Weather Deck vs Enclosed Deck — Two Different Detection Problems

A vehicle deck open to weather and a vehicle deck below the freeboard are different operating environments for a detection layer. The same sensor architecture works on both — the calibration and the algorithmic thresholds do not.

Weather deck specifics

• Strong solar gain on horizontal vehicle surfaces — coherence windows have to handle large environmental deltas.
• Wind-driven thermal mixing reduces local thermal stratification.
• Rain and salt-spray exposure on the sensor itself.
• Line-of-sight detection is more available because vehicles are not stacked under overhead structure.

Enclosed deck specifics

• Mechanical ventilation produces moving thermal gradients that look like anomalies if not modelled.
• Cargo density is higher; cell field-of-view crops to one or two vehicles.
• No solar component, smaller environmental swings — tighter baseline.
• No line-of-sight from any single mounting point — distributed sensing is required.

Implications for the regulatory split

SOLAS II-2/20 captures suppression on weather decks. The detection conversation on weather decks is closer to the yard-monitoring problem than to the enclosed-deck problem — and it benefits from camera-based imaging as a secondary. Enclosed decks remain a per-vehicle thermal grid problem.