TABLE IV.
FWHM Error Parameter C For Membrane and Needle Hydrophones
| Hydrophone Type | Membrane | Membrane | Needle | |||
|---|---|---|---|---|---|---|
| Data | Simulation | Expt | Simulation | |||
| Method | SB-SC | SB-SC | SB-SC | |||
| σq | σm | SI | C (RMSD) | C (RMSD) | C (RMSD) | |
| Linear | 0 | 0 | 0 | 5% (2%) | 9% (4%) | 4% (3%) |
| Nonlinear | 0.5 | 0.4 | 4% | 16% (4%) | 14% (5%) | |
| Nonlinear | 1.0 | 0.8 | 12% | 30% (5%) | 30% (10%) | 27% (6%) |
| Nonlinear | 2.0 | 1.6 | 29% | 62% (9%) | 57% (10%) | |
| Nonlinear | 3.0 | 2.2 | 35% | 74% (10%) | 67% (12%) | |
| Nonlinear | 4.0 | 3.1 | 45% | 100% (13%) | 89% (14%) | |
| Nonlinear | 5.0 | 3.9 | 49% | 120% (20%) | 109% (20%) | |
Linear model functions Cx were used to fit to relative errors in FWHM, where x = dg / (λ1F/#). Nonlinearity indexes are σq (local distortion parameter), σm (nonlinear propagation parameter), and SI (spectral index). RMSD: root-mean-squared difference between data and functional fits. SB-SC: scan-based spatial convolution.