Underwater acoustic field extrapolation using vertical reference arrays

Conventional methods for predicting acoustic propagation through a region of ocean require detailed knowledge of the environment. A method that acoustically “calibrates” the medium through the use of vertical transmit and receive arrays is discussed. By combining (via a generalized form of Huygens´ principle) the measured calibration data with field estimates based on limited local environmental knowledge, the acoustic field due to a source outside the calibration region can be calculated. The mathematical formulation for this “extrapolated” field is discussed. The effects of mismatch between the estimated local environmental information and the true propagation conditions are also examined