Autonomous Vertical Profiler (AVP) for Profiling Coastal Waters

Profiler has a control system with a linearized plant and a proportional-plus-integral (PI) controller that automatically determines the thrust to the motor so as to trim the system to a user specified speed. By the use of gain scheduling techniques.

The profiler device is a controllable variable speed thruster-driven oceanographic profiler for coastal waters for measuring the vertical structure of chosen properties of the oceanic water column.

• Hands-free, slightly buoyant, thruster/motor-driven in situ robot profiler that requires no operator skill or deployment gear.
• Obtaining true profiles decoupled from ship motion induced perturbations : not being attached to the launching platform with a cable or rope ensures that ship or platform movement does not colour the vertical profiles.
• Repeatability from multiple profile data that provides adequate error statistics through the use of less expensive sensors, for profile shape variability
  Oceanographic sensors to measure vertical structure at high resolution (10 cm) in waters as shallow as 5 m and as deep as 200 m
• Ease of launching: It can be deployed easily by hand from a research ship, an inflatable craft, or a country trawler without any support of any specialized gear
  Autonomous operation and one man deployable, that saves time and reduces cost: AVP can be programmed to descend at variable speeds to a given depth set by the user
• Capability of hovering at any set depth so that time series of a feature can be studied in detail
• Building as much smartness in the software code to ensure safety and optimal use of energy on board. The use of RF and satellite modems is now widely available and this has been used to beam valuable data back to shore computer.
• The AVP saves power by using its motor only for descent dives but requires no power to ascend, as it is positively buoyant.
• AVP is not affected by density gradient in coastal waters, and works equally well in turbid and saline waters of the coast.
• This technology is useful for rapid profiling of shallow waters temperature, salinity, chlorophyll and dissolved oxygen. It is useful for time series monitoring of biological blooms. It is also a validation tool for Ocean Colour Satellites.