Description
The ER-2 X-band Doppler Radar (EXRAD) is a dual-beam, 9.6 GHz X-band Doppler radar used for airborne weather observations. It is designed to operate at high altitudes, onboard the NASA ER-2 research aircraft (ER-2). EXRAD operates using two offset-feed parabolic antennas including a fixed nadir-pointing antenna and a scanning antenna that can scan conically or cross-track (Figure 1). EXRAD was originally built to operate onboard Global Hawk, however, it was reassigned to operate primarily onboard the ER-2 to replace the aircraft’s aging ER-2 Doppler Radar (EDOP). EXRAD and EDOP are very similar instruments and therefore have comparable measurement capabilities. The main difference is the conical/cross-track scanning antenna that is included with EXRAD compared to the fixed forward-pointing antenna with EDOP.