Adaptive Attenuation Correction Techniques for C-Band Polarimetric Weather Radars

Rico‐Ramirez, Miguel A.

doi:10.1109/tgrs.2012.2195228

Cited by 24 publications

(7 citation statements)

References 43 publications

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“…The DRPA method has been improved through being less affected by the bias of reflectivity and differential reflectivity [8]. RicoRamirez (2012) extended HB and Iguchi's "Final Value" (FV) [9] algorithms to make the correction coefficients adaptive by parameter optimization in a similar way to the SC method [10]. Kalogiros et al (2014) provided the self-consistent with optimal parameterization (SCOP) algorithm for attenuation correction of radar reflectivity which uses optimal parameterization and best-fitted functions of specific attenuation and backscattering differential phase shift [11].…”

Section: Introductionmentioning

confidence: 99%

Attenuation Correction of Weather Radar Reflectivity with Arbitrary Oriented Microwave Link

Zhang

Liu

et al. 2017

Advances in Meteorology

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To compensate radar reflectivity for attenuation effect, a new method for attenuation correction of the radar reflectivity using arbitrary oriented microwave link (referred henceforth to as ACML) is developed and evaluated. Referring to the measurement of arbitrary oriented microwave link, the ACML method optimizes the ratio of specific attenuation to specific differential phase which is a key parameter in attenuation correction schemes. The proposed method was evaluated using real data of a dual-polarization X-band radar and measurements of two microwave links during two rainstorm events. The results showed that the variation range of the optimized ratio was overall consistent with the results of the previous studies. After attenuation correction with the optimal ratios, the radar reflectivity was significantly compensated, especially at long distances. The corrected reflectivity was more intense than the reflectivity corrected by the "self-consistent" (SC) method and closer to the reflectivity of a nearby S-band radar. The effectiveness of the method was also verified by comparing the rain rates estimated by the X-band radar with those derived by rain gauges. It is demonstrated that arbitrary oriented microwave link can be adopted to optimize the attenuation correction of radar reflectivity.

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Section: Introductionmentioning

confidence: 99%

Attenuation Correction of Weather Radar Reflectivity with Arbitrary Oriented Microwave Link

Zhang

Liu

et al. 2017

Advances in Meteorology

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“…It is fair to say that the Met Office is currently upgrading all weather radars in the UK to dual‐polarization weather radars. This will enable better identification of nonmeteorological echoes (Rico‐Ramirez & Cluckie, ), improvements of attenuation correction algorithms (Bringi et al, ; Rico‐Ramirez, ), and better rainfall estimates in the presence of partial beam blockage (Lang et al, ). The SA method could be more effective in the absence of these weather radar artifacts.…”

Section: Discussionmentioning

confidence: 99%

Comparing Approaches to Deal With Non‐Gaussianity of Rainfall Data in Kriging‐Based Radar‐Gauge Rainfall Merging

Cecinati

Wani

Rico‐Ramirez

2017

Water Resources Research

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Merging radar and rain gauge rainfall data is a technique used to improve the quality of spatial rainfall estimates and in particular the use of Kriging with External Drift (KED) is a very effective radar‐rain gauge rainfall merging technique. However, kriging interpolations assume Gaussianity of the process. Rainfall has a strongly skewed, positive, probability distribution, characterized by a discontinuity due to intermittency. In KED rainfall residuals are used, implicitly calculated as the difference between rain gauge data and a linear function of the radar estimates. Rainfall residuals are non‐Gaussian as well. The aim of this work is to evaluate the impact of applying KED to non‐Gaussian rainfall residuals, and to assess the best techniques to improve Gaussianity. We compare Box‐Cox transformations with λ parameters equal to 0.5, 0.25, and 0.1, Box‐Cox with time‐variant optimization of λ, normal score transformation, and a singularity analysis technique. The results suggest that Box‐Cox with λ = 0.1 and the singularity analysis is not suitable for KED. Normal score transformation and Box‐Cox with optimized λ, or λ = 0.25 produce satisfactory results in terms of Gaussianity of the residuals, probability distribution of the merged rainfall products, and rainfall estimate quality, when validated through cross‐validation. However, it is observed that Box‐Cox transformations are strongly dependent on the temporal and spatial variability of rainfall and on the units used for the rainfall intensity. Overall, applying transformations results in a quantitative improvement of the rainfall estimates only if the correct transformations for the specific data set are used.

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“…Radar-based Stage IV shows underestimations of reference rainfall over basins in the Western CONUS (Henn et al 2018). This is because of difficulties in retrieving orographic precipitation due to beam blockage, and signal attenuation in mountainous regions (Bringi et al 2011;Dai et al 2015;Germann et al 2006;Rico-Ramirez 2021;Nanding et al 2015;Rico-Ramirez 2012;Wang et al 2015). The performances of these precipitation products vary between basins due to the strengths and limitations in their measuring devices.…”

Section: Evaluation Of Drive-nldas-2 Simulated Dischargementioning

confidence: 99%

Assessment of Precipitation Error Propagation in Discharge Simulations over the Contiguous United States

Nanding

Tao

et al. 2021

Journal of Hydrometeorology

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This study characterizes precipitation error propagation through a distributed hydrological model based on the river basins across the Contiguous United States (CONUS), to better understand the relationship between errors in precipitation inputs and simulated discharge (i.e., P-Q error relationship). The NLDAS-2 precipitation and its simulated discharge are used as the reference to compare with TMPA-3B42 V7, TMPA-3B42RT V7, StageIV, CPC-U, MERRA-2, and MSWEP-2.2 for 1,548 well gauged river basins. The relative errors in multiple conventional precipitation products and their corresponding discharges are analysed for the period of 2002-2013. The results reveal positive linear P-Q error relationships at annual and monthly timescales, and the stronger linearity for larger temporal accumulations. Precipitation errors can be doubled in simulated annual accumulated discharge. Moreover, precipitation errors are strongly dampened in basins characterized by temperate and continental climate regimes, particularly for peak discharges, showing highly nonlinear relationships. Radar-based precipitation product consistently shows dampening effects on error propagation through discharge simulations at different accumulation timescales compared to the other precipitation products. Although basin size and topography also influence the P-Q error relationship and propagation of precipitation errors, their roles depend largely on precipitation products, seasons and climate regimes.

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Adaptive Attenuation Correction Techniques for C-Band Polarimetric Weather Radars

Cited by 24 publications

References 43 publications

Attenuation Correction of Weather Radar Reflectivity with Arbitrary Oriented Microwave Link

Attenuation Correction of Weather Radar Reflectivity with Arbitrary Oriented Microwave Link

Comparing Approaches to Deal With Non‐Gaussianity of Rainfall Data in Kriging‐Based Radar‐Gauge Rainfall Merging

Assessment of Precipitation Error Propagation in Discharge Simulations over the Contiguous United States

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