AIS Technology
Satellite AIS Data
Track vessels anywhere on Earth — from the open ocean to arctic routes. Satellite AIS provides true global coverage where terrestrial receivers cannot reach.
What is Satellite AIS?
Satellite AIS (S-AIS) uses satellites equipped with AIS receivers orbiting the Earth to detect vessel transmissions from anywhere on the planet. Unlike terrestrial AIS which is limited to approximately 50km from shore, satellite AIS provides complete global ocean coverage.
Multiple satellites in low Earth orbit continuously scan for AIS signals. When a vessel transmits its position, one or more satellites can receive the signal regardless of how far the ship is from land. This data is then relayed to ground stations and made available through our API.
Satellite AIS is essential for tracking vessels on trans-ocean voyages, monitoring fishing fleets in international waters, and ensuring complete visibility of global maritime traffic.
How Satellite AIS Works
A constellation of satellites provides continuous coverage of the world's oceans.
1
Vessel Transmits
Ships broadcast AIS signals every few seconds containing position, speed, course, and identification data using VHF radio frequencies.
2
Satellite Receives
Low Earth orbit satellites equipped with AIS receivers detect these signals from space, covering areas far beyond the range of shore stations.
3
Data Delivered
Satellites relay data to ground stations, where it's processed and made available through our API within minutes of transmission.
Technical Specifications
Coverage Area
100% of Earth's oceans
Including Arctic, Antarctic, and all international waters
Update Frequency
Minutes
Varies by satellite passes and vessel density
Vessel Capacity
830,000+
Ships tracked globally via satellite
Data Latency
Near real-time
Positions delivered within minutes of transmission
Satellite vs Terrestrial AIS
Understanding when to use satellite versus terrestrial AIS data.
| Aspect | Satellite AIS | Terrestrial AIS |
|---|---|---|
| Coverage | Global oceans, including open sea | Coastal waters (~50km from shore) |
| Update Frequency | Every few minutes | Every 2-10 seconds |
| Best For | Ocean crossings, global tracking | Port operations, coastal monitoring |
| Key Advantage | No blind spots in open ocean | Higher update frequency |
Satellite AIS Use Cases
Industries and applications that rely on global vessel tracking.
Trans-Ocean Voyage Monitoring
Track vessels crossing the Atlantic, Pacific, or Indian Ocean. Monitor complete voyages from departure to arrival without losing visibility mid-journey.
Arctic Route Intelligence
Monitor vessels using Northern Sea Route and Northwest Passage. Critical for understanding polar shipping patterns and ice navigation.
Fishing Fleet Surveillance
Track fishing vessels operating in international waters. Support fisheries management, quota enforcement, and illegal fishing detection.
Sanctions Compliance
Monitor vessels that may attempt to evade detection in open waters. Essential for sanctions screening and trade compliance programs.
Maritime Insurance
Verify voyage routes for underwriting and claims. Satellite AIS provides evidence of actual vessel movements for risk assessment.
Commodity Trading
Track cargo vessels carrying oil, LNG, grain, and other commodities. Understand supply movements and arrival timing for trading decisions.
Frequently Asked Questions
How often does satellite AIS update vessel positions?
Satellite AIS typically provides position updates every few minutes for vessels in open ocean. The exact frequency depends on satellite constellation coverage, vessel density in the area, and satellite pass timing. In busy shipping lanes, updates may be more frequent.
Can satellite AIS track vessels that turn off their AIS?
No — satellite AIS can only track vessels that are actively transmitting AIS signals. However, satellite AIS makes it much harder for vessels to "go dark" undetected, as the global coverage means any gap in transmission is visible regardless of location.
Is satellite AIS data included in all Data Docked plans?
Terrestrial AIS data is included on all plans. Satellite AIS is available on our satellite-tier plans — on those plans, the API automatically serves the best available position for each vessel: terrestrial data near shore (updated every 2-10 seconds) and satellite data in open ocean. Satellite coverage is retrieved per vessel via the single-vessel location endpoint; it is not available on the bulk location endpoint. See our pricing page for plan details.
What is the difference between S-AIS and T-AIS?
S-AIS (Satellite AIS) uses satellites to receive AIS signals globally, including open ocean. T-AIS (Terrestrial AIS) uses shore-based receivers limited to approximately 50km from coast. Terrestrial data is included on all plans; satellite data requires a satellite-tier plan and is available via the single-vessel location endpoint. Learn more about terrestrial AIS.
Related Resources
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