Weather Airborne Phased Array Radar (APAR): Next-generation radar for weather research Winter 2015 ______________________________________________________________________________________ I. Description Airborne radar is a critical tool for studying weather and related hazards, especially over rugged terrain or the open ocean, where other tools can have major limitations. Now, major advances in cellular technology, component miniaturization, and radar antenna simulation software have paved the way for a next-generation radar being designed by NCAR for installation on the NSF/NCAR C-130 aircraft. Instead of relying on a single dish, this airborne phased array radar (APAR) will incorporate thousands of miniature transmitters and receivers mounted on a rectangular plate. It will feature four removable, C-band active electronically scanned array antennas mounted on top, both sides, and the bottom of the aircraft. NCAR APAR will operate like many radars in one, enabling researchers to sample the atmosphere far more frequently. Data with greatly improved spatial and temporal resolution will be gathered along a plane’s flight track, with significantly reduced signal loss in heavy precipitation. The APAR wavelength (5-cm) allows measurements of storm dynamics and microphysics deeper inside the storms, while allowing the aircraft to remain at a safer distance. The system will also feature dual polarization capability that can distinguish between raindrops, ice crystals, and snowflakes. The result will be improved observations and predictions of dangerous rain and snow events, including severe thunderstorms, hurricanes, winter storms, and other hazardous, difficult-to-study weather conditions. II. Stage of Research Design is complete. Implementation is divided into three phases: • Build a prototype radar transmitter/receiver (mid-2015) • Build a full-size single-panel prototype for ground testing (2018) • Develop the complete APAR four-panel system for C-130 installation and operations (2022)