NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV SAN DIEGO CA
Results from a unique analytical and measurement effort to assess low-altitude, short-range, radar detection capabilities in an evaporation ducting environment validate propagation model predictions of reduced radar detection ranges within the radio horizon. In addition, discrepancies between measured and predicted radar data demand a close examination of both meteorological data and surface layer theory. At ranges near and beyond the horizon, radar detection crucially depends both on the surface layer refractivity profile and on the adjacent mixed layer refractivity profile. A unified boundary layer model, an empirical model to merge the surface layer with the mixed layer, is described. Other discrepancies, which are thought to be caused either by inadequate surface layer modeling perhaps the moisture stability function or by inadequate boundary layer meteorological measurements, suggest the need for improvements in surface layer modeling and the need for new techniques to measure the refractivity structure. The combination of direct boundary layer surface and mixed layer meteorological measurements, remotely sensed radar measurements, and advanced numerical modeling capability provides valuable insight for a better understanding of the atmospheric boundary layer and its effects on the radar detection of low-altitude short-range targets.