Underwater Channel Model For The Tropical Waters.

The tropical waters are extremely unique, given the random fluctuations in the medium parameters and the complex impact on the underwater signals while propagating through these channels. The applications must be able to assess the precise modification of the underwater medium to be able to either mitigate or neutralize the impact. The Modelling & Simulation (M&S), efforts with field validation is the most critical aspect of the entire assessment process. The real-time M&S is the key and needs to be realized appropriately.

The researchers and industry users need the access to such a high technology tools, so that they can use it to manage the impact of the underwater medium. The users at times are limited in their ability to really appreciate the finer details of the tool and not able to modify the default value based on the changing medium conditions. Thus, developing a user friendly underwater channel model that is representative of the diverse underwater condition particularly in the tropical waters. The channel model will be like a black box, where the user needs to only feed the specific inputs specific to the real-time underwater parameters and also the application specific inputs. The tool will provide detailed qualitative and quantitative appreciation of the underwater channel impact.

The generic underwater channel models available in the open source are diverse, starting with ray theory based and more recently the wave theory based models. The former is simple and easy to visualize, however does suffer from inaccuracy and its inability of map multiple boundary conditions that are very critical for the modelling effort. The wave based models are far more accurate and are able to map the boundary conditions very well. However, these are extremely computationally intensive and demand significant inputs on the underwater boundary conditions and other medium parameters. The real-time output, also requires significant computational infrastructure and optimization for the algorithms. In today’s age of data science and Artificial Intelligence (AI) based data analytics, the wave theory based underwater channel are slowly becoming the de facto standard.

This project presents a detailed digital tool for mapping the underwater channel in the tropical waters. The inputs are taken from online sources (ETOPO) in real-time and the tool is able to deliver the outputs in near real-time for varied applications. The project has shortlisted the Parabolic Equation (PE), wave theory based model with substantial customization to make it real-time and enhance its accuracy. The model also caters to marine and freshwater system across multiple geographies. The project has undergone multiple iterations with participation of multi-disciplinary researchers over the last couple of years. The researchers have worked on three distinct aspects, starting from the availability of the data, and how to manage the gaps in data availability. The second is the algorithms and the computational infrastructure and knowhow. The optimization of the algorithms at multiple levels is the key to making it real-time. The last but not the least is the display or other means to make the actionable inputs available to the user in a form and format that is user friendly.