Satellite data for ship and oil spill detection
By Mazdak Ghasemi · Last checked 22 October 2026
Which satellite data is best for detecting ships and oil spills?
Radar, usually Sentinel-1: it images the sea in any weather, by day or night. EMSA's CleanSeaNet, Europe's satellite oil spill and vessel detection service, is built on regular radar images, and Sentinel-1C and 1D also carry AIS receivers, which can highlight ships not broadcasting their identity. In Australia, AMSA's contingency planning guideline lists satellite radar as an option for monitoring large areas of sea, alongside the aerial surveillance it recommends.
Which data to use
| Data | Resolution | Revisit | Record | Use |
|---|---|---|---|---|
| Sentinel-1 radar | 10 m pixels | 6 days | From April 2014 | Ships and possible slicks in any weather; AIS on Sentinel-1C and 1D |
| Sentinel-2 | 10 m | 5 days | From June 2015 | Cloud-free daylight images of land and coastal waters |
| ALOS-2 PALSAR-2 (commercial) | 3 to 10 m | 14 days | Varies by area | Finer radar detail where tasked |
How it is done
- Screen radar images of the area for vessels and possible slicks.
- Compare detected ships with AIS: ESA notes the combination can highlight ships that are not broadcasting their identity and location.
- Confirm possible slicks from the air or a vessel before acting; AMSA recommends aerial surveillance for monitoring slicks.
Limits to know
- Small boats can be missed at 10 m pixels, and rough seas raise false alarms.
- Calm water and natural films can look like oil on radar, so detections need checking.
- Sentinel-2 sees only in cloud-free daylight, and its systematic coverage is of land and coastal areas.
- Revisit gaps mean a satellite will not see every spill as it happens.
Who does this in practice
- EMSA's CleanSeaNet orders radar satellite images regularly and gives analysed images to national contact points in near-real time.
- AMSA trialled satellite radar oil spill detection with Kongsberg Satellite Services in 2012–13, receiving data within 60 minutes.
What Terrascout returns
The real result for “Detect ships and oil spills off Port Hedland WA” (Port Hedland, WA), captured on 22 October 2026: the top 1 of 6 sources.
Radar (SAR) sources are listed first: the brief is about ships or pollution at sea, which radar detects in any weather, by day or night.
| # | Source | Type | Resolution | Cost | Fit |
|---|---|---|---|---|---|
| 1 | Sentinel-1 C-SAR | Radar | 10 m | No data fee | 95 |