bellhopcxx / bellhopcuda

C++/CUDA port of BELLHOP/BELLHOP3D underwater acoustics simulator.

Impressum

Copyright (C) 2021-2026 The Regents of the University of California
Marine Physical Lab at Scripps Oceanography, c/o Jules Jaffe, jjaffe@ucsd.edu
Based on BELLHOP / BELLHOP3D, which is Copyright (C) 1983-2022 Michael B. Porter

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.

Breaking changes

While we strive to maintain backward compatibility with bellhopcxx / bellhopcuda version, some breaking changes have been introduced in version 1.5.0. Most notably, the binarry output data files, .shd and .arr, have been updated to match the current behavior of BELLHOP / BELLHOP3D 2024 update to the Acoustics Toolbox.

CMake has also been updated to version 3.27 minimum to support automated recognition of CUDA enabled systems. You may need to update your CMake installation.

Updated Features

• Provence ocean SSP model support.
• Background calculation in library mode.
• Combined Eigenray and arrivals run mode using V option.
• Several bug fixes and performance improvements.
• More example programs showing library usage.

Current Status

There is an ongoing issue with 3D runs in complex environments falsely identifying rays as interacting with receivers, even at very large distances. This can lead to errors in all run types except ray runs. We are actively working to resolve this issue. This issue affects both CPU multithreaded and CUDA modes. It is also present in the original BELLHOP / BELLHOP3D code.

Compilation

We use a CMake-based build system. Please see the doc/compilation.md document for detailed instructions.

Speed

• The speedup in multithreaded mode roughly scales with the number of logical CPU cores.
• The speedup in CUDA mode
  • Consumer-grade GPU (e.g. NVIDIA GeForce RTX 3060): typically about 10x-50x speedup over BELLHOP / BELLHOP3D for large runs with few receivers.
  • Server-grade GPU (e.g. NVIDIA A100): typically about 20x-100x speedup and less sensitive to receivers layout.

Detailed performance results are available in the doc/performance.md document.

Accuracy

The accuracy characteristics of bellhopcxx / bellhopcuda are discussed in the doc/accuracy.md document.

Miscellaneous

Comments

Unattributed comments in all translated code are copied directly from the original BELLHOP / BELLHOP3D and/or Acoustics Toolbox code, mostly by Dr. Michael B. Porter. Unattributed comments in new code are by the Marine Physical Lab team, mostly Louis Pisha. It should usually be easy to distinguish the comment author from the style.