An Easy-to-Use Software Tool for Quantifying Calibration Errors and Partial Beam Blockage from Operational Radar Reflectivity and Specific Phase Shift Measurements

Knowledge of biases in radar reflectivity measurements which can be caused by calibration errors and partial beam blockage (PBB) is crucial for numerous applications in weather radar meteorology. Various methods for estimating these error sources exist, involving digital elevation models (DEM) or comparisons with ground measurements or other radar systems. We present a simple software tool programmed in Interactive Data Language (IDL) that can be used to estimate calibration and PBB-related biases within 1 to 2 dB precision from operational weather radar scans. No additional measurements except several days of weather radar data during rainfall of medium intensity are required. The tool has been tested on 3 X-Band and 2 C-Band radar systems, and precision of re-calibration and PBB estimation is verified with independent DEM, radar, and rain gauge measurements.