State Estimation for Tracking of Tagged Sharks with an AUV

Forney, Christina

doi:10.15368/theses.2011.219

Cited by 2 publications

(2 citation statements)

References 18 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Generally, AUVs follow a preprogrammed path, and there is currently no interface by which a pilot can turn it to emulate a manned vessel. This is changing with the advent of payload control systems that re-route an AUV in mission based on onboard computing and has been demonstrated for an AUV with a stereo-hydrophone for tracking an individual shark (Forney 2011). However, maneuvers meant to do this by both surface vessels or AUVs may be constrained by many considerations, including competing or complementary mission goals (such as hydrographic or side-scan sonar survey that require straight path segments) or when many tagged animals are being mapped synoptically and no single animal is prioritized.…”

Section: Discussionmentioning

confidence: 99%

Sound pressure level weighting of the center of activity method to approximate sequential fish positions from acoustic telemetry

Grothues

Davis²

2013

Can. J. Fish. Aquat. Sci.

View full text Add to dashboard Cite

Proximity of acoustically tagged fish to a hydrophone correlates with detection probability, thus allowing fish center of activity (CA) estimation as weighted averages of hydrophones' positions over fixed listening intervals. Alternately, weighting by the detection sound pressure levels (SPL) would require only a single detection from each hydrophone. We tested SPLweighted averaging performance relative to an independent and highly accurate positioning method, trilateration, for tagged fish. Positions calculated using SPL were similar to those using CA in the shape and sequence of the paths relative to the trilateration standard. Neither up-nor down-weighting transforms of SPL significantly affected solution error (209 m average, range 192-215 m) and did not differ significantly in error or shape from CA (194 m) over seven fish (1.9 million detections) even at the shortest of five tested averaging intervals (150, 300, 600, 1200, 2400 s). The method increased the stability of position estimates when a single moving receiver was used to create a synthetic array. Potentially, useful solutions can be calculated for tags outside array perimeters by extrapolating regressions to known source SPL.Résumé : Il existe une corrélation entre la proximité d'un poisson portant une balise acoustique par rapport à un hydrophone et la probabilité de détection, ce qui permet l'estimation de centres d'activité (CA) de poissons par le calcul des moyennes pondérées des positions d'hydrophones pendant des périodes d'écoute données. Une autre approche, la pondération en fonction des niveaux de pression acoustique (SPL) associés à la détection, ne nécessiterait qu'une seule détection par hydrophone. Nous avons évalué la performance de la méthode de pondération en fonction des SPL par rapport à une méthode de positionnement indépendante d'une grande exactitude, la trilatération, pour des poissons marqués. Par rapport aux positions de référence obtenues par trilatération, les positions basées sur les SPL étaient semblables aux estimations de CA en ce qui concerne la forme et la séquence des déplacements. La transformation par surpondération ou sous-pondération des SPL n'avait aucun effet significatif sur l'erreur de solution (moyenne 209 m, fourchette 192-215 m) et produisait des estimations dont l'erreur et la forme n'étaient pas significativement différentes des estimations de CA (194 m) pour sept poissons (1,9 million de détections) et ce, même pour le plus court des cinq intervalles de temps modélisés (150, 300, 600, 1200, 2400 s). La méthode accroît la stabilité des estimations de position quand un seul récepteur mobile est utilisé pour créer un réseau synthétique. Des solutions utiles peuvent potentiellement être calculées pour des balises se trouvant à l'extérieur du périmètre de tels réseaux en extrapolant les régressions jusqu'à des SPL de sources connues.

show abstract

Section: Discussionmentioning

confidence: 99%

Sound pressure level weighting of the center of activity method to approximate sequential fish positions from acoustic telemetry

Grothues

Davis²

2013

Can. J. Fish. Aquat. Sci.

View full text Add to dashboard Cite

show abstract

“…The particle filter algorithm was not developed in this thesis. This part has been done by another member of the shark tracking team[12]. The controller code sends the proper fin angle and motor speed to the main processor allowing the AUV to track the shark at the correct distance and position.…”

mentioning

confidence: 99%

Autonomous Tracking and Following of Sharks With an Autonomous Underwater Vehicle

Manii¹

View full text Add to dashboard Cite

AUTONOMOUS TRACKING AND FOLLOWING OF SHARKS WITH AN AUTONOMOUS UNDERWATER VEHICLE Esfandiar Manii This thesis presents the integration of an acoustic tracking system within an autonomous underwater AUV (AUV) to enable real-time tracking of sharks tagged with artificial acoustic sources. The tracking system consists of two hydrophones and a receiver unit that outputs a measurement of the relative angle to the tagged shark. Since only two hydrophones are used, the sign of the relative angle measurement is unknown. To overcome this ambiguity, a particle filter algorithm was developed to estimate the position of the acoustic source. When combined with an active control system that drives vehicle to obtain different orientations with respect to the acoustic source, real-time autonomous localization, tracking, and following of a tagged shark is shown to be possible. Four types of ocean experiments were used to validate the system including: 1) AUV tracking of a stationary tag, 2) AUV tracking of a tagged kayak, 3) AUV tracking of a tagged AUV, and 4) AUV tracking of a tagged shark. These experiments were analyzed with respect to the localization error, associated error variance, and distance between the AUV and the tag. The final shark tracking experiments took place in SeaPlane Lagoon, Los Angeles, CA, where the AUV was able to autonomously track and follow a tagged Leopard Shark for several hours.

show abstract

State Estimation for Tracking of Tagged Sharks with an AUV

Cited by 2 publications

References 18 publications

Sound pressure level weighting of the center of activity method to approximate sequential fish positions from acoustic telemetry

Sound pressure level weighting of the center of activity method to approximate sequential fish positions from acoustic telemetry

Autonomous Tracking and Following of Sharks With an Autonomous Underwater Vehicle

Contact Info

Product

Resources

About