PROBLEM TO BE SOLVED: To provide an ocean radar system which achieves enhanced Tsunami detection accuracy and is capable of monitoring a wide range of area, without using two radars and prediction patterns.SOLUTION: An ocean radar system includes; a flow velocity vector estimation unit 6 which transforms a velocity vector VDin a direction of radar vision indicated by Doppler effect of a range cell with a Tsunami wavefront estimated by a wavefront estimation unit 5, into a flow velocity vector VDin a propagating direction of the Tsunami; and a Tsunami detection unit 7 which verifies whether the flow velocity vector VDtransformed by the flow velocity vector estimation unit 6 is a vector actually representing the flow velocity of the Tsunami or not and, if the vector actually represents the flow velocity of the Tsunami, acknowledges the occurrence of the Tsunami.
