Timely prediction of low-altitude radar performance in operational environments using in situ atmospheric refractivity data

Abstract

A shipboard radar decision aid that may be used to predict current low-altitude radar performance and assist the radar operator in maximising system capabilities in the existing propagation environment is discussed. The system, developed for use aboard US Navy AEGIS-class ships, uses expendable rocketborne radiosondes to make high-resolution measurements of the atmo sphere. A version of the Johns Hopkins University Applied Physics Laboratory's electromagnetic parabolic equation (EMPE) propagation model is used to calculate the effects of the measured refractivity environment on the propagation of energy radiated by the radar. A radar modeluses these data in predictions of the system's current low-altitude target detection capabilities. A colour display indicates the size of targets that may be detected through contour shading of a range-height display. The effects of many radar operator controllable options on target detectability may be evaluated in the current propagation environment with this system. A significant portion of the data acquisition-to-display process has been automated. Design and implementation of this system and results of recent at-sea testing are discussed.