A Hands-On Tutorial on the Underwater Acoustic Channel Library

About This Tutorial

Reproducible evaluation of underwater acoustic receivers requires the ability to drive any candidate signal through a realistic channel and a realistic noise field, with full control over the experimental conditions. Most researchers solve this problem in private, with code and channel files that never leave the originating laboratory.

The Underwater Acoustic Channel Library, available at github.com/uwa-channels, removes this barrier. It provides eight measured channels from sites including the North Atlantic, Singapore, Hawaii, Norway, Japan, the Mariana Trench, and the Pacific, spanning transmission ranges from tens of meters to thousands of kilometers and center frequencies from 75 Hz to 25 kHz.

The companion MATLAB and Python toolboxes implement three core operations: replay (pass any signal through a measured channel), noisegen (generate realistic ocean noise), and unpack (reconstruct the full time-varying impulse response from the compressed storage format).

This tutorial will lead you through the process of integrating the toolbox into your own evaluation pipeline. You will leave with a working pipeline on your own laptop, replaying your own signals through several measured channels, with realistic noise added, and with a clear mental model of the underlying representations and assumptions.

Who Should Attend

Graduate students, postdoctoral researchers, early-career faculty, and practicing engineers working on underwater acoustic communications, signal processing, channel modeling, or machine learning for ocean signals. The tutorial is also suitable for newcomers from adjacent fields (terrestrial wireless, geophysics, machine learning) who want to access measured underwater data without first running their own sea trials.

Prerequisites

• Basic digital communications concepts (passband/baseband representations, multipath channels, equalization at a textbook level).
• Comfort with MATLAB or Python at the level of writing and debugging short scripts.
• No prior experience with the Library is assumed.

Learning Objectives

By the end of the tutorial, you will be able to:

• Navigate the Library's documentation site, download channels from Zenodo, and locate the appropriate toolbox and example scripts.
• Read and interpret the compressed channel file format, including the impulse-response tensor and the phase/delay-phase trajectory.
• Replay a passband signal of your own design through a measured channel and recover the received waveform at each receive element.
• Generate ocean noise consistent with measured statistics, including pink Gaussian spectra, spatial correlation across array elements, and impulsive heavy-tailed components.
• Unpack the compressed channel representation into a full time-varying impulse response and visualize its delay-Doppler structure.
• Locate and use the estimate repository to extract a channel from your own at-sea recordings.

Instructors

Schedule

Half-day single-track event (4 hours). Please bring your laptop with the software pre-installed (see Setup Guide).

Time	Session
08:30 – 09:00	Introduction Overview of the channel estimation methodology underlying the Library.
09:00 – 09:20	Module 1 — The Library at a Glance Overview of the eight hosted channels, their geographic and parametric coverage, and criteria for choosing a channel. Walkthrough of the documentation website, the Zenodo record, and the GitHub organization layout (matlab, python, estimate).
09:20 – 10:00	Module 2 — Replay Load a channel file, inspect its contents, generate a BPSK probe signal, call replay to drive it through the channel, and plot the received waveform, cross-correlation, and spectrum. Hands-on exercise with a channel and probe of your choosing.
10:00 – 10:20	Coffee Break ☕
10:20 – 11:00	Module 3 — Ocean Noise Call noisegen in three configurations: pink Gaussian (17 dB/decade slope), spatially correlated Gaussian across a multi-element array, and impulsive symmetric alpha-stable. Each followed by diagnostic exercises.
11:00 – 11:40	Module 4 — Unpack & Visualize Use unpack to reconstruct the full time-varying impulse response, visualize its evolution as a delay-time waterfall, and identify physical structures (direct path, surface/bottom bounces, Doppler-induced delay drift).
11:40 – 12:20	Module 5 — The estimate Repository Walkthrough of the companion repository: estimator pipeline, probe signals and constraints, visualization scripts. Attendees with at-sea recordings can attempt a first estimation pass.
12:20 – 12:30	Wrap-Up Contribution workflow for submitting newly estimated channels, overview of the GitHub discussion forum, and Q&A.

Materials

All materials will be available here before and after the tutorial. Template scripts are provided in both MATLAB and Python.

Pre-Tutorial Setup Guide

Please complete the following steps before arriving at the tutorial so that the in-room network is not a bottleneck. A detailed setup guide will be emailed to registered attendees two weeks before the event.

Option A: Python

1. Install Python 3.9 or later (python.org or via Anaconda/Miniconda).
2. Install the toolbox (includes all dependencies):

   pip install uwa-channels

3. Download two representative channel files from Zenodo (specific files will be announced).
4. Verify your setup by running an example script (see the Python toolbox repository for details).

Option B: MATLAB

1. Install MATLAB (R2021a or later) with the Signal Processing Toolbox.
2. Clone or download the MATLAB toolbox:

   git clone https://github.com/uwa-channels/matlab.git

3. Download two representative channel files from Zenodo (specific files will be announced).
4. Open MATLAB, add the toolbox folder to your path, and run example_replay.