Long-Range Detection and Location of Shallow Underwater Explosions Using Deep-Sound-Channel Hydrophones

Underwater explosions with energy yields equivalent to less than 40 kg of TNT are detected at hydrophones in the deep-sound channel at distances up to 16 000 km. The arrival times and azimuths of the signals are compared with values based on known explosion locations and times. Arrival-time mismatches are of the order of 10 s. Azimuth mismatches are less than half a degree. Signal arrival times and azimuths are input to a seismological global association algorithm and the resulting estimates of explosion times and locations are compared with actual values. Estimated locations are shown to lie within tens of kilometers of the actual explosions and estimated explosion times to be correct to within tens of seconds. All location estimates have spatial error ellipses that contain the location of the relevant explosion.