Robust estimation and aggregation of ocean internal wave parameters using Lagrangian drifters

Abstract

This paper considers a group of drogues whose objective is to estimate the physical parameters that determine the dynamics of ocean nonlinear internal waves. While underwater, individual drogues do not have access to absolute position information and only rely on inter-drogue measurements. Building on this data and the structure of the drogue dynamics under the flow induced by an internal wave, this paper improves in three different ways upon our previous strategy, termed PARAMETER DETERMINATION STRATEGY, which determines all wave parameters. The first is by showing that with sufficiently fast sampling, the extended algorithm determines the wave parameters. The second is by showing its applicability to situations where two internal waves are present simultaneously. With the extended algorithm, multiple estimates are calculated for each parameter. Thus, with the presence of noisy measurements, the third contribution is a method to aggregate parameter estimates to reduce the error. Simulations illustrate the algorithm performance under noisy measurements, the effect that the initial drogue locations has on robustness, and the effectiveness of parameter aggregation.