{"id":648,"date":"2019-05-29T17:12:48","date_gmt":"2019-05-29T21:12:48","guid":{"rendered":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/?page_id=648"},"modified":"2019-05-29T17:17:38","modified_gmt":"2019-05-29T21:17:38","slug":"marine-gravimetry","status":"publish","type":"page","link":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/research\/marine-gravimetry\/","title":{"rendered":"Marine Gravimetry"},"content":{"rendered":"\n\t

Marine Gravimetry<\/h1>\n\t

Marine gravity measurements allow scientists to better understand the Earth’s crust by providing quantitative constraints on the structure of the crust and, in combination with other co-registered data sets and forward models, improve our ability\u00a0to interpret the geological processes occurring within oceanic crust. \u00a0As an engineer and robotist, I pursue new methods for obtaining these measurements from underwater robots. \u00a0This work requires research in navigation, control, and sensing. \u00a0In addition, I support the collection of gravity data on research vessels throughout the world.<\/p>\n

AUV Gravimetry<\/h2>\n

While these measurements are routinely\u00a0obtained from surface vessels (including through an NSF funded sea-surface marine gravity program I run),\u00a0the resolution and spatially density is significantly improved when measurements are obtained from underwater\u00a0vehicles operating near the seafloor. Near seafloor measurements have been previously obtained with\u00a0piloted submarines and towed sleds; however, their high cost precludes routine acquisition of these measurements.\u00a0Furthermore, these vehicles lack the precision control and navigation necessary for minimizing vehicle\u00a0motion and for separating the accelerations of the vehicle from the gravity signals being measured. I have been\u00a0researching precision navigation methods that would enable AUVs to obtain measurements superior to those\u00a0previously obtained and at a lower cost. \u00a0Kinsey et al., 2013<\/a>\u00a0shows that nonlinear dynamic\u00a0model-based state estimators provide superior estimates of the vehicle\u2019s vertical accelerations than methods\u00a0used in previous underway submarine gravity surveys, thereby providing more precise measurements and allowing\u00a0us to detect smaller features in the shallow oceanic crust. Additional research has focused on new\u00a0trajectory planners for AUV gravity surveys that minimize AUV motion in order to obtain better gravity measurements (Izraelevitz\u00a02010<\/a>) and the investigation\u00a0of a\u00a0new class of smaller and less power consumptive gravimeters. This sensor research exploits a new type\u00a0of accelerometer that when combined with highly accurate attitude measurements from an INS eliminates the\u00a0electronics and leveling table required for traditional gravimeters. The first generation system was deployed\u00a0on the Sentry AUV in 2011 and served as the basis for a new, second-generation AUV gravimeter that is\u00a0currently being evaluated in the laboratory.<\/p>\n

Sea Surface Gravimetry<\/h2>\n

In addition to researching new methods for measuring gravity from AUVs, I also oversee the Potential Feld Pools (PFPE), an NSF funded facility that supports and maintains the U.S. academic community’s fleet of gravimeters. \u00a0These gravimeters are deployed on 10 ships that travel all over the world including the Arctic and Antarctic. \u00a0Read more about PFPE\u00a0here<\/a>.<\/p>\n\t\t\t\t\n\t\t\t\t\"Geophysical\n\t\t\t\t<\/a>\n\t\tGeophysical anomalies plotted by their comparative gravity anomaly and spatial wave-length. The \ncurves represent the sensing limits of satellite and surface vessel gravimeters with each sensor being capable of measuring features above and to the right of the sensor\u2019s limit curve. Features below and to the left of the surface vessel curve presently can not be routinely measured using existing gravimeter technology and motivate developing new sensors.\n","protected":false},"excerpt":{"rendered":"

Marine Gravimetry Marine gravity measurements allow scientists to better understand the Earth’s crust by providing quantitative constraints on the structure of the crust and, in combination with other co-registered data sets and forward models, improve our ability\u00a0to interpret the geological processes occurring within oceanic crust. \u00a0As an engineer and robotist, I pursue new methods for…<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":603,"menu_order":5,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/wp-json\/wp\/v2\/pages\/648"}],"collection":[{"href":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/wp-json\/wp\/v2\/comments?post=648"}],"version-history":[{"count":3,"href":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/wp-json\/wp\/v2\/pages\/648\/revisions"}],"predecessor-version":[{"id":653,"href":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/wp-json\/wp\/v2\/pages\/648\/revisions\/653"}],"up":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/wp-json\/wp\/v2\/pages\/603"}],"wp:attachment":[{"href":"https:\/\/www2.whoi.edu\/site\/jameskinsey\/wp-json\/wp\/v2\/media?parent=648"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}