Geoff Mullins

Geoff Mullins

Expertise: Underwater Acoustics
Affiliation: Simon Fraser University, Engineering Science, Underwater Research Laboratory
Certification/Education:
B.ASC Engineering Physics – Queen’s University, Kingston , Ontario , Canada
M.ASC Engineering Physics – University of British Columbia , Vancouver , British Columbia , Canada
PHD (on-going) – Simon Fraser University , Burnaby , British Columbia , Canada

From 2001 to 2003, I worked on High Temperature Superconductivity at the University of British Columbia . I then entered the School of Engineering Science at Simon Fraser University , where I switched research fields to underwater acoustics, specifically multi-angle swath bathymetry (MASB) sonar.

I have been involved with the Pavilion Lake research project for three years, having surveyed the lake with conventional sidescan sonar, and more recently with MASB sonar. This sonar is a research prototype that our lab has designed and built to operate at frequencies up to 300kHz. One component of my research involves a performance analysis of this type of instrument.

The purpose of my research is to characterize the bottom of Pavilion Lake using acoustic backscatter. I am producing a bathymetric map of Pavilion Lake using data collected with MASB sonar. An acoustic Bottom Backscatter Strength (BBS) map of Pavilion Lake is also being generated. By examining the physical phenomena that govern the behavior of acoustic signals returning from the lake bottom, a characterization will be made of the lake bottom composition. Through techniques such as scuba diving and using a drop camera I have been able to visually confirm the sonar data.

Acoustic remote sensing is a useful tool as it is both a non-intrusive probe and can collect information at further ranges than optical techniques in most underwater environments. Preliminary measurements at Pavilion Lake have revealed isolated microbialite structures in deeper water than previous investigations. These deep water structures are located in water that is deeper than can be accessed through the use of conventional scuba diving, and are sparsely distributed. In such circumstances a method such as sonar surveying is ideal.

Links

Underwater Research Laboratory