Achieving the transparent ocean

Our common impression is that radar systems monitor the vast majority of the airspace above the earth’s surface. Safe travel is nearly taken for granted, and for the purposes of national security there is a constant close eye on the comings and goings through our airspace. The same cannot be said for under the ocean’s surface, from way out at sea, to near our coast, and within our harbors and waterways. The need for the long-coveted “Transparent Ocean” is evident, and in this paper we explore the visionary aspects of achieving this goal. This includes reviewing concepts and a framework around which state-of-the-art often stove-piped techniques in underwater acoustics, signal processing, and acoustical oceanography, along with non-acoustic modalities including radar and EOIR, are combined into an integrated system.