Simulation of UUV environmental sampling in modeled ocean frontal zones

Abstract

Strategies are investigated for a simulated unmanned underwater vehicle (UUV) conducting environmental sampling missions in ocean frontal zones. The combination of environmental, vehicle, and navigation models enables the use of the simulator to investigate sampling and mapping choices. Initially, ocean frontal zones are simply modeled to characterize aspects of a deep ocean front similar to the Gulf Stream North Wall, and to simulate cross-frontal aspects of a shallow water front. The vehicle simulation is based on a nonlinear six degree of freedom model that allows for the effects of buoyancy and ocean currents to be incorporated. Forces on the vehicle are modeled as modified Taylor series expansions of the state of the vehicle. Two typical missions for UUV-based sampling are considered: cross-frontal density and downstream velocity structure for the deep ocean front, and cross-frontal cross-stream and vertical velocity structure for the shallow water front. These results provide a baseline for including more realistic sensor, navigation, and dynamics modeling.