High-Resolution Acoustic Imaging Sonar
BMFL has a high-resolution acoustic imaging sonar available to examine environmental and ecological aspects of estuarine and coastal ecosystems for research and educational pursuits. Acoustic imaging sonars transmit sound pulses and convert the returning echoes into high-resolution digital images, much like a medical ultrasound sonogram. Thus, acoustic imaging sonars can “see” in zero visibility conditions, making it possible to track motile organisms and delineate underwater structures. Unhindered by the turbid waters of estuarine and coastal environments, acoustic imaging can operate at various temporal and spatial scales both day and night, with minimal or no disturbance to animals or habitats, and at much reduced labor intensity (e.g., 1 person). Together these attributes provide unmatched and powerful observational and experimental research opportunities.
Recent advancements in this technology have produced a second generation of acoustic imaging sonars. Unlike earlier sonars with low resolution (< 1.0 MHz), the ARIS Explorer 3000 has higher resolution (near 2X: 3.0 MHz vs. 1.8 MHz), a smaller housing, and greater computing and power efficiency. The ARIS 3000 imagery allows the user to identify and track targets as small as 3 mm in size at close range (5 m). Combined with the AR2 Rotator, operators can rotate the sonar a full 360" to completely survey the surrounding environment or gain a 3D-like perspective on a chosen target. Further, the rotator is programmable allowing for automated alternation between horizontal and vertical imaging modes. Imaging data collected during deployment can be analyzed with ARISFish and ARIScope software. More information is available on the sonar equipment and software from the manufacturer, Sound Metrics, Inc. (http://www.soundmetrics.com/).
Investigators and educators are encouraged to contact us with ideas for the use of high-resolution acoustic imaging sonar, or existing imaging data, to delve into questions focused on physical processes, organism-habitat relationships, animal behavior, and more in the estuarine and coastal habitats surrounding the North Inlet and Winyah Bay estuaries. Rates and policies for use of the sonar equipment can be found here.
Funding for the equipment came from the National Science Foundation’s Field Station and Marine Laboratory program. The intent of the grant was to enable BMFL to create new research and education opportunities for visiting and resident scientists and educators.