Assessing the effects of model error on radar inferred evaporative ducts

Abstract

A method for inferring evaporative duct refractivity profiles from radar clutter was introduced by Rogers et al. (2000) called Refractivity from Clutter (RFC). Climatological data from three tactical ocean areas of interest were used to investigation the RFC method using a numerical simulation of an S-band radar. The magnitude of the error introduced by inferring a neutrally equivalent refractive profile from one parameter (radar clutter) was compared against the traditional bulk method which calculates the profile based on environmental measurements. A benchmark for the simulated RFC error was determined by applying measurement errors to the simulated environment and by then calculating refractive profiles using the bulk method. Results of the simulation show that the error introduced by the RFC method is comparable to the error caused by measurement errors for the traditional method. The neutral equivalent profile inferred by RFC exhibited slightly increasing error with height and more than twice the error with frequency when applied to X-band propagation. Finally, a method for investigating tactical impacts of using refractive profiles against low flying anti-ship missiles was developed. Results show that the simulated RFC method determined the detection range of several hypothetical missiles within five percent of the actual predicted range.