{"schemaVersion":"1.0","id":"whats-on-the-river","dataset":"live-ships","title":"What is on the river","description":"The Thames is a working waterway, and it broadcasts.","methodology":"AIS transmissions heard over Greater London, via AISStream. Unlike every other feed here this one is a broadcast rather than a request: vessels transmit when they choose to, so there is no endpoint that answers what is on the river now — the server has to have been listening. It holds one socket open and accumulates what it hears, forgetting a vessel after twenty minutes of silence. Carrying AIS is mandatory for larger commercial craft and optional for small ones, so this is what the river is broadcasting rather than a census of what is on it. The count climbs for the first several minutes after a deploy while the table fills.","category":"transport","categoryLabel":"Transport","cadence":"live","placeholder":false,"landingPage":"https://londongraph.com/g/whats-on-the-river","markdown":"https://londongraph.com/g/whats-on-the-river/index.html.md","source":{"name":"AISStream","url":"https://aisstream.io/","licence":"AISStream terms of use"},"observations":null,"areaStatistics":null,"visualizations":[{"id":"overview","label":"Map","description":"The Thames is a working waterway, and it broadcasts.","url":"https://londongraph.com/g/whats-on-the-river","renderer":"primary","default":true,"timeControl":"inherit","datasets":[],"transform":null,"controls":null,"metrics":[],"caveat":null},{"id":"vessel-types","label":"Vessel types","description":"Show the mix of vessel classes currently broadcasting.","url":"https://londongraph.com/g/whats-on-the-river?view=vessel-types","renderer":"live-summary","default":false,"timeControl":"inherit","datasets":[],"transform":null,"controls":null,"metrics":[],"caveat":null},{"id":"speed","label":"Speed","description":"Show the distribution of reported vessel speeds.","url":"https://londongraph.com/g/whats-on-the-river?view=speed","renderer":"live-summary","default":false,"timeControl":"inherit","datasets":[],"transform":null,"controls":null,"metrics":[],"caveat":null}],"availability":"metadata-only","note":"Live values are intentionally served by rate-limited application feeds, not this crawlable record."}