Factors affecting detection efficiency of mobile telemetry Slocum gliders

Matthew J Oliver,Danielle E Haulsee,Josh Kohut,Megan A Cimino,Matthew W Breece,David Aragon,Dewayne A Fox

doi:10.1186/s40317-017-0129-8

Abstract

BackgroundAcoustic biotelemetry sensors have been fully integrated into a broad range of mobile autonomous platforms; however, estimates of detection efficiency in different environmental conditions are rare. Here, we examined the role of environmental and vehicle factors influencing detection range for two common acoustic receivers, the VEMCO mobile transceiver (VMT) and a VEMCO cabled receiver (VR2c) aboard a Teledyne Slocum glider. We used two gliders, one as a mobile transmitting glider and one as a mobile receiving glider during the fall in the mid-Atlantic coastal region.ResultsWe found distance between gliders, water depth, and wind speed were the most important factors influencing the detection efficiency of the VMT and the VR2c receivers. Vehicle attitude and orientation had minimal impacts on detection efficiency for both the VMT and VR2c receivers, suggesting that the flight characteristics of the Slocum glider do not inhibit the detection efficiency of these systems. The distance for 20% detection efficiency was approximately 0.4 and 0.6 km for the VMT and VR2c, respectively. The VR2c receivers had significantly lower detection efficiencies than the VMT receiver at distances <0.1 km, but higher detection efficiencies than the VMT at distances >0.1 km.ConclusionsSlocum gliders are effective biotelemetry assets that serve as sentinels along important animal migration corridors. These gliders can help elucidate the relationships between telemetered organisms and in situ habitat. Therefore, estimating the detection ranges of these common telemetry instruments provides an important metric for understanding the spatial scales appropriate for habitat selection inferences.

Highlights

Acoustic biotelemetry sensors have been fully integrated into a broad range of mobile autonomous platforms; estimates of detection efficiency in different environmental conditions are rare
While autonomous underwater vehicle (AUV) often measure environmental conditions that could impact listening conditions [6], moving platforms and dynamic environments create new range of testing challenges. One solution to this challenge is near-real-time triangulation of the acoustic signal using a combination synthetic aperture and known test tag locations [7]. Another solution is using a combination of stereo receivers and near-realtime particle filtering [8], and multiple AUVs to geolocate the acoustic tag on meter scales [9]
Data collected by the receiving (Fig. 3b) and transmitting (Fig. 3c) gliders show the erosion of the pycnocline and a general increase in density due to cooling over the study period

Summary

Introduction

Acoustic biotelemetry sensors have been fully integrated into a broad range of mobile autonomous platforms; estimates of detection efficiency in different environmental conditions are rare. While AUVs often measure environmental conditions that could impact listening conditions [6], moving platforms and dynamic environments create new range of testing challenges. One solution to this challenge is near-real-time triangulation of the acoustic signal using a combination synthetic aperture and known test tag locations [7]. Another solution is using a combination of stereo receivers and near-realtime particle filtering [8], and multiple AUVs to geolocate the acoustic tag on meter scales [9].

Methods

Results

Conclusion