Automated continuous radar calibration using the self-consistency of dual-polarimetric variables in rain

End-to-end, absolute calibration of power measurements in a radar system remains to this day a challenging problem. Even the U.S. NEXRAD system has recently been shown to have a 2-3 dB discrepancy between adjacent radars. Part of the problem is that the best traditional methods of calibration involve procedures that are time-consuming to perform once, let alone on a regular basis to ensure continued optimal system performance.

With the advent of dual-polarimetric radar measurements, the so-called “self-consistency” relationship between Z, ZDR, and KDP in rain has been shown to be useful for absolute calibration of Z and ZDR. We have recently implemented this technique within the Enterprise Doppler Graphics Environment (EDGE) for deployment with our radar systems. This implementation runs continuously and with no user intervention required. We demonstrate the accuracy of the automated calibration using data from OU-Prime, a C-band radar located in Norman, OK.