Show simple item record

dc.contributor.authorThurnherr, Andreas M.  Concept link
dc.contributor.authorGoszczko, Ilona  Concept link
dc.contributor.authorBahr, Frank B.  Concept link
dc.date.accessioned2017-09-12T18:20:32Z
dc.date.available2017-09-12T18:20:32Z
dc.date.issued2017-08-11
dc.identifier.citationJournal of Atmospheric and Oceanic Technology 34 (2017): 1713-1721en_US
dc.identifier.urihttps://hdl.handle.net/1912/9223
dc.descriptionAuthor Posting. © American Meteorological Society, 2017. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 34 (2017): 1713-1721, doi:10.1175/JTECH-D-16-0258.1.en_US
dc.description.abstractData collected with acoustic Doppler current profilers installed on CTD rosettes and lowered through the water column [lowered ADCP (LADCP) systems] are routinely used to derive full-depth profiles of ocean velocity. In addition to the uncertainties arising from random noise in the along-beam velocity measurements, LADCP-derived velocities are commonly contaminated by bias errors due to imperfectly measured instrument attitude (heading, pitch, and roll). Of particular concern are the heading measurements, because it is not usually feasible to calibrate the internal ADCP compasses with the instruments installed on a CTD rosette, away from the magnetic disturbances of the ship. Heading data from dual-headed LADCP systems, which consist of upward- and downward-pointing ADCPs installed on the same rosette, commonly indicate heading-dependent compass errors with amplitudes exceeding 10°. In an attempt to reduce LADCP velocity errors, several dozen profiles of simultaneous LADCP and magnetometer/accelerometer data were collected in the Gulf of Mexico. Agreement between the LADCP profiles and simultaneous shipboard velocity measurements improves significantly when the former are processed with external attitude measurements. Another set of LADCP profiles with external attitude data was collected in a region of the Arctic Ocean where the horizontal geomagnetic field is too weak for the ADCP compasses to work reliably. Good agreement between shipboard velocity measurements and Arctic LADCP profiles collected at magnetic dip angles exceeding and processed with external attitude measurements indicate that high-quality velocity profiles can be obtained close to the magnetic poles.en_US
dc.description.sponsorshipPart of this research was made possible by a grant from the Gulf of Mexico Research Initiative to support the Ecosystem Impacts of Oil and Gas Inputs to the Gulf (ECOGIG-2) research consortium. Funding for acquisition of the 2015 Arctic data was provided by NSF (1203473 and 1249133) and NOAA (NA15OAR4310155) under the NABOS-II program.en_US
dc.language.isoen_USen_US
dc.publisherAmerican Meteorological Societyen_US
dc.relation.urihttps://doi.org/10.1175/JTECH-D-16-0258.1
dc.subjectOceanen_US
dc.subjectArcticen_US
dc.subjectAlgorithmsen_US
dc.subjectIn situ oceanic observationsen_US
dc.subjectMeasurementsen_US
dc.subjectProfilers, oceanicen_US
dc.titleImproving LADCP velocity with external heading, pitch, and rollen_US
dc.typeArticleen_US
dc.identifier.doi10.1175/JTECH-D-16-0258.1


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record