Technical companion
Definitions, cohorts and verified evidence
This page records the comparison keys, reported statistics, package boundaries and exclusions behind the reader report.
Comparison definition
Every signed value is geology-informed seabed transmission loss (TL) minus historical fixed seabed TL. Positive means more propagation loss under the geology-informed treatment and therefore lower modeled received level for an unchanged source level. TL is not received level and this report does not compare against measured pressure.
The historical HA01 tuple is 1,668.5 m/s, 1.813 g/cm³ and 0.74 dB/wavelength. The geology-informed route uses OceanData to resolve mapped or scenario evidence, OceanAcoustics to select or mix one complete tuple, and RAMTools to compile the range-varying seabed. The recorded release chain is OceanAcoustics 0.1.25, OceanData 0.1.27, RAMTools 0.1.48 or 0.1.49 as recorded by each package, and RAM 0.1.21.
| Matched cohort | n | Plotted measure | Median difference (dB) | 5th to 95th (dB) | Full range (dB) | Median range-summary difference (dB) |
|---|---|---|---|---|---|---|
| Juan paths to the H01W1 hydrophone, 63 Hz | 678 | Endpoint TL | +3.209 | -5.689 to +14.574 | -21.021 to +28.767 | |
| Selected paths at HA01 and HA10, 63 Hz | 18 | Endpoint TL | +4.852 | -3.690 to +10.422 | -25.048 to +11.004 | +3.669 |
| Juan 26 March dense track, 63 Hz | 180 | Endpoint TL | +1.863 | -2.261 to +4.949 | -14.909 to +12.587 | |
| Juan 26 March dense track, 80 Hz | 180 | Endpoint TL | +1.915 | -1.948 to +5.898 | -7.661 to +10.402 | |
| January 2025 H01W array reciprocal grid, 63 Hz | 1,800 | Final range sample | +10.247 | -2.505 to +43.615 | -22.982 to +105.862 | +4.654 |
| January 2025 H01W array reciprocal grid, 80 Hz | 1,800 | Final range sample | +10.776 | -1.615 to +36.246 | -21.983 to +148.930 | +4.599 |
| February 2026 holdouts and refinements, 63 Hz | 600 | Final range sample | +15.146 | -0.313 to +36.260 | -13.341 to +90.679 | +6.356 |
Robust range summaries
| Cohort | Statistic |
|---|---|
| Selected 18 paths, 63 Hz | Endpoint median +4.852 dB, range -25.048 to +11.004 dB. Trailing-1-km linear-power median +3.669 dB, range +0.690 to +9.082 dB. |
| January 2025 grid, 63 Hz | Median-over-range median 4.653976 dB, 5th to 95th 2.696078 to 7.861258 dB. Endpoint median 10.246899 dB. |
| January 2025 grid, 80 Hz | Median-over-range median 4.598673 dB, 5th to 95th 2.805135 to 7.920963 dB. Endpoint median 10.776382 dB. |
| February holdouts and refinements, 63 Hz | Median-over-range median 6.355860 dB. Trailing-1-km median 16.429768 dB. |
| January AIS derivative, 63 Hz | 1,411 nearest-computed-sample rows; TL median 3.799347 dB. |
| January AIS derivative, 80 Hz | 1,411 nearest-computed-sample rows; TL median 3.488503 dB. |
Declarative visualization binding
The report applies visualizer.comparison_table.v1 to seven separate derived.comparison_table materializations. The renderer shows paired historical and geology-informed TL values, an equality line, and the signed difference against the cohort's declared coordinate. Selection state remains local. The report never pools the cohorts.
| Cohort | Rows | Coordinate |
|---|---|---|
| Juan paths to the H01W1 hydrophone, 63 Hz | 678 | Source range (km) |
| Selected paths at HA01 and HA10, 63 Hz | 18 | Source range (km) |
| Juan 26 March dense track, 63 Hz | 180 | Minute index |
| Juan 26 March dense track, 80 Hz | 180 | Minute index |
| January 2025 H01W array reciprocal grid, 63 Hz | 1,800 | True bearing (degrees) |
| January 2025 H01W array reciprocal grid, 80 Hz | 1,800 | True bearing (degrees) |
| February 2026 holdouts and refinements, 63 Hz | 600 | True bearing (degrees) |
The machine-readable evidence index preserves the source identities and paths.
Completion and exclusion boundary
The completion matrix records 4,536 matched February base-bearing pairs at each of 63 and 80 Hz, 1,800 January pairs at each frequency, 600 verified 63 Hz holdout/refinement pairs, and the direct-path families described in the reader report. Completion alone does not supply a report statistic. This report only makes numerical claims from the local paired tables listed in the evidence index.
The HA03/HA08 artificial-water pilot is non-admissible and excluded. The former paired HA03/HA08 atlas is outside current desired RAM coverage; any saved fields remain historical sensitivity evidence. Temporary mud-completion and factor-isolation lineages are also excluded. Historical artifacts remain unchanged.
Scientific limit
This is a historical-evidence sensitivity report. The current desired-state contract uses the geology-informed seabed for new RAM coverage and keeps fixed-seabed fields as historical comparison evidence. That policy does not prove that the geology-informed treatment is physically correct for any path. This report fits no correction and does not retrospectively rewrite earlier TL products.