Partial Beam Blockage Correction Using Dual-Polarimetric Measurements

A new method that directly uses measured total differential phase along a radar beam as a constraint to estimate the fractional beam blockage is presented. It takes advantage of the differential phase immunity to partial beam blockage. The algorithm is applied to dual-polarimetric radar data collected during the SoWMEX/TiMREX experiment in June 2008 in Taiwan with the NCAR's radar. Corrected reflectivity factor in the blocked area is compared with values deduced from a Digital Elevation Map (DEM) to show the advantage over DEM in areas where obstacle such as high rising buildings are located along the radar beams. The accuracy and steadiness of the new method is quantitatively evaluated using a series of radar volume scans obtained in three rainfall events.