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Pléiades (satellite)
The Pléiades constellation is composed of two very-high-resolution optical Earth-imaging satellites. Pléiades-1A and Pléiades-1B provide the coverage of Earth's surface with a repeat cycle of 26 days. Designed as a dual civil/military system, Pléiades will meet the space imagery requirements of European defence as well as civil and commercial needs. History The Pléiades system was designed under the French-Italian ORFEO Programme (Optical and Radar Federated Earth Observation) between 2001 and 2003. The Pléiades programme was launched in October 2003 with CNES (the French space agency) as the overall system prime contractor and EADS Astrium as the prime contractor for the space segment. Spot Image is the official and exclusive worldwide distributor of Pléiades products and services under a delegated public service agreement. Launches * Pléiades-1A was launched via a Russian Soyuz ST-A launch vehicle of the Centre Spatial Guyanais, Kourou, French Guiana, on 17 D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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] |
Oceania
Oceania ( , ) is a region, geographical region including Australasia, Melanesia, Micronesia, and Polynesia. Outside of the English-speaking world, Oceania is generally considered a continent, while Mainland Australia is regarded as its continental landmass. Spanning the Eastern Hemisphere, Eastern and Western Hemisphere, Western hemispheres, at the centre of the land and water hemispheres, water hemisphere, Oceania is estimated to have a land area of about and a population of around 46.3 million as of 2024. Oceania is the smallest continent in land area and the list of continents and continental subregions by population, second-least populated after Antarctica. Oceania has a diverse mix of economies from the developed country, highly developed and globally competitive market economy, financial markets of Australia, French Polynesia, Hawaii, New Caledonia, and New Zealand, which rank high in quality of life and Human Development Index, to the much least developed countries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilisations. Its 4.7 billion people constitute roughly 60% of the world's population. Asia shares the landmass of Eurasia with Europe, and of Afro-Eurasia with both Europe and Africa. In general terms, it is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a social constructionism, historical and cultural construct, as there is no clear physical and geographical separation between them. A commonly accepted division places Asia to the east of the Suez Canal separating it from Africa; and to the east of the Turkish straits, the Ural Mountains an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Americas
The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a single continent, the Americas or America is the 2nd largest continent by area after Asia, and is the 3rd largest continent by population. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. Along with their Lists of islands of the Americas, associated islands, the Americas cover 8% of Earth's total surface area and 28.4% of its land area. The topography is dominated by the American Cordillera, a long chain of mountains that runs the length of the west coast. The flatter eastern side of the Americas is dominated by large river basins, such as the Amazon basin, Amazon, St. Lawrence River–Great Lakes, Mississippi River System, Mississippi, and Río de la Plata Basin, La Plata basins. Since the Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle East
The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq. The term came into widespread usage by the United Kingdom and western European nations in the early 20th century as a replacement of the term Near East (both were in contrast to the Far East). The term "Middle East" has led to some confusion over its changing definitions. Since the late 20th century, it has been criticized as being too Eurocentrism, Eurocentric. The region includes the vast majority of the territories included in the closely associated definition of West Asia, but without the South Caucasus. It also includes all of Egypt (not just the Sinai Peninsula, Sinai) and all of Turkey (including East Thrace). Most Middle Eastern countries (13 out of 18) are part of the Arab world. The list of Middle Eastern countries by population, most populous countries in the region are Egypt, Turkey, and Iran, whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surface area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With nearly billion people as of , it accounts for about of the world's human population. Demographics of Africa, Africa's population is the youngest among all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Based on 2024 projections, Africa's population will exceed 3.8 billion people by 2100. Africa is the least wealthy inhabited continent per capita and second-least wealthy by total wealth, ahead of Oceania. Scholars have attributed this to different factors including Geography of Africa, geography, Climate of Africa, climate, corruption, Scramble for Africa, colonialism, the Cold War, and neocolonialism. Despite this lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerguelen Island
The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the sub-Antarctic region. They are among the most isolated places on Earth, with the closest territory being the Heard Island and McDonald Islands territory of Australia located at roughly , and the nearest inhabited territory being Madagascar at more than in distance. The islands, along with Adélie Land, the Crozet Islands, Amsterdam and Saint Paul islands, and France's Scattered Islands in the Indian Ocean, are part of the French Southern and Antarctic Lands and are administered as a separate district. The islands constitute one of the two exposed parts of the Kerguelen Plateau (the other being Heard Island and the McDonald islands), a large igneous province mostly submerged in the southern Indian Ocean. The main island, Grande Terre, is in area, about three-quarters of the size of Corsica, and is surrounded by a further 300 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweden
Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic country by both area and population, and is the List of European countries by area, fifth-largest country in Europe. Its capital and largest city is Stockholm. Sweden has a population of 10.6 million, and a low population density of ; 88% of Swedes reside in urban areas. They are mostly in the central and southern half of the country. Sweden's urban areas together cover 1.5% of its land area. Sweden has a diverse Climate of Sweden, climate owing to the length of the country, which ranges from 55th parallel north, 55°N to 69th parallel north, 69°N. Sweden has been inhabited since Prehistoric Sweden, prehistoric times around 12,000 BC. The inhabitants emerged as the Geats () and Swedes (tribe), Swedes (), who formed part of the sea-faring peopl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kiruna
(; ; ; ) is the northernmost Stad (Sweden), city in Sweden, situated in the province of Lapland, Sweden, Lapland. It had 17,002 inhabitants in 2016 and is the seat of Kiruna Municipality (population: 23,167 in 2016) in Norrbotten County. The city was originally built in the 1890s to serve the Kiruna Mine. The Esrange Space Center was established in Kiruna in the 1960s. Also in Kiruna are the Institute of Space Physics (Sweden), Institute of Space Physics and Luleå University of Technology's Department of Space Science. History Origins Archaeological findings have shown that the region around Kiruna has been inhabited for at least 6,000 years. Centuries before Kiruna was founded in 1900, the presence of iron ore at Kiirunavaara and Luossavaara had been known by the local Sámi people, Sámi population. In 1696, Samuel Mört, a bookkeeper of the Kengis works, wrote on rumours about the presence of iron in the two hills.Kummu 1997, p. 96. The ore became better known afte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toulouse
Toulouse (, ; ; ) is a city in southern France, the Prefectures in France, prefecture of the Haute-Garonne department and of the Occitania (administrative region), Occitania region. The city is on the banks of the Garonne, River Garonne, from the Mediterranean Sea, from the Atlantic Ocean and from Paris. It is the List of communes in France with over 20,000 inhabitants, fourth-largest city in France after Paris, Marseille and Lyon, with 511,684 inhabitants within its municipal boundaries (2022); its Functional area (France), metropolitan area has a population of 1,513,396 inhabitants (2022). Toulouse is the central city of one of the 22 Métropole, metropolitan councils of France. Between the 2014 and 2020 censuses, its metropolitan area was the third fastest growing among metropolitan areas larger than 500,000 inhabitants in France. Toulouse is the centre of the European aerospace industry, with the headquarters of Airbus, the SPOT (satellites), SPOT satellite system, ATR ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Moment Gyroscope
A control moment gyroscope (CMG) is an attitude control device generally used in spacecraft attitude control systems. A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotor’s angular momentum. As the rotor tilts, the changing angular momentum causes a gyroscopic torque that rotates the spacecraft. Comparison with Reaction Wheels CMGs and reaction wheels are two common types of spacecraft attitude control actuators and serve the same function, though they differ in mechanics and performance characteristics. The latter apply torque simply by changing rotor spin speed, but the former tilt the rotor's spin axis without necessarily changing its spin speed. CMGs are more mechanically complex than reaction wheels and typically more expensive, but are far more power efficient. For a few hundred watts and about 100 kg of mass, large CMGs have produced thousands of newton meters of torque. A reaction wheel of similar capability would require meg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
