|Passive vector geoacoustic inversion in coastal areas using a sequential unscented Kalman filter|
Candy, J.V.; Ren, Q.; Hermand, J.-P. (2013). Passive vector geoacoustic inversion in coastal areas using a sequential unscented Kalman filter, in: IEEE SYMPOL Conference Cochin, India October 23, 2013 through October 25, 2013. pp. 6 pp
In: (2013). IEEE SYMPOL Conference Cochin, India October 23, 2013 through October 25, 2013. IEEE: New York. , more
|Authors|| || Top |
- Candy, J.V.
- Ren, Q., more
- Hermand, J.-P., more
An unscented Kalman filter (UKF) for geoacoustic inversion using scalar and vector sound fields created by a passing ship is discussed in this paper. The continuous sound field emitted by a ship of opportunity is processed by the sequential filtering technique to estimate slowly changing environmental properties along the source range. The inversion problem is solved by the UKF with a random-walk parameter model, which is expected to perform well when dealing with highly nonlinear problems. Synthetic geoacoustic inversions are performed using multi-frequency pressure, vertical particle velocity and waveguide impedance (a ratio between pressure and vertical particle velocity) data for the geoacoustic model of a mud environment offshore at the mouth of the Amazon river in Brazil (CANOGA 12). For the preliminary tests, the sound source is composed of a flat spectrum. Numerical results demonstrate that the sequential filtering technique is capable of estimating the evolution of environmental properties along the source range. In practice, ship data have complex time-varying spectral characteristics that can greatly limit the accuracy of broadband or multi-frequency passive applications. Since the vertical waveguide impedance is independent of the source spectral level, it is preferred for environmental characterization by the sound field generated from a ship of opportunity. Because of this independence property, the vertical waveguide impedance is expected to yield a more reliable inversion than that of pressure or vertical particle velocity field.