JOMOPANS–ECHO
(ship class, length, speed, frequency) → source spectral level
63 Hz162.3 dB
All fields
- Inputs
- ship class · length · speed · frequency
- Native output
- SL, dB re 1 µPa² m²/Hz
- Frequency domain
- 10 Hz–31.5 kHz decidecade centres
- Reference length
- 91.44 m for every class
- Selected class speeds
- 13.1 / 12.4 kn
- Selected spread
- 3.0
- Low-frequency cargo branch
- applies below 100 Hz
- Special case
- Dredger below 3 kn is evaluated at 14 kn
- Source convention
- equivalent monopole; fixed 6 m reference depth
Common scalingbaseline(f, class) + 60 log₁₀(V/Vc) + 20 log₁₀(L/91.44 m)
Displayed quantitysource spectral density at the selected centre frequency
| Class | Vc₁ | Vc₂ | Spread | <100 Hz cargo branch |
|---|---|---|---|---|
| Fishing Vessel | 7.5 | 6.4 | 3 | — |
| Tug | 4.9 | 3.7 | 3 | — |
| Naval Vessel | 14.2 | 11.1 | 3 | — |
| Recreational Vessel | 14 | 10.6 | 3 | — |
| Government/Research | 9.2 | 8 | 3 | — |
| Cruise Vessel | 20.2 | 17.1 | 4 | — |
| Passenger Vessel | 11.7 | 9.7 | 3 | — |
| Bulker | 14.1 | 13.9 | 3 | yes |
| Container Ship | 19.3 | 18 | 3 | yes |
| Vehicle Carrier | 15.8 | 15.8 | 3 | yes |
| Tanker | 13.1 | 12.4 | 3 | yes |
| Dredger | 9.5 | 9.5 | 3 | — |
| Other | 7.4 | 7.4 | 3 | — |