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TOPEX
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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remote Sensing
Remote sensing is the acquisition of information about an physical object, object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Earth and other planets. Remote sensing is used in numerous fields, including geophysics, geography, land surveying and most Earth science disciplines (e.g. exploration geophysics, hydrology, ecology, meteorology, oceanography, glaciology, geology). It also has military, intelligence, commercial, economic, planning, and humanitarian applications, among others. In current usage, the term ''remote sensing'' generally refers to the use of satellite- or airborne-based sensor technologies to detect and classify objects on Earth. It includes the surface and the atmosphere and oceans, based on wave propagation, propagated signals (e.g. electromagnetic radiation). It may be split into "active" remote sensing (when a signal is emitted b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Level
Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised geodetic datumthat is used, for example, as a chart datum in cartography and Navigation, marine navigation, or, in aviation, as the standard sea level at which atmospheric pressure is measured to Calibration, calibrate altitude and, consequently, aircraft flight levels. A common and relatively straightforward mean sea-level standard is instead a long-term average of tide gauge readings at a particular reference location. The term ''above sea level'' generally refers to the height above mean sea level (AMSL). The term APSL means above present sea level, comparing sea levels in the past with the level today. Earth's radius at sea level is 6,378.137 km (3,963.191 mi) at the equator. It is 6,356.752 km (3,94 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Surface Topography Mission
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] |
El Niño Southern Oscillation
EL, El or el may refer to: Arts and entertainment Fictional entities * El, a character from the manga series ''Shugo Chara!'' by Peach-Pit * Eleven (''Stranger Things'') (El), a fictional character in the TV series ''Stranger Things'' * El, family name of Kal-El (Superman) and his father Jor-El in the Superman dynasty * E.L. Faldt, character in the road comedy film '' Road Trip'' Music * Él Records, an independent record label from the UK founded by Mike Alway * ''Él ''(Lucerito album), a 1982 album by Lucerito * "Él", Spanish song by Rubén Blades from the album '' Caminando'' * "Él" (Lucía song), the Spanish entry performed by Lucía in the Eurovision Song Contest 1982 Other media * ''Él'', 1926 autobiographical novel by Mercedes Pinto * ''Él'' (film), a 1953 film by Luis Buñuel based on the 1926 novel * ''Él'' (visual novel), a 1991 Japanese adult visual novel * EL TV, an Azerbaijani regional television channel Companies and organizations * Estée Lauder Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Momentum Wheel
A reaction wheel (RW) is an electric motor attached to a flywheel, which, when its rotation speed is changed, causes a counter-rotation proportionately through Angular momentum#Conservation of angular momentum, conservation of angular momentum. A reaction wheel can rotate only around its center of mass; it is not capable of moving from one place to another (translation (physics), translational force). Reaction wheels are used primarily by spacecraft for three-axis Spacecraft attitude control, attitude control, and do not require Rocket engine, rockets or external applicators of torque, which reduces the payload fraction, mass fraction needed for fuel. They provide a high pointing accuracy, and are particularly useful when the spacecraft must be rotated by very small amounts, such as keeping a telescope pointed at a star. A reaction wheel is sometimes operated at a constant (or near-constant) rotation speed, to provide a satellite with a large amount of stored angular momentum. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poseidon
Poseidon (; ) is one of the twelve Olympians in ancient Greek religion and mythology, presiding over the sea, storms, earthquakes and horses.Burkert 1985pp. 136–139 He was the protector of seafarers and the guardian of many Hellenic cities and colonies. In pre-Olympian Bronze Age Greece, Poseidon was venerated as a chief deity at Pylos and Thebes, with the cult title "earth shaker"; in the myths of isolated Arcadia, he is related to Demeter and Persephone and was venerated as a horse, and as a god of the waters.Seneca quaest. Nat. VI 6 :Nilsson Vol I p.450 Poseidon maintained both associations among most Greeks: he was regarded as the tamer or father of horses, who, with a strike of his trident, created springs (the terms for horses and springs are related in the Greek language).Nilsson Vol I p.450 His Roman equivalent is Neptune. Homer and Hesiod suggest that Poseidon became lord of the sea when, following the overthrow of his father Cronus, the world was divided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greece
Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically related city-states and communities. Prior to the Roman period, most of these regions were officially unified only once under the Kingdom of Macedon from 338 to 323 BC. In Western history, the era of classical antiquity was immediately followed by the Early Middle Ages and the Byzantine period. Three centuries after the decline of Mycenaean Greece during the Bronze Age collapse, Greek urban poleis began to form in the 8th century BC, ushering in the Archaic period and the colonization of the Mediterranean Basin. This was followed by the age of Classical Greece, from the Greco-Persian Wars to the death of Alexander the Great in 323 BC, and which included the Golden Age of Athens and the Peloponnesian War. The u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Guiana
French Guiana, or Guyane in French, is an Overseas departments and regions of France, overseas department and region of France located on the northern coast of South America in the Guianas and the West Indies. Bordered by Suriname to the west and Brazil to the east and south, French Guiana covers a total area of and a land area of . As of January 2025, it is home to 292,354 people. French Guiana is the second-largest Regions of France, region in France, being approximately one-seventh the size of metropolitan France, European France, and the largest Special member state territories and the European Union, outermost region within the European Union. It has a very low population density, with only . About half of its residents live in its capital, Cayenne. Approximately 98.9% of French Guiana is covered by forests, much of it Old-growth forest, primeval Tropical rainforest, rainforest. Guiana Amazonian Park, the largest national park in the European Union covers 41% of French ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kitsat-1
KITSAT-1 or KITSAT-A (Korean Institute of Technology Satellite) is the first South Korean satellite to be launched. Once launched, the satellite was given the nickname "Our Star" ( 우리별). KITSAT-1 operated in a by low Earth orbit (LEO). Of the 12 satellites launched by South Korea, KITSAT-1 is in the highest orbit. While KITSAT-1 maintains equilibrium by gravity gradient forces, magnetic torque can be used to control attitude if needed. The forecasted lifespan of KITSAT-1 was only five years, but communication with the satellite was maintained for 12 years. Since the launch of KITSAT-1, South Korea launched an additional 36 satellites by 2020. Description KITSAT-1 is considered to be a smallsat or microsatellite. KITSAT-1 is the smallest low Earth orbit satellite that has been launched by South Korea. Instruments KITSAT-1's on-board computer (OBC) system uses an OBC186 for the main OBC and an OBC80 as the backup on-board computer system. KITSAT-1 carried a Digital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expendable Launch Vehicle
An expendable launch system (or expendable launch vehicle/ELV) is a launch vehicle that can be launched only once, after which its components are destroyed during reentry or impact with Earth, or discarded in space. ELVs typically consist of several rocket stages that are discarded sequentially as their fuel is exhausted and the vehicle gains altitude and speed. As of 2024, fewer and fewer satellites and human spacecraft are launched on ELVs in favor of reusable launch vehicles. However, there are many instances where a ELV may still have a compelling use case over a reusable vehicle. ELVs are simpler in design than reusable launch systems and therefore may have a lower production cost. Furthermore, an ELV can use its entire fuel supply to accelerate its payload, offering greater payloads. ELVs are a proven technology in widespread use for many decades. Current operators Arianespace China ISRO During the 1960s and 1970s, India initiated its own launch vehicle program ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Decadal Oscillation
The Pacific decadal oscillation (PDO) is a robust, recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20°N. Over the past century, the amplitude of this climate pattern has varied irregularly at interannual-to-interdecadal time scales (meaning time periods of a few years to as much as time periods of multiple decades). There is evidence of reversals in the prevailing polarity (meaning changes in cool surface waters versus warm surface waters within the region) of the oscillation occurring around 1925, 1947, and 1977; the last two reversals corresponded with dramatic shifts in salmon production regimes in the North Pacific Ocean. This climate pattern also affects coastal sea and continental surface air temperatures from Alaska to California. During a " warm", or "positive", phase, the west Pacific becomes cooler and part of the eastern ocean warm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
