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For his 57e beginning of the year, SpaceXSpaceX will carry a Franco-American satellite SwatSwat (Surface water ocean landscape), built under the responsibility of Thales Alenia Space. Satellite launch, a Hawk 9, will be conducted from Vandenberg Air Force Base, California. Main site LauncherLauncher It flew five times. So this is its sixth iteration.
SpaceX delays SWOT release to Friday
The take-off, originally scheduled for December 15, 2022, was postponed by 24 hours to Friday, December 16. the windowthe window The 10-minute kickoff starts at 12:46pm Paris time. The satellite is installed in a 77.6° inclined orbit at an altitude of 890 km and has a repeat operation of 20.86 days, for at least three years. From this height, Swat Creates a complete map every 10 days, unpublished today, of the topography of ocean and continental water surfaces at Earth scale!
Watch interviews with Sophie Goodin-Faye and Nicolas Pigot below to find out all about the “revolutionary” work.
Follow the launch of the SWAT satellite live. © CNN, Youtube
The article Remy DeCourtRemy DeCourt Published on 11/12/2022
A few days before the planned launch of the SWAT satellite on December 15th, we met with its leader, Sophie Goodin-Fay.AltimetryAltimetry, and Nicolas Picot, Swot Downstream Project Manager. These two Cnes engineers enlighten us on the aims of this work, which they do not hesitate to describe as “technically spectacular” and “scientifically revolutionary”.
In August 1992, The NASANASA and Cnes are launched Topex-PoseidonIt marks its beginningPrecision space altimetry, no one imagined that this discipline would revolutionize knowledge of the ocean. Even better, with the unprecedented ability to measure the height of the oceans to the nearest centimeter, scientists quickly realized they had a good indicator. Climate changeClimate change Over a long period of time.
Thirty years later, the SWOT satellite is about to change the space altimeter dimension with the launch of CINESE and NASA. In continuation of previous altimetry satellites, this mission will open a new era” Monitoring the continent’s surface water, lakes and rivers with a revolutionary perspectiveHydrologyHydrology Continent and Oceanography Sophie Coutin-Faye, head of the altimetry department at Cnes, and Nicolas Picot, Swot downstream project manager at Cnes, explained.
To do this, the satellite has breakthrough technology that will revolutionize knowledge of the water cycle at the planetary scale: “ Lakes, rivers, reservoirs and oceans… 90% of the Earth’s surface water will be explored ResolutionResolution Unrivaled! If space altimetry started showing interest in continental water and ice many years ago, especially from the Jason-2 and EnVISAT missions, we change the dimension with SWAT. Through the current works, there is vision NadirNadir and centimeter performance in oceans, decimeter performance in continental waters; With SWOT, view ” Looks spectacular “.
Swat observes all the water on Earth’s surface
Thanks, Karin, for the two radar antennas located at the ends of the 10m mast Measurements can be made‘Current altimetry radars measure a swath 120 km wide vertically from the satellite (nadir view). “. This wide passage in the ground is ” Spatial field of states d‘Water of rivers more than 100 meters wide, as well as lakes and estuaries‘Surface inundation greater than 250 m x 250 m with decimeter accuracy for water bodies of 1 km size2and measure slopes with an accuracy of l‘1.7 cm/km order “.
In other words, by observing both “ Area, height and gradient of rivers, Swat Rivers can be seen in 3D ! These parameters are necessary to calculate the information AttachmentsAttachments Variations in the size of rivers, or lakes, ” Poorly rated on a planetary scale “. In the oceans, the The instrument’s two-dimensional view and its precision will increase the ability to observe small-scale oceanic phenomena that play a key role in heat exchanges between the ocean and the atmosphere by a factor of 10. “.
“SWOT work should lead us to a better understanding of the water cycle on a global scale“
The SWAT-Mission It should lead us to a better understanding of the water cycle‘Globally “. In addition, observing and understanding distribution Water resources and their variations” It is necessary to address not only scientific but also social and economic challenges “.
To understand the excitement of the two engineers, you have to realize that the Earth is approximately 71% covered in water. The largest volume (97.5%) is salt water “.l’Clean waterClean water In very low amounts (2.5%), mainly “ Contained in glaciersIn Pole capsPole caps and underground, aquifers “. Of this 2.5% only 1% (so 0.025%) is in soil, lakes and rivers. Directly available and exploitable for the vital needs of all forms of life “. However, this circulation of water Yet the flows are poorly known and poorly measured, so we expect a revolution “.
The SWOT task was shortened to under three minutes. © NASA, CNES, CSA
That’s the whole point of the SWAT mission, one of which is ” ‘To understand better Water cycle The rainfall cycle is a good measure of evaporation over land, mainly oceans, and the amount of water entering the oceans from rivers. “, in order to allow the best” forecast ClimateClimate and fine-tuning of the planet’s water resources (consumption and human activities, etc‘Agriculture‘Urbanization, manufacturingHydroelectric powerHydroelectric powerriver navigation, etc.).
An unprecedented mission to study the topography of the oceans
In maritime sector, there is no SWAT” Not satisfied with the continuation of the proceedings Sea and sea level “. With its unprecedented altimetric performance, SWOT will reveal details unseen to date. With conventional nadir altimetry, the ocean is described with spatial scales close to 200 km. However, SWOT and its CARIN interferometric radar will provide access to ” With small spatial scales and global coverage » Therefore Describes mesoscale and sub-mesoscale ocean circulation down to 15 km spatial resolution. !
For sure and for the first time, SWAT must deliver ” Data on energy transfers between the ocean and AtmosphereAtmosphere They are mainly concerned with small-scale processes. These ocean circulation processes ” The ocean is a major reservoir of kinetic energy and therefore plays an important role in carbon and transport NutrientsNutrients So, in an increasingly warming world, a better understanding of these phenomena is critical to understanding the future of climate change.
Finally, SWOT is also a mission.” A technical demonstration with unprecedented use of a wide-swath interferometric altimeter that, if convincing to the user community, will inspire the design of the European Copernicus project’s Sentinel 3 NG topo mission. “.
In the 90s, Topex PoseidonTopex Poseidon ” It was a revolution in understanding‘the sea “. In a few years, ” We would say the same Swat “Sophie Goodin-Fay and Nicolas Pigot conclude.
