An Analysis of Surface-Duct Propagation Loss Modeling in SHARPS
NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY STENNIS SPACE CENTER MS
Pagination or Media Count:
The propagation submodels of the Ship Helicopter Acoustic Range Prediction System SHARPS are reviewed within the context of their effectiveness in making accurate predictions for surface-duct environments. The surface-duct propagation loss calculations performed by SHARPS are based on the submodels contained in Active RAYMODE. Fleet messages have been critical of SHARPS target detection range predictions for in-layer and cross-layer sonar- target geometries. A review is presented of those computational methods common to both Active and Passive RAYMODE, most likely to affect surface-duct predictions, and includes a summary of the main features of a surface-duct leakage subroutine found in one of the previous versions of Passive RAYMODE. A means of coupling surface-scattered energy into the normal mode sum is reviewed. The possibility of anomalous surface-duct predictions is briefly addressed and several ways to achieve improved surface-duct propagation loss predictions are recommended.
- Acoustic Detection and Detectors