My research interests are in seismo-acoustic propagation, with specific application to the study of marine gas hydrates, and development and application of acoustic inverse methods for estimation of geophysical properties of the ocean bottom and for source localization.

• source localization with a vertical array in a range dependent shallow water  environment. This project makes use of the complex bathymetry of the continental  slope to resolve target bearing using a vertical array. (with M. Taileffer, Proceedings of 16 International Congress on Acoustics and 135th meeting of the Acoustical Society of America, pp 1771-2, June, 1998.)
• range/depth errors in matched field source localization. A systematic analysis  of 'mirages' in source position and their relationship to mismatch in the waveguide  environmental properties. (with Ron Kessel)
• inversion of head wave data from a vertical array for estimation of geoacoustic  properteis of the bottom (with html O. Godin and M. Laidlaw, Proceedings of 16  International Congress on Acoustics and 135th meeting of the Acoustical Society  of America, pp 2435-6, June, 1998. )
• matched field inversion of geoacosutic properties in a range dependent  environment. This project uses PE replica fields and a downhill simplex search  algorithm to estimate source position and waveguide properties. (with M. Musil)

• geoacoustic inversion using the freeze bath method. A new approach for estimating  geoacoustic properties by sampling the a posteriori distribution function (with L. Jaschke)
• geoacoustic matched field tomography using light bulb sound sources. An experiment  with three vertical arrays and broadband light bulb sources to estimate geoacoustic  properties over an area. (IEEE Oceans 97 Proceedings, pp763-768, October, 1997.)

• new experiments with high resolution deep towed multichannel seismic arrays to determine  the detailed velocity structure at the BSR. (with D. Hannay)

• a benchmark workshop to compare geoacoustic inversion methods. A set of test  data were generated and validated at UVic for use in the workshop. (Tolstoy, A.,  Chapman, N.R. and Brooke, G., Workshop97: Benchmarking for geoacoustic inversion in  shallow water, accepted in J. Comp. Acoustics, 1998.)

1. Chapman, N.R., Ozard, K.S. and Yeremy, M.L., Error bounds in matched field inversion for geoacoustic properties, accepted in J. Comp. Acoustics, 1998.

2. Elisseef, P., Schmidt, H., Johnson, M., and Chapman, N.R, Acoustic current tomography of a coastal front in Haro Strait, submitted to J. Acoust. Soc. Am., 1997.

3. Chapman, N.R and Hannay, D.E., Broadband matched field inversion for estimation of geoacoustic properties, in Shallow Water Acoustics, R. Zhang and J. Zhou editors, pp 145-150, China Ocean Press, 1997.

4. Pignot, P and Chapman, N.R., Tomographic inversion of geoacoustic properties in a range dependent shallow water environment, submitted to J. Acoust. Soc. Am., August, 1998.

5. Musil, M, Chapman, N.R. and Wilmut, M., Range dependent matched field  inversion of Swellex96 data using the downhill simplex algorithm, submitted to J. Acoust. Soc. Am., August, 1998.

6. Musil, M., Wilmut, M. and Chapman, N.R., A hybrid simplex genetic  algorithm for estimating geoacoustic properties using matched field inversion, submitted to IEEE J. Oceanic Eng., August, 1998.