Objective Prediction Of Slant Visual Range During Advective Fog Situations

The final phase of the Air Force Geophysics Laboratory development and evaluation of a remote tower slant visual range (SVR) system is described. Remote tower forward scatter meter measurements of atmospheric extinction coefficient are used to estimate the SVR in the simulated approach zone. Three prediction techniques, Markov, Regression Estimate of Event Probabilities (REEP), and Equivalent Markov, are evaluated and yield probability estimates of below-limit SVR conditions for forecast times to 1 h. For Categories I and II conditions, such a system would have a probability of detection of below-limit SVR conditions of 91%. The Equivalent Markov technique is shown to provide accurate and reliable forecasts and yield slightly better results than Markov and REEP. (Author).