Reference

Maritime intelligence glossary

Plain-language definitions of the signals, methods, and workflows behind Axiom Overwatch.

Vessel Tracking

The radio system vessels use to broadcast identity, position, speed, and course.

Following a ship's position and movement over time from AIS broadcasts.

A daily grid of H3 cells used to compare vessel-position density by type.

A measure of how long vessels wait to berth at a port and how many are queued.

Detected state transitions of vessels at a port from AIS positions.

A port-scoped polygon that turns AIS positions into arrival, anchorage, berth, and departure events.

Measuring a vessel's draft change to infer how much cargo was loaded or discharged.

Estimating loaded or discharged tonnage from draft change and vessel hydrostatics.

A method-ranked tonnage inference that prefers survey or hydrostatic inputs over a generic draft-change proxy.

Transferring cargo between two vessels at sea, sometimes to evade detection.

Vessels that switch off AIS to hide their location, often for sanctions evasion.

Checking vessels and owners against sanctions and ownership-change signals.

A period without a qualifying AIS position that warrants review, not proof of concealment.

A named input that contributes evidence and weight to a vessel risk score.

Tracking how grain, oil, and other commodities move between ports by vessel.

Weekly tonnage forecasts for grain loadings at export ports.

A consistency measure comparing a vessel's AIS-declared destination with the port it actually visits.

Satellite vegetation index used as crop-health context for commodity flows.