Blue Pebble

Blue Pebble is a research-oriented simulation framework for underwater acoustic sensing, built as a plugin for Stone Soup. It currently focuses on passive sonar: acoustic propagation modelling, beamforming, detection and multi-target tracking.

Installation

pip install blue-pebble

The package installs as blue-pebble and imports as bluepebble.

Getting Started

Start with the Getting Started tutorial, which simulates a towed array and beamforms, detects and tracks a single target. The documentation also has further tutorials, worked examples and the API reference.

Features

• Towed-array kinematics for the ownship, targets and array elements
• Acoustic propagation, from analytical spreading laws to ray tracing with rtrs
• Environments built from analytical profiles or measured bathymetry and sound-speed data
• Source and noise synthesis, including biological, anthropogenic and ownship noise
• Delay-and-sum and MVDR (Minimum Variance Distortionless Response) beamforming
• CFAR (Constant False Alarm Rate) detection, calibrated from noise or with a fixed threshold
• Detections that feed straight into Stone Soup trackers

Contributing

See CONTRIBUTING.md for the development setup and workflow, and the roadmap for planned extensions.

Citation

If you use Blue Pebble in academic work, please cite the associated conference paper and the software release (via DOI when available).

@inproceedings{wakefield2026sonar,
  title={A Sonar Signal Processing Plugin for Stone Soup},
  author={Wakefield, Joshua J and Boulton, Finley and Colquitt, Daniel J. and Ralph, Jason F. and Williams, Duncan P.},
  booktitle={2026 29th International Conference on Information Fusion (FUSION)},
  pages={1--8},
  year={2026},
  organization={IEEE}
}

Licence

Blue Pebble is released under the MIT licence; see LICENSE and NOTICE.md. Its ray-tracing dependency, rtrs, is also MIT-licensed and installs automatically. The package includes no external data, so users are responsible for complying with the licences of any data they use with it.