1 / 15

Preliminary Geoacoustic Inversion Results from SW06 Data

Preliminary Geoacoustic Inversion Results from SW06 Data. Ross Chapman. University of Victoria, BC, Canada. ONR Shallow Water Experiment 06 Workshop January, 30-31, 2007 San Diego, CA. Low Frequency Geoacoustics (Knorr: Aug 23 – Sept 06) Bill Hodgkiss, Peter Gerstoft, Chenfen Huang (MPL)

diamond
Télécharger la présentation

Preliminary Geoacoustic Inversion Results from SW06 Data

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Preliminary Geoacoustic Inversion Results from SW06 Data Ross Chapman University of Victoria, BC, Canada ONR Shallow Water Experiment 06 Workshop January, 30-31, 2007 San Diego, CA

  2. Low Frequency Geoacoustics (Knorr: Aug 23 – Sept 06) • Bill Hodgkiss, Peter Gerstoft, Chenfen Huang (MPL) • David Knobles et al (ARL) • Ross Chapman, Yongmin Jiang, (UVic) ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  3. Objectives: • Geoacoustic model for common site • Broad frequency band • Well surveyed range dependence • Data sets used (at VLA1): • Low frequency tonals for 3 ranges • along ‘DJ’ track • Chirps at fixed range • Approaches: • MFI for tonal signals • single layer geoacoustic model • Reflection coefficient inversion • of fixed range chirp data ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  4. Example of matched field inversion result – parameter uncertainty estimates at WP21 (~ 1km) ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  5. Example of data processing for reflectivity coefficient inversion – Fixed range high frequency chirps • Sea floor & subbottom reflection • at VLA1 site • Sound speed and attenuation • from 2000 ~ 4000 Hz • Sound speed ~ 1580 m/s ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  6. Preliminary low frequency geoacoustic model for ‘DJ’ track • sea floor sediment parameters over range dependent track • sediment sound speed: ~1600 m/s (50 – 900 Hz) • Some problems with the data: • MFI: no information in some tonal frequencies • Significant variation in signal level • Significant variation in SSP • Array geometry: hydrophone depths uncertain? • What other information do we need? • Chirp sonar track over DJ line; geoprobe data • Swell and wave direction & height • Source levels for LF and MF sound sources • ARL acoustic data from SWAMIs • Collaborations for geoacoustics: • Geoacoustic models for broad frequency band for • DJ track and Moray/VLA site • SWAMI site data ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  7. Collaborations for geoacoustics: • Geoacoustic models for broad frequency band for • DJ track and Moray/VLA site: • MPL (LF < 4500 Hz) and APL (2 – 20 kHz) • SWAMI site data: ARL • long and short range geoacoustic inversion at sandy site • expect less variation in SSP • LF and MF data (chirps) • Experimental benchmark data set for inversion methods? • Target a JASAEL collection of preliminary results (2007)? • Hurricane Ernesto Noise data: SWAMIs ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  8. Discussion Slides ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  9. Energy Function: • final energy of each frequency in optimization: 0.2338038 • 0.00363505 ( 53Hz) 0.21442491(103Hz) 0.56934798(203Hz) 0.40013963(253Hz) • 0.57140428 (303Hz) 0.37056041(403Hz) 0.35731304(503Hz) 0.66464043(703Hz) ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  10. WD=79.5, Rdvb = 8.2m WD=79.5m, Rdvb=11.8m WD=78.8, rdvb =8.2m, 8fres WD=78.8, rdvb =11.8m, 8fres ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  11. WD=78.8, rdvb =9.05m, 8fres WD=78.8, rdvb =8.55m, 8fres WD=78.8, rdvb =11.8m, wp21 ssp WD=78.8, rdvb =11.8m, wp22 ssp ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  12. WD=78.8, rdvb =11.8m, WP22 WD=78.8, rdvb =8.2m, WP22 WD=81.0, rdvb =11.8m, WP23 WD=81.0, rdvb =8.2m, WP23 ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  13. Discussion: Way Point 21(0.98km), LF(5mins) + MF(5mins) Tonal, 8 fres ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  14. Way Point 22(2.98km), LF(5mins) Tonal(53, 103 203, 253)Hz ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

  15. Way Point 23(4.98km), LF(5mins) Tonal(53, 103 203, 253)Hz ONR SW06 Workshop, January, 30-31, 2007 San Diego, CA

More Related