{"id":116531,"date":"2020-12-01T20:22:58","date_gmt":"2020-12-02T04:22:58","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2020\/12\/stanford-engineers-invent-a-sonar-device-that-works-outside-the-water"},"modified":"2020-12-01T20:22:58","modified_gmt":"2020-12-02T04:22:58","slug":"stanford-engineers-invent-a-sonar-device-that-works-outside-the-water","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2020\/12\/stanford-engineers-invent-a-sonar-device-that-works-outside-the-water","title":{"rendered":"Stanford engineers invent a sonar device that works outside the water"},"content":{"rendered":"<p><\/p>\n<p><iframe style=\"display: block; margin: 0 auto; width: 100%; aspect-ratio: 4\/3; object-fit: contain;\" src=\"https:\/\/www.youtube.com\/embed\/2YyAnxQkeuk?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; encrypted-media; gyroscope;\n   picture-in-picture\" allowfullscreen><\/iframe><\/p>\n<p>Radar and LiDAR have been incredibly quick and effective tools for mapping and surveying the Earth\u2019s surface from aircraft and satellites, but while they can deliver accurate readings through cloud and even forest canopy cover, they can\u2019t tell you what\u2019s below the surface of the sea. Seawater absorbs far too much of the signal.<\/p>\n<p>Sonar remains the most effective way to map out the sea floor \u2013 but the vast majority of the oceans that form 70 percent of the Earth\u2019s surface remain unmapped, because sonic waves have hitherto only been able to be sent out from underwater. Sound waves sent from air into water lose more than 99.9 percent of their energy in the translation; it\u2019s why the outside world goes so wonderfully silent when you dive down to the bottom of the pool. The meagre remaining 0.1 percent of the energy does create a sonar signal, but that loses a further 99.9 percent of its energy upon coming back up from the water into the air.<\/p>\n<p>Sonar is commonly used for submarine detection, among other things, by military forces the world over, chiefly using devices on the undersides of ships. But the closest things thus far to an airborne sonar system are \u201cdippers\u201d like <a class=\"\" href=\"https:\/\/www.thalesgroup.com\/en\/worldwide\/defence\/naval-forces\/underwater-warfare\/anti-submarine-warfare-airborne-systems\" target=\"_blank\">Thales\u2019 FLASH system<\/a>; low-frequency, wide-band sonar systems that dangle from cables out the bottom of helicopters and dip into the sea below like noisy teabags. These methods are slow, expensive, and no good at covering large areas.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Radar and LiDAR have been incredibly quick and effective tools for mapping and surveying the Earth\u2019s surface from aircraft and satellites, but while they can deliver accurate readings through cloud and even forest canopy cover, they can\u2019t tell you what\u2019s below the surface of the sea. Seawater absorbs far too much of the signal. Sonar [\u2026]<\/p>\n","protected":false},"author":542,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1497,1965,9,2028],"tags":[],"class_list":["post-116531","post","type-post","status-publish","format-standard","hentry","category-energy","category-mapping","category-military","category-satellites"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/116531","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/542"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=116531"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/116531\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=116531"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=116531"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=116531"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}