The criteria that define the operational status of each AIS-receiving Station are as follows:
- Online (Green Antenna): At least one valid AIS message sent during the last 30 minutes with the covering area larger than 400 square kilometers and the maximum distance more than 11 nautical miles.
- Low coverage (Orange Antenna): At least one valid AIS message sent in the last 30 minutes, with the covering area smaller than 400 square kilometers and the maximum distance less than 11 nautical miles.
- Online – No Data (Orange Antenna): No valid AIS message sent during the last 30 minutes but at least one keep-alive message within the last 2 hours.
- Recently Offline: No valid AIS message sent during the last 30 minutes and no keep-alive message within the last 2 hours.
- Offline (Red Antenna): No valid AIS message sent during the last 60 minutes.
- Inactive: No valid AIS message has been received since it was created. It is automatically deleted after 10 days.
The Status field is visible on various MarineTraffic spots such as the Station Details page or the Station InfoWindows where you can search through all the AIS-receiving Stations that comprise the MarineTraffic Network.