Improving X-Band Weather Radar Calibration By Minimizing Radome Influence through Adaptive FFT Filtering

In recent years, the utility of deployable X-band polarimetric radars in complex terrain has increased due to their smaller size and affordable cost. For ease of transportation, the radome of these radars are generally constructed by joining several panels through metallic threads. In the frame work of the ESPOIRS project, LACy has acquired such an X-band meteorological radar.

In this study, we investigate the effect of the radome joints on the measured polarimetric variables, particularly the differential reflectivity (ZDR) and the differential phase (PHIDP). We observe that the metallic bolts connecting the radome panels cause power loss at certain angles resulting in a bias in ZDR and PHIDP values. To correct for this bias, we have developed a novel algorithm based on Fast Fourier Transform and tested its performance during a heavy rainfall event caused by the Batsirai cyclone in La Reunion Island. The results show that our algorithm is effective in correcting the bias in polarimetric measurements. It will also be applied to other events in order to verify its all-around performance for routine implementation.