Accurate measurement of underwater radiated noise (URN) from ships in shallow water is critical for assessing compliance with marine environmental standards. However, shallow environments introduce significant distortion due to seabed and surface interactions, challenging the validity of conventional URN measurements. This study presents a methodology to calibrate and model shallow water acoustic ranges using in situ propagation loss (PL) measurements. Calibrated low-frequency acoustic projectors (43–1200 Hz) were deployed to emulate vessel noise sources and characterize transmission conditions. Measured PL was validated using physics-based models (KRAKEN/KRAKENC and BELLHOP), showing strong agreement in most frequency bands. Dynamic ship ranging trials were then performed, enabling transformation of shallow water measurements into deep-water equivalent source levels. A custom Python-based data tracking and visualization framework was developed to ensure precise positional analysis and efficient validation of acoustic trials. The resulting methodology provides a framework for evaluating and certifying candidate acoustic ranges in coastal areas, supporting broader access to URN assessments for maritime operators. These contributions advance the development of standardized shallow water ranging procedures and lay the groundwork for a future national standard. Ongoing work includes expansion to additional vessel types and environmental conditions.
Bassam et al. (Wed,) studied this question.