ER-2 X-band Radar (EXRAD) for Cloud, Precipitation and Wind Measurements

Following the successful development and field campaigns of the X-band (9.6 GHz) ER-2 Doppler (EDOP), the W-band (94 GHz) Cloud Radar System (CRS), and the Ku/Ka (13 GHz/35GHz) dual frequency High-altitude Imaging Wind and Rain Airborne Profiler (HIWRAP), a compact, light weight, ER-2 X-band Radar (EXRAD) was developed and test flown on ER-2 by the NASA Goddard Space Flight Center (GSFC) High-altitude Airborne Radar (HAR) group. EXRAD is a combined precipitation radar and scatterometer that measures both the 3D cloud/precipitation structure and surface winds with fixed nadir and conical/cross-track scanning beams. It is developed to replace the previous aging ER-2 Doppler Radar (EDOP) with enhanced capabilities. EXRAD utilizes a high peak power transmitter (TWT) and two flat plate antennas. It is more compact and lighter than its predecessor EDOP. In addition, EXRAD uses a cutting-edge FPGA onboard digital receiver and processor with significantly enhanced capabilities.

EXRAD was successfully integrated on ER-2 in early 2013. Three test flights were then carried out for radar performance evaluation. This paper describes EXRAD development rationale, instrument hardware and software, and ER-2 integration and test flights. Preliminary data is then presented.