System of weather radar volume data (3-D) quality control: RADVOL-QC

RADVOL-QC system is to perform two main tasks in weather radar data processing: (i) the data corrections due to most significant errors and (ii) quantitative characterization of the data quality. This quality control is made on 3-D radar reflectivity volume data. The following algorithms are included in the current version of the data correction component: (i) removal of interfering external antenna echoes, (ii) speckle and reverse speckle elimination, (iii) radar beam blockage correction, and (iv) correction of radar beam attenuation in the precipitation.

Simultaneously to the data correction, the 3-D data quality is quantitatively evaluated. All corrections are connected with estimation of quality decrease due to specific measurement errors. A variety of quality factors is taken into account to estimate final quality of the data, that is expressed as quality index (QI), which is a unitless metric of the data quality.

The quality characterization algorithms employed in RADVOL-QC are based on analyses of: (i) set of technical radar parameters, (ii) effects related to distance to radar site, e.g. height of the lowest radar beam, (iii) ground clutter existence, (iv) geometrically shaped non-meteorological echoes, e.g. from external signals, (v) beam blockage, (vi) attenuation in rain, and (vii) total impact of all introduced corrections.

The example of effectiveness of the system running in terms of both data corrections and quality evaluation on data from Polish weather radar network POLRAD will be presented.