Skip to main content
Open Access Publications from the University of California

Acoustic navigation of a large aperture array.

  • Author(s): Sotirin, Barbara J
  • Hildebrand, John A
  • et al.

Acoustict ravelt ime measurementwse reu sedt o navigatet he elementso f a large-aperture(9 00 m) acoustica rray. Array navigations ystemp erformancew ase valuatedd uring a vertical deploymenitn the northeasPt acificf rom the ResearchP latformF LIP. A networko f bottommooreda coustictr ansponderws erei nterrogatedfr om FLIP and their 12-kHz repliesw ere detectedb y receiversa t 75-m intervalsa longt he array. A nonlinearl east-squareasl gorithm wasu sedt o estimateF LIP and array elementp ositionsfr om the travelt ime measurements. The FLIP positionsd erivedf rom this procedurea greedw ith positionso btainedf rom global positionings ystem( GPS) satelliten avigationt o within a 10-mr mse rror. Navigatedp ositions for FLIP were internallyc onsistenwt ith a 0.5-m meanr ms error and standardd eviationo f 1.1 m, and, for an array element,w ere consistentw ith a 2.8-m mean rms error and standard deviationo f 0.8 m. The resultingti mes erieso f arraya nd FLIP motionsw erea nalyzedw ith respecto wind, tidal, and internalw avef orcingf unctionsW. ind and tidal forcingh ad the greatesti nfluenceo n FLIP motion,w hereasa rray motionw asg overnedb y FLIP movement, tides,a nd higherf requencys ourcesL. ow-frequencya rray motion,w ith periodso n the ordero f hours,w asa resulto f FLIP towingt he array overa horizontalr angeo f 300 m in responsteo the wind and the semidiurnalt idal oscillationst;h e array remainedw ithin a 30-m horizontal range of FLIP's position. Higher frequency array motion had apparent internal wave and surface-couplecdo mponentsT. he array shapew asp rimarily straighta nd nearly vertical,t o within approximatelya 2ø t ilt, respondinga sa simplep endulumw ith smalld isplacements.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View