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The Ocean Surface Topography Mission (OSTM) on the Jason-2 satellite〔(【引用サイトリンク】 Ocean Surface Topography from Space )〕 is an international Earth observation satellite mission that continues the sea surface height measurements begun in 1992 by the joint NASA/CNES TOPEX/Poseidon mission〔(【引用サイトリンク】 Ocean Surface Topography from Space )〕 and followed by the NASA/CNES Jason-1 mission launched in 2001.〔(【引用サイトリンク】 title =Ocean Surface Topography from Space )〕 ==History== Like its two predecessors, OSTM/Jason-2 uses 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-board TOPEX/Poseidon and Jason-1) Scientists consider the 15-plus-year climate data record that this mission will extend critical understanding how ocean circulation is linked to global climate change. OSTM/Jason-2 was launched at 07:46 UTC on June 20, 2008, from Space Launch Complex 2W at the Vandenberg Air Force Base in California, USA, by a Delta II 7320 rocket.〔(【引用サイトリンク】title=NASA Launches Ocean Satellite to Keep a Weather, Climate Eye Open )〕 The spacecraft separated from the rocket 55 minutes later.〔(【引用サイトリンク】title=Jason-2 successfully launched )〕 It is now in a circular, non-sun-synchronous orbit at an inclination of 66 degrees to Earth's equator, allowing it to monitor 95 percent of Earth's ice-free ocean every 10 days. Jason-1 has been moved to the opposite side of Earth and now flies over the same region of the ocean that Jason-2 flew over five days earlier.〔(【引用サイトリンク】 Tandem Mission Brings Ocean Currents into Sharper Focus )〕 Jason-1's ground tracks fall mid-way between those of Jason-2, which are about apart at the equator. This interleaved tandem mission provides twice the number of measurements of the ocean's surface, bringing smaller features such as ocean eddies into view. The tandem mission also helps pave the way for a future ocean altimeter mission that would collect much more detailed data with its single instrument than the two Jason satellites now do together. With OSTM/Jason-2, ocean altimetry makes the transition from research into operational mode. Responsibility for collecting these measurements moves from the space agencies to the world’s weather and climate forecasting agencies, which use them for short-range, seasonal, and long-range weather and climate forecasting.〔(【引用サイトリンク】title= NOAA takes over Jason-2 satellite operations )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ocean Surface Topography Mission」の詳細全文を読む スポンサード リンク
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