sigma zero" or "sigma naught") of a surface. They are often mounted on weather satellites to find wind speed and direction, and are used in industries to analyze the roughness of surfaces. Optical Optical diffusionmeters are devices used in meteorology to find the optical range or the horizontal visibility. They consist of a light source, usually a laser, and a receiver. Both are placed at a 35° angle downward, aimed at a common area. Lateral scattering by the air along the light beam is quantified as an attenuation coefficient. Any departure from the clear air extinction coefficient (e.g. in fog) is measured a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Radar Altimeter
A radar altimeter (RA), also called a radio altimeter (RALT), electronic altimeter, reflection altimeter, or low-range radio altimeter (LRRA), measures altitude above the terrain presently beneath an aircraft or spacecraft by timing how long it takes a beam of radio waves to travel to ground, reflect, and return to the craft. This type of altimeter provides the distance between the antenna and the ground directly below it, in contrast to a barometric altimeter which provides the distance above a defined vertical datum, usually mean sea level. Principle As the name implies, radar (radio detection and ranging) is the underpinning principle of the system. The system transmits radio waves down to the ground and measures the time it takes them to be reflected back up to the aircraft. The altitude above the ground is calculated from the radio waves' travel time and the speed of light. Radar altimeters required a simple system for measuring the time-of-flight that could be displayed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Seasat
Seasat was the first Earth-orbiting satellite designed for remote sensing of the Earth's oceans and had on board one of the first spaceborne synthetic-aperture radar (SAR). The mission was designed to demonstrate the feasibility of global satellite monitoring of oceanographic phenomena and to help determine the requirements for an operational ocean remote sensing satellite system. Specific objectives were to collect data on sea-surface winds, sea-surface temperatures, wave heights, internal waves, atmospheric water, sea ice features and ocean topography. Seasat was managed by NASA's Jet Propulsion Laboratory and was launched on 27 June 1978 into a nearly circular orbit with an inclination of 108°. Seasat operated until 10 October 1978 (UTC), when a massive short circuit in the Agena-D bus electrical system ended the mission. Instruments Seasat carried five major instruments designed to return the maximum information from ocean surfaces: # Radar altimeter to measure spacecraf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Jet Propulsion Laboratory
The Jet Propulsion Laboratory (JPL) is a Federally funded research and development centers, federally funded research and development center (FFRDC) in La Cañada Flintridge, California, Crescenta Valley, United States. Founded in 1936 by California Institute of Technology (Caltech) researchers, the laboratory is now owned and sponsored by NASA and administered and managed by Caltech. The primary function of the laboratory is the construction and operation of planetary robotic spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating the NASA Deep Space Network (DSN). Among the major active projects at the laboratory, some are the Mars 2020 mission, which includes the ''Perseverance (rover), Perseverance'' rover; the Mars Science Laboratory mission, including the ''Curiosity (rover), Curiosity'' rover; the ''Mars Reconnaissance Orbiter''; the ''Juno (spacecraft), Juno'' spacecraft orbiting Jupiter; the ''Soil Moisture Active P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States's civil list of government space agencies, space program, aeronautics research and outer space, space research. National Aeronautics and Space Act, Established in 1958, it succeeded the National Advisory Committee for Aeronautics (NACA) to give the American space development effort a distinct civilian orientation, emphasizing peaceful applications in space science. It has since led most of America's space exploration programs, including Project Mercury, Project Gemini, the 1968–1972 Apollo program missions, the Skylab space station, and the Space Shuttle. Currently, NASA supports the International Space Station (ISS) along with the Commercial Crew Program and oversees the development of the Orion (spacecraft), Orion spacecraft and the Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Earth Observation
Earth observation (EO) is the gathering of information about the physical, chemical, and biosphere, biological systems of the planet Earth. It can be performed via remote sensing, remote-sensing technologies (Earth observation satellites) or through direct-contact sensors in ground-based or airborne platforms (such as weather stations and weather balloons, for example). According to the Group on Earth Observations (GEO), the concept encompasses both "space-based or remotely-sensed data, as well as ground-based or In situ#Earth and atmospheric sciences, in situ data". Earth observation is used to monitor and assess the status of and changes in natural environment, natural and built environments. Terminology In Europe, ''Earth observation'' has often been used to refer to satellite-based remote sensing, but the term is also used to refer to any form of observations of the Earth system, including in situ and airborne observations, for example. The GEO, which has over 100 member coun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
COSMO-SkyMed
COSMO-SkyMed (COnstellation of small Satellites for the Mediterranean basin Observation) is an Earth-observation satellite space-based radar system funded by the Italian Ministry of Research and Ministry of Defence and conducted by the Italian Space Agency (ASI), intended for both military and civilian use. The prime contractor for the spacecraft was Thales Alenia Space. COSMO SkyMed is a constellation of four dual use Intelligence, surveillance, target acquisition, and reconnaissance (ISR) Earth observation satellites with a synthetic-aperture radar (SAR) as main payload, the result of the intuition of Giorgio Perrotta in the early nineties. The synthetic-aperture radar was developed starting in the late nineties with the SAR 2000 program funded by ASI. The space segment of the system includes four identical medium-sized satellites called COSMO-SkyMed (or COSMO) 1, 2, 3, 4, equipped with synthetic-aperture radar (SAR) sensors with global coverage of the planet. Observati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Huanjing (satellite)
China plans to launch eleven Huanjing () satellites for disaster and environmental monitoring ("huanjing" is Chinese for "environment"). The satellites will be capable of visible, infrared, multi-spectral and synthetic-aperture radar imaging. The first two satellites, Huanjing-1A and Huanjing-1B, were launched on 6 September 2008 on a Long March 2C rocket from the Taiyuan Satellite Launch Center. In a report dated 3 September 2008, the Associated Press of Pakistan indicated the launch would be conducted 5 September 2008 using a Long March 2C launch vehicle. On 5 September 2008, Aviation Week reported the first launch would be of optical imaging satellites. Huanjing-1C was launched on 16 November 2012 on a Long March 2C rocket from the Taiyuan Satellite Launch Center. It is the first civilian Chinese remote sensing satellite to use a synthetic-aperture radar as imaging instrument. This S-band synthetic-aperture radar (SAR) was manufactured in Russia by NPO Mashinostroyeniya. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
SAR-Lupe
SAR-Lupe is Germany's first reconnaissance satellite system and is used for military purposes. SAR is an abbreviation for synthetic-aperture radar, and "Lupe" is German for magnifying glass. The SAR-Lupe program consists of five identical (770 kg) satellites, developed by the German aeronautics company OHB-System, which are controlled by a ground stationSAR-Lupe ground station: Zentrum für Nachrichtenwesen der Bundeswehr (ZNBw), Max-Planck-Str. 17, 53501 Gelsdorf . responsible for controlling the system and analysing the retrieved data. A large data archive of images will be kept in a former Cold War bunker belonging to the (Strategic Reconnaissance Command) of the Bundeswehr. The total price of the satellites was over 250 million Euro. Specifications SAR-Lupe's "high-resolution" images can be acquired day or night through all weather conditions. The satellites are able to provide up-to-date imagery from almost all regions of the world. The first satellite was lau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Information Gathering Satellite
are the satellites of the Japanese spy satellite program. It was started as a response to the 1998 North Korean missile test over Japan. The satellite program's main mission is to provide early warning of impending hostile launches in the region. This program is under the direct control of the cabinet. All Information Gathering Satellites have been launched by H-IIA rockets from the Tanegashima Space Center. History On 28 March 2003, presumably partly in response to North Korea's launch of a Taepodong-1 missile over Japan in 1998, and partly to provide a source of satellite images other than through cooperation with the US, where the US charged roughly US$10,000 for each satellite image, Japan launched a radar and an optical spy satellite A reconnaissance satellite or intelligence satellite (commonly, although unofficially, referred to as a spy satellite) is an Earth observation satellite or communications satellite deployed for military or intelligence applications. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
