26 March 2026 · 60 one-minute centres · H01W hydrophones H01W1, H01W2 and H01W3 · 63 and 80 Hz

The seabed treatment changes RAM TL in both directions

The fixed and geology-informed runs use the same source track, H01W hydrophones, water, bathymetry, numerical grid and 6.16 m source depth. Only the bottom treatment changes.

Across 360 matched hydrophone–frequency–minute combinations, source-aware minus fixed TL has a median of +1.88 dB, but individual changes range from −14.91 to +12.59 dB. There is no scalar correction.

Result

A modest median shift, with large coherent excursions

720 / 720current RAM cases passed

+1.88 dBmedian source-aware minus fixed TL

−2.22 to +5.865th–95th percentile (dB)

−14.91 to +12.59complete range (dB)

The triplet morphology correlation with the provisional one-minute measured series rises from 0.530 to 0.588 at 63 Hz and from 0.363 to 0.410 at 80 Hz. Those are descriptive shape comparisons, not calibrated sound-level validation or attribution.

Queryable RAM comparison

Follow the two TL series minute by minute

FrequencyHydrophone

fixed historicalgeology-informed source-awaresource-aware minus fixed

Static fallback: every thirtieth paired row
UTC	Hydrophone	Hz	Fixed TL (dB)	Source-aware TL (dB)	Difference (dB)
2026-03-26T10:10:30Z	H01W1	63	74.20	75.91	+1.71
2026-03-26T10:15:30Z	H01W1	63	72.95	73.85	+0.90
2026-03-26T10:20:30Z	H01W1	63	73.65	74.87	+1.22
2026-03-26T10:25:30Z	H01W1	63	69.08	69.62	+0.54
2026-03-26T10:30:30Z	H01W1	63	69.35	71.34	+1.99
2026-03-26T10:35:30Z	H01W1	63	72.22	73.69	+1.47
2026-03-26T10:40:30Z	H01W1	63	71.16	73.11	+1.95
2026-03-26T10:45:30Z	H01W1	63	78.75	80.49	+1.74
2026-03-26T10:50:30Z	H01W1	63	80.38	80.53	+0.16
2026-03-26T10:55:30Z	H01W1	63	78.44	79.48	+1.03
2026-03-26T11:00:30Z	H01W1	63	83.28	90.85	+7.57
2026-03-26T11:05:30Z	H01W1	63	87.29	89.59	+2.30

Validated 63 Hz dense-track TL, modeled received-level and provisional measured-level comparison — Validated 63 Hz static evidence. It shows all three hydrophone series and the H01W triplet linear-power mean.

Validated 80 Hz dense-track TL, modeled received-level and provisional measured-level comparison — Validated 80 Hz static evidence under the same track and branch comparison.

Interpretation boundary

What this comparison can and cannot establish

It isolates seabed treatment

Source and receiver geometry, water, bathymetry, frequency, source depth, time sampling and extraction are held equal.

It does not validate absolute sound level

The measured curve is a provisional nominal-band level. The modeled curve uses one fixed JOMOPANS-ECHO source level and omits other ships.

It preserves coherent sensitivity

The large positive and negative excursions are path-specific RAM results, not a stable bias to add to another calculation.

It does not reopen attribution

No acoustic travel-time shift is applied here, and the result does not reopen the closed Lloyd-mirror test.