NASA Goddard High-Altitude Radars—Past, Present, and Future

Goddard has been flying high-altitude (~20 km) radars on the NASA ER-2 for the past 15 years. The first radar flown in 1993 was ER-2 Doppler radar that is an X-band (9.6 GHz) precipitation radar that has two beams, one at nadir and the other 33 degrees forward of nadir. This geometry allowed for calculation of the vertical velocity using fallspeed assumptions, and the along-track horizontal winds. A second radar first flown in 2002, the Cloud Radar System (CRS), is a nadir pointing W-band (94 GHz) Doppler radar also on the ER-2 that is used for cloud studies and is at the same frequency as the CloudSat radar. Two new radars are under development for high-altitudes, the UAV Radar (URAD) and High-Altitude Imaging Rain and Wind Profiler (HIWRAP). These new radars are both conical scanning and the measurements are focused on retrieving horizontal winds in hurricanes and other weather phenomena. URAD was originally designed for the recently acquired Global Hawk UAS by NASA, but is targeted as a replacement for EDOP on the ER-2. This radar utilizes a conventional tube-based transmitter system. HIWRAP is a designed for the Global Hawk under a NASA technology development. HIWRAP has dual Ku & Ka band conically scanned beams to measure wind in hurricanes. HIWRAP is a highly innovative radar utilizing state-of-the-art low peak power transmitters along with pulse compression and impressive real-time processor based on the space-qualified Vertex 5 FPGA. In the presentation, we will present a summary of these high-altitude radars, their capabilities, and plans for future flights with the new HIWRAP system.