{"id":15122,"date":"2018-05-02T05:51:38","date_gmt":"2018-05-02T05:51:38","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=15122"},"modified":"2020-06-09T13:00:56","modified_gmt":"2020-06-09T13:00:56","slug":"moon-holds-key-to-improve-satellite-views-of-earth","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/moon-holds-key-to-improve-satellite-views-of-earth\/","title":{"rendered":"Moon holds key to improve satellite views of earth"},"content":{"rendered":"
\"\"
MSG images the Moon above Earth<\/figcaption><\/figure>\n

Many Earth observation satellites make use of an added ingredient to ensure reliable, good quality environmental data: the Moon.<\/span><\/p>\n

While the surface of the Earth is ever changing, the face of the Moon has stayed the same for millions of years, apart from occasional meteoroid impacts. This makes the light reflecting from the lunar surface an ideal calibration source for optical Earth-observing instruments. Now an ESA-led project has plans to make it more useful still.<\/span><\/p>\n

An instrument has been placed high on the slopes of Mount Teide in Tenerife, above the majority of clouds and airborne dust, designed to measure nightly variations in moonlight, to hone the accuracy of lunar calibration efforts in future.<\/span><\/p>\n

\u201cSpace agencies across the globe use the Moon to assess and monitor the calibration of optical Earth observation instruments,\u201d explains Marc Bouvet, overseeing the project for ESA. \u201cThese instruments are carefully calibrated before launch, but in space their performance can gradually drift, due to radiation or lens contamination for instance, or mechanical changes.<\/span><\/p>\n

\n
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Moon imaged by Pleiades satellite<\/figcaption><\/figure>\n

\u201cWe need to be sure that changes in the light received from Earth represent genuine changes on the ground versus changes in the instrument. Accordingly we need calibration targets \u2013 representing an unchanging, stable light source \u2013 to pinpoint any performance drift in space instrument measurements.\u201d<\/span><\/p>\n

Some missions incorporate internal calibration devices while others use relatively unchanging terrestrial features such as featureless stretches of desert, ocean or salt flats, modelling the radiation coming from these targets. But any location on Earth might still vary over time.<\/span><\/p>\n

\u201cCompared to anywhere on Earth, the surface of the Moon is changeless,\u201d adds Marc. \u201cSo a wide range of Earth observing missions use it for monitoring the stability of their calibration, whether from low-Earth or geostationary orbits.<\/span><\/p>\n<\/div>\n

\n

\u201cThe main issue, wherever we are looking from, is that the Moon we see isn\u2019t always the same Moon. It doesn\u2019t have a neatly circular orbit around the Earth \u2013 neither does Earth around the Sun \u2013 and across every 28 days of the lunar cycle we don\u2019t always see exactly the same face: sometimes we see more to the sides, or on top \u2013 known as lunar libration.<\/span><\/p>\n

\u201cIn fact, it takes 18 years for the Moon to return to the way it appeared before the present.<\/span><\/p>\n

\u201cOur objective is to observe the full disc of the Moon across a two-year period, to be able to create a model of lunar radiation that is much more accurate. Today\u2019s best modelling effort has a 10% uncertainty associated with it; we want to be able to get that down to around 2%.\u201d<\/span><\/p>\n

The instrument installed on Mount Teide is a solar photometer, similar to those used by a global network measuring particles in the atmosphere. This one, however, has been specially adapted to work during the night instead of the day, measuring moonlight instead.<\/span><\/p>\n

The project, backed through ESA\u2019s Basic Activities, is being undertaken by a consortium incorporating the UK\u2019s National Physical Laboratory, as well as Spain\u2019s Valladolid University and Belgium\u2019s VITO, the Flemish Institute for Technological Research.<\/span><\/p>\n

\u201cLast year there was a conference on lunar calibration, including participants from NASA, NOAA, French space agency CNES, Japanese space agency JAXA and China,\u201d adds Marc.<\/span><\/p>\n

\u201cThere was a lot of excitement about this project \u2013 as well as comparable US and Chinese efforts \u2013 because success would lead us to being able to link past, present and future optical Earth-observing missions to a common calibration reference, allowing easier cross-comparisons of data, enriching our overall picture of the terrestrial environment.<\/span><\/p>\n

\u201cWe hope the improved model could be ready for use by the end of the decade.\u201d<\/span><\/p>\n<\/div>\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

Many Earth observation satellites make use of an added ingredient to ensure reliable, good quality environmental data: the Moon. While the surface of the Earth is ever changing, the face of the Moon has stayed the same for millions of years, apart from occasional meteoroid impacts. This makes the light reflecting from the lunar surface […]<\/p>\n","protected":false},"author":6,"featured_media":15123,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[],"class_list":["post-15122","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-space-news"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",625,441,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large-300x212.jpg",300,212,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",625,441,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",625,441,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",625,441,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",625,441,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",625,441,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",625,441,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",600,423,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",600,423,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",625,441,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",510,360,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",92,65,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",625,441,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",96,68,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/05\/MSG_images_the_Moon_above_Earth_large.jpg",150,106,false]},"author_info":{"info":["Amrita Tuladhar"]},"category_info":"Space\/ AstroPhysics<\/a>","tag_info":"Space\/ AstroPhysics","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/15122","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=15122"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/15122\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/15123"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=15122"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=15122"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=15122"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}