The ocean model needed for satellite submarine detection

How far away are satellites from detecting submarines reliably?

The decisive threshold is a highly accurate model of ocean behaviour; only then can satellites distinguish a probable submarine from ordinary variation.

The answer reframes the problem from simply improving a camera or radar. Oceans produce complex natural motion, temperature, and surface effects that can resemble the traces of an underwater vessel. Once observation and modelling can predict normal behaviour with roughly ninety-percent accuracy, analysts can focus on places where the sea departs from that expectation. Satellite ASW therefore depends as much on oceanography, data fusion, and anomaly detection as on the sensor in orbit.