Table 3 Comparison of delta AIC values from the step-wise GAM procedure for the best-fit model in each frequency band (blank boxes indicate that the covariate was not included in the best-fit model). AIC values are compared to the null model and greatest delta AIC values indicate the most improvement from the null model
Variable | delta AIC | |||||||
|---|---|---|---|---|---|---|---|---|
Ship Design | Broad-band | 16 Hz | 31.5 Hz | 63 Hz | 124 Hz | 250 Hz | 500 Hz | |
Length | LOA | 30.6 | 40.7 | 52.8 | 6.1 | 3.1 | ||
Gross tonnage | GT | 12.5 | 50.0 | 16.5 | 11.9 | |||
Horsepower | HP | 24.9 | ||||||
Service speed | SSPD | 32.9 | 39.1 | |||||
Draft | DFT | |||||||
Identification | ID | |||||||
Year built | YB | 13.6 | ||||||
Ship Operational | Broad band | 16 Hz | 31.5 Hz | 63 Hz | 124 Hz | 250 Hz | 500 Hz | |
Speed | SPD | 323.7 | 291.9 | 257.9 | 203.4 | 173.2 | 206.8 | 181.4 |
Range | RAN | 10.5 | 17.2 | 6.4 | 2.3 | |||
Proportion of speed | PSPD | 9.2 | 1.9 | |||||
Other ship | OTH | 2.6 | 4.9 | |||||
Tones | TONE | 11.8 | 10.0 | 30.6 | ||||
Environmental | Broad band | 16 Hz | 31.5 Hz | 63 Hz | 124 Hz | 250 Hz | 500 Hz | |
Month | MTH | 25.9 | 37.8 | 46.5 | 11.0 | 12.2 | 18.8 | 36.9 |
Wave height | WVHT | 4.8 | 15.5 | 13.4 | ||||
Wave direction | MWD | 4.8 | 3.9 | |||||
Current direction | CDIR | 3.8 | 3.0 | 4.7 | ||||
Wave period | DPD | |||||||
Wind direction | WDIR | |||||||
Wind speed | WSPD | |||||||
