NextGen surveillance and weather radar capability (NSWRC) siting analysis
As the current radars that perform weather and aircraft surveillance over the United States age, they must be sustained through service life extension programs or replaced. In the latter case, the radars can be replaced by multiple types of radars with different missions or they can be replaced by scalable multifunction phased array radars (MPARs). State-of-the-art active phased array systems have the potential to provide improved capabilities such as earlier detection and better characterization of hazardous weather phenomena, 3D tracking of noncooperative aircraft, better avoidance of unwanted clutter sources such as wind farms, and more graceful performance degradation with component failure. As the U.S. aviation community works toward realizing the Next Generation Air Transportation System (NextGen), achieving improved capabilities for aircraft and weather surveillance becomes critical, because stricter observation requirements are believed to be needed. Hence, the Federal Aviation Administration (FAA) is considering the MPAR as a possible solution to their NextGen Surveillance and Weather Radar Capability (NSWRC). Cost is one hurdle to the deployment of a modern phased array radar network. One way of lowering the overall cost is to reduce the total number of radars. Because of the overlap in coverage provided by the current radar networks, a unified MPAR replacement network can potentially decrease the total number of radars needed to cover the same airspace. An earlier analysis conducted by MIT Lincoln Laboratory concluded that 510 legacy radars could be effectively replaced by 334 MPARs over the contiguous United States (CONUS). There was, however, some uncertainty whether the spatial resolution used in the terrain blockage calculations was fine enough to accurately depict radar coverage, and also if terminal area coverage was being adequately addressed. This study revisits the siting analysis using a much finer spatial resolution, expands the coverage domain to include all fifty states and U.S. territories, adds the Air Force long-range surveillance radars (FPSs) to the legacy pool, and allows scaling by number of faces per radar. The aim is to provide an estimate of the minimum number of MPARs needed to replace the existing radar coverage. We also provide an extensive statistical compilation of legacy versus MPAR coverage for various observational performance parameters.