The Multifunction Phased Array Radar (MPAR) is one potentially cost-effective solution to meet the surveillance needs and of several agencies currently using decades-old radar networks. These agencies including the National Oceanic and Atmospheric Administration s (NOAA) National Weather Service (NWS), the Federal Aviation Administration (FAA), the Department of Defense (DOD) and the Department of Homeland Security (DHS) have many and varied requirements and possible applications of modern radar technology. This book analyzes what is lacking in the current system, the relevant capabilities of phased array technology, technical challenges, cost issues, and compares possible alternatives. Both specific and overarching recommendations are outlined.