Research
Introduction to research in the Underwater Acoustics area.
Underwater Acoustics research
- Technical Guides on Sound in Air, Ultrasonics and Underwater Acoustics.
- The increasing level of man-made sound in the ocean (whether deliberately generated or not) has led to concern over marine noise pollution.
- Research into a new optically-based primary standard for the calibration of underwater hydrophones for direct and absolute calibration of hydrophones, directly related to the unit of acoustic sound pressure.
- Data describing the variation in performance of commercially available hydrophones with temperature and depth have until now been difficult to obtain and are not readily available from hydrophone manufacturers.
- This shows performance data for a number of commercially available hydrophones that have been characterised at various simulated ocean conditions.
- NPL's Acoustics Pressure Vessel can be used to simulate ocean conditions and support various measurements.
- NPL is currently working on the development of techniques to predict the far-field response from measurements made in the acoustic near-field.
- Details on various underwater acoustics standards, including free-field hydrophone at different frequency ranges.