THE EDOP RADAR SYSTEM ON THE HIGH-ALTITUDE NASA ER-2 AIRCRAFT

The NASA ER-2 high-altitude (20 km) aircraft that emulates a satellite view of precipitation systems carries a variety of passive and active (lidar) remote sensing instruments. A new Doppler weather radar syste m at X band (9.6 GHz) called the ER-2 Doppler radar (EDOP) has been de veloped and flown on the ER-2 aircraft. EDOP is a fully coherent Doppl er weather radar with fixed nadir and forward pointing (33 degrees off nadir) beams that map out Doppler winds and reflectivities in the ver tical plane along the aircraft motion vector. Doppler winds from the t wo beams can be used to derive vertical and along-track air motions. I n addition, the forward beam provides linear depolarization measuremen ts that are useful in discriminating microphysical characteristics of the precipitation. This paper deals with a general description of the EDOP instrument including the measurement concept, the system configur ation and hardware, and recently obtained data examples from the instr ument. The combined remote sensing package on the ER-2, along with EDO P, provides a unique platform for simulating spaceborne remote sensing of precipitation.