Calibration of the NASA Dual-Frequency, Dual-Polarized, Doppler Radar

This paper summarizes part of the work performed on the calibration and characterization of the Dual-frequency, Dual-polarized, Doppler Radar (D3R) system. The D3R makes use of pulse compression combined with a three pulse frequency separated waveform to achieve it´s sensitivity while still maintaining a blind range similar to that of a single pulse weather radar. A slightly modified receiver calibration procedure to the one used on conventional weather radar was required to accommodate the use of multiple sub-channels. The use of the calibration loop in both transceivers is described and transmitter output power is shown for a twenty four hour period. Antenna beam (Ku to Ka) co-alignment verification using solar scans is also presented followed by sphere calibration results for the Ku-band radar. Finally, Ku-band reflectivity plots for two events during May 6th, 2012 and May 7th, 2012 are presented.