Buried Underwater Mine Hunting Project: Status and Plan

We will describe our effort on Buried Underwater Mine
Hunting Project supported by US Navy.
Underwater mines are significant threat to both Navy and commercial ships.
Many of them are buried shallowly under the ocean floor.
To detect such targets, Navy has been examining the use of
the Synthetic Aperture Sonar (SAS) system for wide range survey and
the Buried Object Scanning Sonar (BOSS) system for the detailed analysis,
both equipped on Unmanned Underwater Vehicle (UUV).
Our objective is to examine whether we can discriminate mines from
non-mine objects, and if so, whether we can classify the type of the mines
using the data acquired by these sonars.
We will first review the SAS and BOSS systems, how images are formed from
the sonar data. The imaging algorithms are essentially the same as those
developed for seismic imaging/migration.
Then, we will report the current status of this project using the
experimental data measured in a pond.
Finally, we will report the current status of our analysis of
the near field data of a simpler experimental configuration in a pool
using “spark-gap” like underwater acoustic source and a hydrophone.
The phase information turns out to be important for classification,
which can be enhanced by amplitude-phase decomposition algorithms
such as the one based on Blaschke products.
This work is a collaboration with Hong Xiao, Bradley Marchand, and
Ernest Woei of UC Davis, and Quyen Huynh and his group at Naval Surface
Warfare Center, Panama City, FL.