Extracting Green s Functions Between Ships of Opportunity
Abstract
Methods for extracting Green~s functions between ships of opportunity will be developed for source localization with minimal enviro"nmental information and acoustic remote sensing in the form of moving ship tomography in shallow water. Passive noise correlation processing of distributed random noise has been successfully used to estimate the time-domain Green s function between two spatially separated receivers. However, the requirements for a long recording time, uniformity in the spatial distribution of sources as well as accurate synchronization made the approach impractical. An alternative way to measure the Green~s function between two points is to use secondary sources based on the time reversal mirror. By reversing the role of sources and receivers,we will explore the potential of using two separated ships along with a vertical receiver array to extract the Green~s functions between them. Our approach involves blind deconvolution to instantly extract the Green~s function from each of the ships, and then adopts the virtual receiver (VR) concept similar to the guide star in radio astronomy to estimate the Green~s functions between them. Further, using the waveguide invariant theory, a virtual horizontal array (guide sources) can be generated around the guide source at a closer range, whose every single element can turn into a VR for the distant target ship. The proof of concept will be verified by simulations and experimental data collected in shallow water.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 11, 2020
- Source ID
- N000142012213
Entities
People
- Hee-chun Song
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego