Ray trace modeling of underwater sound propagation. Documentation and use of the PlaneRay model
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OriginalversjonSINTEF Rapport A21539, 49 p. SINTEF, 2011
PlaneRay is a ray tracing program for modeling of underwater acoustic propagation s with moderately range-varying bathymetry and bottom parameters. The sound speed of the water may vary with depth, but not with range. The bottom can be a fluid sedimentary layer over an elastic half space with geo-acoustic properties that may vary with range. No rays are traced into the bottom, but the bottom interaction is modeled by local plane wave reflection coefficients. The model uses a unique sorting and interpolation routine to determine all eigenrays connecting a source with a number of receivers positioned on a horizontal line. For each eigenray, the model calculates the trajectories, travel times and amplitudes and constructs the complete frequency domain transfer function by coherent addition of all contributions of the multiple arrivals. Multiplying with the spectrum of a source signal and Fourier transformation of the product yields the time responses of the received signals. A unique feature of the model is that the contribution of the various multipath arrivals are evaluated separately, thereby enabling the user to study the structure of the field in detail. This report gives a description of the model and presents a number of illustrative cases. The accuracy of the ray model and the use of the plane wave reflection coefficients to represent the effects of a layered bottom are discussed by comparing the time and frequency domains solution of the ray model with the results from other established propagation models.