NASA engineers have built a stopwatch that can measure accurately fraction of a billionth of a second.
\nThe timer is to be used for the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) scheduled for launch in 2018, NASA said.<\/p>\n
ICESat-2 will use six green laser beams to measure height. With its incredibly precise time measurements, scientists can calculate the distance between the satellite and the Earth below, and from there record precise height measurements of sea ice, glaciers, ice sheets, forests and the rest of the planet\u2019s surfaces.<\/p>\n
\u201cLight moves really, really fast, and if you\u2019re going to use it to measure something to a couple of centimetres, you\u2019d better have a really, really good clock,\u201d said Tom Neumann, ICESat-2\u2019s Deputy Project Scientist.<\/p>\n
If its stopwatch kept time even to a highly accurate millionth of a second, ICESat-2 could only measure elevation to within about 500 feet.<\/p>\n
Scientists would not be able to tell the top of a five-storey building from the bottom. That does not cut it when the goal is to record even subtle changes as ice sheets melt or sea ice thins.<\/p>\n
To reach the needed precision of a fraction of a billionth of a second, engineers at NASA\u2019s Goddard Space Flight Center in Greenbelt, Maryland, had to develop and build their own series of clocks on the satellite\u2019s instrument\u2014the Advanced Topographic Laser Altimeter System, or ATLAS.<\/p>\n
This timing accuracy will allow researchers to measure heights to within about two inches, NASA said in a statement on Monday.<\/p>\n
ATLAS pulses beams of laser light to the ground and then records how long it takes each photon to return.<\/p>\n
This time, when combined with the speed of light, tells researchers how far the laser light travelled.<\/p>\n
This flight distance, combined with the knowledge of exactly where the satellite is in space, tells researchers the height of the Earth\u2019s surface below.<\/p>\n
The stopwatch that measures flight time starts with each pulse of ATLAS\u2019s laser. As billions of photons stream down to Earth, a few are directed to a start pulse detector that triggers the timer, said Phil Luers, Deputy Instrument System Engineer with the ATLAS instrument.<\/p>\n
IANS<\/strong><\/p>\n Picture source: Alamy Image<\/strong><\/em><\/p>\n Image used for illustrative purposes<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":" NASA engineers have built a stopwatch that can measure accurately fraction of a billionth of a second.<\/p>\n","protected":false},"author":7,"featured_media":3631,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[29,31],"tags":[],"_links":{"self":[{"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/posts\/3630"}],"collection":[{"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/comments?post=3630"}],"version-history":[{"count":1,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/posts\/3630\/revisions"}],"predecessor-version":[{"id":3632,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/posts\/3630\/revisions\/3632"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/media\/3631"}],"wp:attachment":[{"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/media?parent=3630"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/categories?post=3630"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kt10.khaleejtimes.ae\/index.php\/wp-json\/wp\/v2\/tags?post=3630"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}