ARMAR - AN AIRBORNE RAIN-MAPPING RADAR

A new airborne rain-mapping radar (ARMAR) has been developed by NASA a nd the Jet Propulsion Laboratory for operation on the NASA Ames DC-8 a ircraft. The radar operates at 13.8 GHz, the frequency to be used by t he radar on the Tropical Rainfall Measuring Mission (TRMM). ARMAR simu lates the TRMM radar geometry by looking downward and scanning its ant enna in the cross-track direction. This basic compatibility between AR MAR and TRMM allows ARMAR to provide information useful for the TRMM r adar design, for rain retrieval algorithm development, and for postlau nch calibration. ARMAR has additional capabilities, including multiple polarization, Doppler velocity measurement, and a radiometer channel for brightness temperature measurement. The system has been tested in both ground-based and airborne configurations. This paper describes th e design of the system and shows results of field tests.