| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 17:46 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2014 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Method of improving the quality of radar reflectivity data
Authors:
S. BURCEA, D. CARBUNARU
Affiliation:
National Meteorological Administration, Bucharest, Romania
E-mail
sorin.burcea@meteoromania.ro
Keywords:
weather radar, reflectivity, data quality, algorithm
Abstract:
While scanning the atmosphere within the radar coverage, both meteorological and non-meteorological targets can be detected. Although effective signal processing techniques for identifying and removing non-meteorological echoes exist, radar measurements can still be contaminated. This situation occurs because of the existence of clutter sources, biological targets, or external electromagnetic interferences within the volume scan. Addressing the issue of data contamination and quality control, this can be regarded as a double task. The first task refers to the detection and removal of contaminated data, while the second is related to the mitigation of the effects of the first task on good data. This research presents a reflectivity quality control method that makes use of the three-dimensional structure of the sampled data, both horizontal and vertical parameters being computed. The method is built on an algorithm that is executed on raw polar radar volumes, to remain at the level of the data recording. The general structure of the algorithm consists of a series of sub-algorithms, each one handling specific processing tasks. The algorithm is built considering several key quality issues, namely, residual ground clutter, anomalous propagation, and external interference echoes. First, reflectivity data are passed through a noise filter in order to identify and remove isolated reflectivity bins. Afterwards, identification and removal of radials contaminated by external signals is performed. Further, the horizontal texture and the vertical gradient of reflectivity are computed to address the anomalous propagation issue.
The algorithm has been tested on data sampled by radars located in various scanning environments (e.g., plain, complex terrain), considering also different seasonal and diurnal times. The algorithm performs well, results showing that non-precipitation echoes are successfully identified and removed. Depending on the characteristics of the scanning environment, fine-tuning the algorithm parameter settings or executing only certain sub-algorithms can improve the final output.
|
|
|
|