Integrated Acoustics System The integrated acoustic system (IAS) is a cabled acoustic communication and positioning system that can be used to develop the next generation of observatory capabilities. IAS Infrastructure The IAS is comprised of five acoustic satellites. Each satellite is individually cabled to the acoustic control module (ACM). The satellites are equiped with a transducer that is capable of transmitting and recieving arbitrary acoustic signals between 5 and 80kHz. The ACM provides the satellites with timing signals and processes any signals from them.

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IAS Positioning System

In its initial configuration, the IAS will provide a highly reliable positioning for vehicles and instruments in the OTTB test range. Each object will be fit with a pinger, and the towers will track the location of the pinger through multilateration.

The IAS will be able to provide positioning information with a static accuracy of ±10cm. This will allow the IAS system to be used to monitor vehicle operations in the test range and validate navigation data.

The information from the IAS will be displayed with the OTTB's dynamic user interface. This interface will be software that runs on a clients computer and gives them access to all of the data available at the shore station, including underwater video.

The tracking page, shown above, has a 3D virtual representation of the underwater terrain. This gives users a 3D visual represntation of where all of the vehicles are with respect to one another. The software allows the user to zoom in and fly through the scene, allowing them to assess the location of their vehicle with respect to other objects in the test range.

The ability to know precisely where an underwater vehicle is, in real time, takes the risk out of many types of underwater vehicle research. Without this data, many researchers send their autonomous underwater vehicles (AUVs) into the depths of the ocean, cross their fingers, and hope that the mission will succeed and the vehicle will come back. The contact that they have with the vehicle while it is underwater is extremely limited, if there is any contact at all. This type of mission monitoring is not condusive to research involving AUVs operating in close proximety to other objects.

However, with the OTTB real-time monitoring system, an AUV operator can stop a test if a vehicle isn't behaving correctly. This will enable AUVs to operate safely in close proximety to existing fixed infrastructure, or allow mutliple vehicles to interact with each other; all without the risk of losing a vehicle.

IAS Communications Research

The IAS has been designed as a research platform. In order to keep developing new innovative ways to work on fixed subsea stations like observatories, new communication strategies which push the state-of-the-art will have to be developed. The OTL is always looking for researchers that would like to test their algorithms on this system.