Calibration of VU C-band polarimetric radar

The Valparaiso University Department of Geography and Meteorology maintains a simultaneous dual-polarization 5-cm Doppler radar, radiosonde system and instrumented meteorological tower. The location near the south end of Lake Michigan allows the observation of very different types of severe weather (lake effect snow, thunderstorms, tornadoes, etc).

Accurate measurements of rainfall rates and correct hydrometeor classification with dual polarimetric radars are only possible if the radar is well calibrated and the quality of the data is verified.

We will show here how we addressed some of these issues, in particular the calibration of reflectivity and differential reflectivity.

Differential reflectivity is calibrated using measurements at vertical incidence. Then reflectivity is calibrated using self consistency method, i.e., making use of the redundancy in the polarimetric variables (Z, ZDR and KDP).

Comparisons of this calibration with nearby NEXRAD radars will be shown.