Layered coverage across the strait
No single sensor provides a complete operating picture. StraitWatch combines shore reception for low-latency local coverage with satellite reception for continuity beyond terrestrial range, then adds environmental and navigational context.
Position and identity feeds
AIS messages provide the core observations used to locate, identify, and classify vessel movement. The two reception paths overlap so tracks can be checked against independent observations.
Terrestrial AIS
Shore-based receivers capture nearby broadcasts with low latency throughout the monitored passage.
- Position, course, and speed
- MMSI and navigational status
- Vessel name, type, and destination
Satellite AIS
Satellite reception extends observation beyond shore range and helps fill gaps created by terrain or receiver availability.
- Offshore position continuity
- Track corroboration
- Delayed-message reconciliation
Operational and environmental context
Supporting layers explain the conditions around each vessel track and help analysts distinguish traffic changes from weather, geography, or navigational restrictions.
| Source category | Used for | Typical update |
|---|---|---|
| Navigational notices | Closures, restrictions, hazards, traffic instructions, and active advisories. | On publication |
| Weather observations | Wind, visibility, air pressure, sea state, and short-range passage conditions. | Near real time |
| Ocean conditions | Wave height, sea temperature, tidal current, and directional flow. | Hourly |
| Natural Earth 1:10m | Coastline and geographic reference used in the operating map. | Reference layer |
| Vessel registries | IMO identity, vessel class, flag, dimensions, and identity corrections. | As available |
How recent data is communicated
Dashboard timestamps use UTC. “Last signal” refers to the age of the latest accepted vessel observation, while “Last verified” records the most recent successful operating-status check.
Position feed
Updates continuously as validated AIS messages arrive. Satellite messages may appear later than terrestrial reports.
Environmental feed
Updates on each station’s reporting cadence; the dashboard shows the latest complete observation set.
Advisories
Added when an operational notice is received and verified, then retained until it expires or is withdrawn.
Reference data
Registry and map layers are refreshed separately because they change less frequently than live observations.
Checks applied before display
Each incoming report is evaluated for valid coordinates and time, identifier consistency, plausible movement, duplication, and agreement with the recent track. Failed checks are quarantined rather than added to the operating picture.
Reject malformed coordinates, impossible timestamps, and messages without the identifiers needed for safe matching.
Compare speed, course, and distance against the vessel’s preceding accepted observation.
Monitor expected reporting intervals and lower confidence when reception becomes stale or incomplete.