Photoacoustic Airborne Sonar for Non-Contact Detection Under Water
Abstract
This project will investigate detecting targets under water using an airborne SONAR system. An intensity modulated laser will be used to create acoustic waves on the water surface using the photoacoustic effect. The generated acoustic waves will travel in all directions under water, reflecting from any targets that are present. The reflected acoustic waves will be collected by using highly sensitive capacitive micromachined ultrasonic detectors (CMUTs). Signal processing techniques will be used to locate the targets under water. We propose a hybrid system that uses both electromagnetic waves and acoustics. In particular, using the photoacoustic effect, acoustic waves can directly be generated at the air-water interface, following which they reflect off of underwater targets and are collected by airborneultrasound sensors. Because of the direct generation of ultrasound at the air-water interface, the proposed hybrid system has lesser signal loss than competing modalities. Instead of the 130dB round-trip loss that would be seen by a completely airborne SONAR system, our hybrid system would only have to account for a 65dB loss as the reflected signal from the target travels from water to air.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 25, 2019
- Source ID
- N000141912241
Entities
People
- Amin Arbabian
Organizations
- Office of Naval Research
- Stanford University
- United States Navy