Practical Application of IREPS (Integrated Refractive Effects Prediction System).
Abstract
The Integrated Refractive Effects Prediction System (IREPS) has been used operationally by the U.S. Navy since 1978. Subsequently, there have been questions from the fleet concerning IREPS assessments of system performance under strong (30-40 metres) evaporation ducting conditions that have not been borne out by observed system performance. Additionally, the IREPS climatological propagation assessments developed from the National Climatic Data Center data base show a distinctly bimodal distribution of evaporation duct heights that is difficult to justify. Errors in system performance assessment arise in three areas: (1) the environmental measurements, (2) the meteorological models used to determine evaporation duct heights, and (3) the propagation models used to quantify propagation conditions. Only the first two of these areas are investigated in this report. The application of the IREPS evaporation duct model in assessing and the sensitivity of the model to meteorological measurements are examined. The unexpectedly high occurrence of evaporation duct height greater than 40 metres is related to stable conditions (positive air-sea temperature difference) in the surface layer. The existence of stable conditions over the ocean is analyzed in terms of meteorological conditions and temperature measurement accuracies. Comparisons of air-sea temperature difference distributions are made between high quality NOAA data buoy climatological data and archieved ship surface weather data. A modification to the evaporation duct model is proposed and applied to radio-meteorological data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 29, 1984
- Accession Number
- ADA146528
Entities
People
- R. A. Paulus