Operational Implementation of a Robust Near-Real Time Radar Calibration and Monitoring Technique for Australian Bureau of Meteorology Operational Radars

To address the radar calibration issue in near-real time for a better quality control of radar reflectivity, a robust radar calibration and monitoring technique has been developed at the Australian Bureau of Meteorology (BoM). The technique combines the relative calibration adjustment (RCA) method and results from the periodic comparison of reflectivity between the ground radar and the space-borne radar onboard the Global Precipitation Measurement (GPM) satellite. The RCA method uses the probability distribution of reflectivity in clutter areas near stationary, ground-based radar and provides an automated tool for tracking relative changes in calibration. The GPM calibration technique compares common volumes from the ground and satellite radars to derive the absolute deviation in ground radar calibration. When stable periods are identified with the RCA technique and individual estimates from the GPM calibration technique are averaged, the calibration accuracy is found to be better than 1 dB.

The above technique has been applied to several BoM operational radars (both S- and C-band) which are located across Australia in different climate regimes. The results show a promising improvement not only in the data quality of radar with relative calibration uncertainty of 0.5 dB or better but also its applicability in better forecasts and warnings of severe and hazardous weather. This poster will present the techniques in brief with their limitations and also the steps to be taken by BoM in order to transition these techniques to operations.