| It is suprisingly easy to lose track of things in the ocean. Even big things. Ships. Aircraft. If the transponders are headed to X whilst the ship is headed to Y, it may take you a while before you realise that the ship isn't also headed to X. At which point you now have the problem of determinging which of those fuzzy, cloud-obscured smudges is your ship, and which is someone else's. Radar can pick up ships, but it also detects, say, rogue shipping containers, of which there are a suprisingly large number. Existing tracking systems rely on AIS transponders: http://www.bbc.com/news/science-environment-28372461 Yes, Google can track ships at sea. But it's also relying on AIS, rather than imagery: http://breakingdefense.com/2012/05/google-satellites-can-tra... LA-bound cars might be hard. A shipment bound for the Philippines, or India, or elswhere along the Indian or South China seas, quite possibly much easier. |