Laser-acoustic detection of objects buried underwater - ONR White paper tracking # 20-000000213
Abstract
Approved for Public ReleaseAbstractNaval operations in littoral regions face dangers and delays from buried and hidden mines and improvised explosive devices (IEDs). Mines and IEDs may be buried in the sediment in shallow waters, on beaches or regions adjacent to the water, or inland in roadways or soils. Rapid, standoff, wide-area mine and IEDs detection capability is required to detect these explosive hazards, so that they can be avoided or cleared to allow safe passage of personnel, equipment, and supplies, and maintain operational tempo. An acoustic/seismic technology has been proven as a reliable method, having a high probability of detection and low false alarm rate. Keys to successful implementation of this technology include rapid, standoff methods for accurate ground vibration measurement over wide areas and the adaptation of this technology for mine detection in littoral areas. Recent research work at The University of Mississippi (UM) National Center for Physical Acoustics (NCPA) under ONR grant No.00014-12-1-0202 and ONR contract NOOO14-16-C-3038 has demonstrated that pulsed digital shearography is capable of detecting buried mines and IEDs by measuring their vibration signatures. NCPA has also demonstrated that pulsed shearography is capable of detection of objects buried in sediments underwater. While the results of using pulsed shearography for detection of underwater buried objects are very promising, there are challenges that needs to be investigated in order to make shearography based laser-acoustic detection technique a practical tool. One of the fundamental challenges is caused by the fact that optical phase of the probe laser light is modulated not only by vibration of the sediments surface to be measured but also by waves on the water surface caused by the vibration, and by variation of the index of refraction of water caused by acoustic waves in water. Therefore, more research is required in order to overcome these challenges and develop practical methods for laser-acoustic detection of objects buried in underwater sediments. The goal of this program is to investigate physical phenomena associated with laser -acoustic detection of objects buried underwater, and enhance laser-acoustic methods for detection of mines and IEDs buried in underwater sediments.This program is planned for three-year duration. The focus for the first year will be to design and build an experimental setup for investigation of laser-acoustic detection of objects buried underwater, and to investigate detection of a vibrating object buried underwater by sensing vibration of the water surface with an interferometric sensor, and vibration of water surface insonified with airborne sound. The efforts in the second year will focus on investigation of detection of a vibrating object buried underwater by sensing vibration of the bottom surface with an interferometric sensor located in the air, as well as in water. The tasks for the third year will focus on investigation of the performance of two detection scenarios: first, when both an acoustic excitation source and an interferometric sensor ae water surface, and the second, when both an acoustic excitation source and an interferometric sensor are positioned underwater.The team for the proposed work has extensive experience in the development and application of laser vibration sensors for acoustic detection of buried mines, including digital shearography, multiple beam laser Doppler vibrometry, and speckle-pattern interferometry.Based on the lessons learned during those efforts, the team is confident that the proposed work is well within its capabilities.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 06, 2021
- Source ID
- N000142112247
Entities
People
- Vyacheslav Aranchuk
Organizations
- Office of Naval Research
- United States Navy
- University of Mississippi