Ka-band ARM zenith profiling radar (KAZR) network for climate study

The Atmospheric Radiation Measurement (ARM) Climate Research Facility has deployed Ka-band ARM zenith profiling radar (KAZR) at its fixed and mobile facility. KAZR plays a crucial role in providing long-term observation of cloud systems for climate research. Therefore, it is critical to perform routine end-to-end system evaluation to assess the performance of the radar. Calibration of the zenith pointing radar with very narrow beam widths has always been a very difficult task. In addition to the narrow vertical beam the use of frequency diversity pulse compression waveform with the newly deployed KAZR makes it even more challenging to calibrate the radar. The addition of a co-located Ka-SACR with short pulse and pulse compression capability provides an invaluable tool to cross-calibrate the KAZR with Ka-SACR. Both, SACR and KAZR can be calibrated with the traditional radar equation for volume target. However, the use of corner reflector calibration with SACR provides an additional constraint to verify the calibration state of KAZR. One of the main design goals with KAZR was that it be deployed as an unmanned operational system. This paper presents the salient features of KAZR system design and also present a methodology for cross-calibration of the zenith pointing cloud radar with co-located scanning cloud radar.