An Iterative Filtering Technique for the Analysis of Copolar Differential Phase and Dual-Frequency Radar Measurements

Hubbert, J.; Bringi, V. N.

doi:10.1175/1520-0426(1995)012<0643:aiftft>2.0.co;2

Cited by 190 publications

(178 citation statements)

References 0 publications

Supporting

Mentioning

175

Contrasting

Unclassified

Order By: Relevance

“…(4a), (4b), and (4c) respectively for the event considered here), the expressions in (A5), (A7) and (A9) can be used to derive the first estimate of the F dp range profile. Note, these equations rely on accurate K dp estimates from the measured F dp range profile; a suitable smoothing and/or filtering procedure is the iterative FIR method described in Hubbert and Bringi (1995). Figure A1(a) shows an example of the comparison between the measured, and the estimated, F dp range profiles for two cases, (i) for C h ¼ 0 dB (i.e., no calibration error in the measured Z h ) and (ii) for C h ¼ 2 dB (i.e., 2 dB calibration error in the measured Z h ).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Rainfall Estimation from C-Band Polarimetric Radar in Okinawa, Japan: Comparisons with 2D-Video Disdrometer and 400 MHz Wind Profiler

Bringi

Thurai

Nakagawa

et al. 2006

Journal of the Meteorological Society of Japan

View full text Add to dashboard Cite

This paper presents an inter-comparison of rainfall parameters (median volume diameter and rain rate) using C-band polarimetric radar, a 2D-video disdrometer and a 400 MHz profiler for the Baiu front event of 8-9 June 2005 in Okinawa, Japan. These instruments are part of the Okinawa Sub-Tropical Environment Remote Sensing Center, operated by the National Institute of Information and Communications Technology (NICT). The 2D-video disdrometer is used to derive the mean axis ratio of raindrops versus drop diameter, as well as the drop size distribution for the Baiu event. The data are then used to simulate various relations between polarimetric scattering parameters such as: specific attenuation ðA h Þ, and specific differential attenuation ðA dp Þ, versus specific differential phase ðK dp Þ which are required to correct the measured reflectivity at horizontal polarization ðZ h Þ, and the differential reflectivity ðZ dr Þ for rain attenuation. The 2D-video disdrometer data are also used to arrive at retrieval formulas for median volume diameter ðD o Þ from radar Z dr , and rain rate from radar K dp .The These inter-comparisons demonstrate the accuracy of C-band polarimetric radar to retrieve important rainfall parameters, as well as the accurate correction for rain attenuation using differential propagation phase.

show abstract

Section: Discussionmentioning

confidence: 99%

“…The method utilizes the range profile of K dp , derived using the iterative filtering method of Hubbert and Bringi (1995). The correction is done gateby-gate, for both Z h and Z dr as described in the Appendix.…”

Section: Overview Of Radar Measurementsmentioning

confidence: 99%

Rainfall Estimation from C-Band Polarimetric Radar in Okinawa, Japan: Comparisons with 2D-Video Disdrometer and 400 MHz Wind Profiler

Bringi

Thurai

Nakagawa

et al. 2006

Journal of the Meteorological Society of Japan

View full text Add to dashboard Cite

show abstract

“…Several methods were available for use, such as a moving average, median filters, and linear programming approaches. In this study, we used the finite impulse response (FIR) filter based on Hubbert and Bringi (1995). Once the filtered PhiDP profile was obtained, KDP was calculated using a least squares linear fit.…”

Section: Methodsmentioning

confidence: 99%

Overview: Precipitation characteristics and sensitivities to environmental conditions during GoAmazon2014/5 and ACRIDICON-CHUVA

et al. 2018

View full text Add to dashboard Cite

Abstract. This study provides an overview of precipitation processes and their sensitivities to environmental conditions in the Central Amazon Basin near Manaus during the GoAmazon2014/5 and ACRIDICON-CHUVA experiments. This study takes advantage of the numerous measurement platforms and instrument systems operating during both campaigns to sample cloud structure and environmental conditions during 2014 and 2015; the rainfall variability among seasons, aerosol loading, land surface type, and topography has been carefully characterized using these data. Differences between the wet and dry seasons were examined from a variety of perspectives. The rainfall rates distribution, total amount of rainfall, and raindrop size distribution (the massweighted mean diameter) were quantified over both seasons.The dry season generally exhibited higher rainfall rates than the wet season and included more intense rainfall periods. However, the cumulative rainfall during the wet season was 4 times greater than that during the total dry season rainfall, as shown in the total rainfall accumulation data. The typical size and life cycle of Amazon cloud clusters (observed by satellite) and rain cells (observed by radar) were examined, as were differences in these systems between the seasons. Moreover, monthly mean thermodynamic and dynamic variables were analysed using radiosondes to elucidate the differences in rainfall characteristics during the wet and dry seasons. The sensitivity of rainfall to atmospheric aerosol loading was discussed with regard to mass-weighted mean diameter and rain rate. This topic was evaluated only durPublished by Copernicus Publications on behalf of the European Geosciences Union. L. A. T. Machado et al.: Overview: Precipitation characteristics and sensitivities to environmental conditionsing the wet season due to the insignificant statistics of rainfall events for different aerosol loading ranges and the low frequency of precipitation events during the dry season. The impacts of aerosols on cloud droplet diameter varied based on droplet size. For the wet season, we observed no dependence between land surface type and rain rate. However, during the dry season, urban areas exhibited the largest rainfall rate tail distribution, and deforested regions exhibited the lowest mean rainfall rate. Airplane measurements were taken to characterize and contrast cloud microphysical properties and processes over forested and deforested regions. Vertical motion was not correlated with cloud droplet sizes, but cloud droplet concentration correlated linearly with vertical motion. Clouds over forested areas contained larger droplets than clouds over pastures at all altitudes. Finally, the connections between topography and rain rate were evaluated, with higher rainfall rates identified at higher elevations during the dry season.

show abstract

“…Hubbert and Bringi, 1995;Wang and Chandrasekar, 2009). To evaluate qualitatively the impact of the length of the filter in our simple algorithm, a numerical model was developed.…”

Section: Differential Reflectivity (Z Dr )mentioning

confidence: 99%

Long‐term monitoring of French polarimetric radar data quality and evaluation of several polarimetric quantitative precipitation estimators in ideal conditions for operational implementation at C‐band

Ventura

Boumahmoud

Fradon

et al. 2012

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

This article presents the evaluation of several polarimetric quantitative precipitation estimation (Pol-QPE) algorithm candidates for operational implementation in the Météo-France polarimetric weather radars (nine C-band and one S-band out of a total of 24 radars in 2011). Since the performance of the algorithms depends on both the quality of the polarimetric variables and the applied polarimetric processing, the article first describes the current polarimetric processing chain and then provides a comprehensive analysis of the quality of the polarimetric variables.Three types of QPE algorithms have been studied at C-band in ideal conditions (short ranges, no partial beam blocking, no vertical profile of reflectivity effects): (i) algorithms based on simple Z-R relationships with and without attenuation correction using the differential phase dp , (ii) an algorithm based on reflectivity (Z h ) and differential reflectivity (Z dr ), and (iii) algorithms based on specific differential phase (K dp ).Evaluation against rain-gauges, performed hourly, confirms the superiority of polarimetric algorithms as repeatedly reported in the literature. It also shows that the benefits brought by algorithms based on power variables, Z h and Z dr , are critically dependent upon the capability to correctly calibrate them. Long-term monitoring shows that, with the current radar systems and operational calibration procedures, a stability of ±0.4 dB is achieved on Z dr . In that context, QPE algorithms based on K dp , which are considered to be immune to partial beam blocking, calibration, attenuation, etc., are preferred for operational use until improvements are made to the calibration of Z dr . To this end, a hybrid algorithm based on attenuationcorrected Z h for low rain rates and K dp for higher rain rates has been designed and tested Copyright c 2012 Royal Meteorological Society Key Words: polarimetry; polarimetric processing; radar calibration; radar-raingauge comparisons

show abstract

An Iterative Filtering Technique for the Analysis of Copolar Differential Phase and Dual-Frequency Radar Measurements

Cited by 190 publications

References 0 publications

Rainfall Estimation from C-Band Polarimetric Radar in Okinawa, Japan: Comparisons with 2D-Video Disdrometer and 400 MHz Wind Profiler

Rainfall Estimation from C-Band Polarimetric Radar in Okinawa, Japan: Comparisons with 2D-Video Disdrometer and 400 MHz Wind Profiler

Overview: Precipitation characteristics and sensitivities to environmental conditions during GoAmazon2014/5 and ACRIDICON-CHUVA

Long‐term monitoring of French polarimetric radar data quality and evaluation of several polarimetric quantitative precipitation estimators in ideal conditions for operational implementation at C‐band

Contact Info

Product

Resources

About