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Remote Sensing (oceanography)
Remote sensing in oceanography is a widely used Observational techniques, observational technique which enables researchers to acquire data of a location without physically measuring at that location. Remote sensing in oceanography mostly refers to measuring properties of the ocean surface with sensors on satellites or planes, which compose an image of captured electromagnetic radiation. A remote sensing instrument can either receive radiation from the Earth’s surface (passive), whether reflected from the Sun or emitted, or send out radiation to the surface and catch the reflection (active). All remote sensing instruments carry a sensor to capture the intensity of the radiation at specific wavelength windows, to retrieve a spectral signature for every location. The physical and chemical state of the surface determines the emissivity and reflectance for all bands in the electromagnetic spectrum, linking the measurements to physical properties of the surface. Unlike passive instrume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observational Techniques
In marketing and the social sciences, observational research (or field research) is a social research technique that involves the direct observation of phenomena in their natural setting. This differentiates it from experimental techniques, experimental research in which a quasi-artificial environment is created to control for spurious factors, and where at least one of the variables is manipulated as part of the experilovement. In context Observational research is a method of data collection that has become associated with qualitative research. Compared with quantitative marketing research, quantitative research and experimental techniques, experimental research, observational research tends to be less reliability (psychometric), reliable but often more validity (psychometric), valid. The main advantage of observational research is flexibility. The researchers can change their approach as needed. Observational research measures behavior directly, rather than the subject's self-re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landsat 1
Landsat 1 (LS-1), formerly named Earth Resources Technology Satellite ERTS-A or ERTS-1, was the first satellite of the United States' Landsat program. It was a modified version of the Nimbus 4 Meteorology, meteorological satellite and was launched on July 23, 1972, by a Delta 0100, Delta 900 rocket from Vandenberg Air Force Base in California. It was the first satellite to carry a Multispectral Scanner. The near-polar orbiting spacecraft served as a stabilized, Earth-oriented platform for obtaining information on agricultural and forestry resources, geology and mineral resources, hydrology and water resources, geography, cartography, environmental pollution, oceanography and marine resources, and meteorological phenomena. Background The multi-agency Earth Resources Satellites Program was begun in 1966 by the Department of the Interior. The goal of the program was to gather data from the Earth via remote sensing techniques. The following year a feasibility study was performed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jason-3
Jason-3 is a satellite altimeter created by a partnership of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and National Aeronautic and Space Administration (NASA), and is an international cooperative mission in which National Oceanic and Atmospheric Administration (NOAA) is partnering with the Centre National d'Études Spatiales (CNES, French space agency). The satellite's mission is to supply data for scientific, commercial, and practical applications to sea level rise, sea surface temperature, ocean temperature circulation, and climate change. Mission objectives Jason-3 makes precise measurements related to global sea-surface height. Because sea surface height is measured via altimetry, mesoscale ocean features are better simulated since the Jason-3 radar altimeter can measure global sea-level variations with very high accuracy. The scientific goal is to produce global sea-surface height measurements every 10 days to an accuracy o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OSTM/Jason-2
OSTM/Jason-2, or Ocean Surface Topography Mission/Jason-2 satellite, was an international Earth observation satellite altimeter joint mission for sea surface height measurements between NASA and CNES. It was the third satellite in a series started in 1992 by the NASA/CNES TOPEX/Poseidon mission and continued by the NASA/CNES Jason-1 mission launched in 2001. History Like its two predecessors, OSTM/Jason-2 used high-precision ocean altimetry to measure the distance between the satellite and the ocean surface to within a few centimeters. These very accurate observations of variations in sea surface height — also known as ocean topography — provide information about global sea level, the speed and direction of ocean currents, and heat stored in the ocean. Jason-2 was built by Thales Alenia Space using a Proteus platform, under a contract from CNES, as well as the main Jason-2 instrument, the Poseidon-3 altimeter (successor to the Poseidon and Poseidon 2 altimeter on-boar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jason-1
Jason-1 was a satellite altimeter oceanography mission. It sought to monitor global ocean circulation, study the ties between the ocean and the atmosphere, improve global climate forecasts and predictions, and monitor events such as El Niño and ocean eddies. Jason-1 was launched in 2001 and it was followed by OSTM/Jason-2 in 2008, and Jason-3 in 2016the Jason satellite series. Jason-1 was launched alongside the TIMED spacecraft. Naming The lineage of the name begins with the JASO1 meeting (JASO=Journées Altimétriques Satellitaires pour l'Océanographie) in Toulouse, France to study the problems of assimilating altimeter data in models. Jason as an acronym also stands for "Joint Altimetry Satellite Oceanography Network". Additionally, it is used to reference the mythical quest for knowledge of Jason and the Argonautsbr> [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TOPEX/Poseidon
TOPEX/Poseidon was a joint satellite altimeter mission between NASA, the U.S. space agency; and CNES, the French space agency, to map ocean surface topography. Launched on August 10, 1992, it was the first major oceanographic research satellite. TOPEX/Poseidon helped revolutionize oceanography by providing data previously impossible to obtain. Oceanographer Walter Munk described TOPEX/Poseidon as "the most successful ocean experiment of all time." A malfunction ended normal satellite operations in January 2006. Description Before TOPEX/Poseidon, scientists had only a brief glimpse of Earth's ocean as a whole from the pioneering but short-lived Seasat satellite. TOPEX/Poseidon's radar altimeter provided the first continuous global coverage of the surface topography of the oceans. From orbit 1,330 kilometers above Earth, TOPEX/Poseidon provided measurements of the surface height of 95 percent of the ice-free ocean to an accuracy of 3.3 centimeters. The satellite's measurements of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nimbus 7
Nimbus 7 (also called Nimbus G) was a meteorological satellite. It was the seventh and last in a series of the Nimbus program. Launch Nimbus 7 was launched on October 24, 1978, by a Delta rocket from Vandenberg Air Force Base, California, United States. The spacecraft functioned nominally until 1994. The satellite orbited the Earth once every 1 hour and 34 minutes, at an inclination of 99 degrees. Its perigee was and its apogee was . Mission The Nimbus 7 research and development satellite served as a stabilized, Earth-oriented platform for the testing of advanced systems for sensing and collecting data in the pollution, oceanographic, and meteorological disciplines. The polar-orbiting spacecraft consisted of three major structures: a hollow torus-shaped sensor mount, solar paddles, and a control housing unit that was connected to the sensor mount by a tripod truss structure. Configured somewhat like an ocean buoy, Nimbus 7 was nearly tall, in diameter at th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coastal Zone Color Scanner
The coastal zone color scanner (CZCS) was a multi-channel scanning radiometer aboard the Nimbus 7 satellite, predominately designed for water remote sensing. Nimbus 7 was launched 24 October 1978, and CZCS became operational on 2 November 1978. It was only designed to operate for one year (as a proof-of-concept), but in fact remained in service until 22 June 1986. Its operation on board the Nimbus 7 was limited to alternate days as it shared its power with the passive microwave scanning multichannel microwave radiometer. CZCS measured reflected solar energy in six channels, at a resolution of 800 meters. These measurements were used to map chlorophyll concentration in water, sediment distribution, salinity, and the temperature of coastal waters and ocean currents. CZCS lay the foundations for subsequent satellite ocean color sensors, and formed a cornerstone for international efforts to understand the ocean's role in the carbon cycle. Ocean color The most significant produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Surface Temperature
Sea surface temperature (or ocean surface temperature) is the ocean temperature, temperature of ocean water close to the surface. The exact meaning of ''surface'' varies in the literature and in practice. It is usually between and below the sea surface. Sea surface temperatures greatly modify air masses in the Atmosphere of Earth, Earth's atmosphere within a short distance of the shore. The thermohaline circulation has a major impact on average sea surface temperature throughout most of the world's oceans. Warm sea surface temperatures can develop and Tropical cyclogenesis, strengthen cyclones over the ocean. Tropical cyclones can also cause a cool wake. This is due to turbulent mixing of the upper of the ocean. Sea surface temperature changes during the day. This is like the air above it, but to a lesser degree. There is less variation in sea surface temperature on breezy days than on calm days. Coastal sea surface temperatures can cause offshore winds to generate upwelling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiometer
A radiometer or roentgenometer is a device for measuring the radiant flux (power) of electromagnetic radiation. Generally, a radiometer is an infrared radiation detector or an ultraviolet detector. Microwave radiometers operate in the microwave wavelengths. While the term ''radiometer'' can refer to any device that measures electromagnetic radiation (e.g. light), the term is often used to refer specifically to a Crookes radiometer ("light-mill"), a device invented in 1873 in which a rotor (having vanes which are dark on one side, and light on the other) in a partial vacuum spins when exposed to light. A common misbelief (one originally held even by Crookes) is that the momentum of the absorbed light on the black faces makes the radiometer operate. If this were true, however, the radiometer would spin away from the non-black faces, since the photons bouncing off those faces impart more momentum than the photons absorbed on the black faces. Photons do exert radiation press ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Microwave
Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300 MHz and 300 GHz, broadly construed. A more common definition in radio-frequency engineering is the range between 1 and 100 GHz (wavelengths between 30 cm and 3 mm), or between 1 and 3000 GHz (30 cm and 0.1 mm). In all cases, microwaves include the entire super high frequency, super high frequency (SHF) band (3 to 30 GHz, or 10 to 1 cm) at minimum. The boundaries between far infrared, terahertz radiation, microwaves, and ultra-high-frequency (UHF) are fairly arbitrary and differ between different fields of study. The prefix ' in ''microwave'' indicates that microwaves are small (having shorter wavelengths), compared to the radio waves used in prior radio technology. Frequencies in the micr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
