Journal article
Estimation of radar-rainfall error spatial correlation
Advances in water resources, Vol.32(7), pp.1020-1030
2009
DOI: 10.1016/j.advwatres.2008.08.014
Abstract
The study presents a theoretical framework for estimating the radar-rainfall error spatial correlation (ESC) using data from relatively dense rain gauge networks. The error is defined as the difference between the radar estimate and the corresponding true areal rainfall. The method is analogous to the error variance separation that corrects the error variance of a radar-rainfall product for gauge representativeness errors. The study demonstrates the necessity to consider the area–point uncertainties while estimating the spatial correlation structure in the radar-rainfall errors. To validate the method, the authors conduct a Monte Carlo simulation experiment with synthetic fields with known error spatial correlation structure. These tests reveal that the proposed method, which accounts for the area–point distortions in the estimation of radar-rainfall ESC, performs very effectively. The authors then apply the method to estimate the ESC of the National Weather Service’s standard hourly radar-rainfall products, known as digital precipitation arrays (DPA). Data from the Oklahoma Micronet rain gauge network (with the grid step of about 5
km) are used as the ground reference for the DPAs. This application shows that the radar-rainfall errors are spatially correlated with a correlation distance of about 20
km. The results also demonstrate that the spatial correlations of radar–gauge differences are considerably underestimated, especially at small distances, as the area–point uncertainties are ignored.
Details
- Title: Subtitle
- Estimation of radar-rainfall error spatial correlation
- Creators
- Pradeep V Mandapaka - IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, IA 52242, USAWitold F Krajewski - IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, IA 52242, USAGrzegorz J Ciach - IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, IA 52242, USAGabriele Villarini - IIHR-Hydroscience & Engineering, The University of Iowa, Iowa City, IA 52242, USAJames A Smith - Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, USA
- Resource Type
- Journal article
- Publication Details
- Advances in water resources, Vol.32(7), pp.1020-1030
- Publisher
- Elsevier Ltd
- DOI
- 10.1016/j.advwatres.2008.08.014
- ISSN
- 0309-1708
- eISSN
- 1872-9657
- Grant note
- DOI: 10.13039/100000104, name: National Aeronautics and Space Administration, award: NNX06AF23H; DOI: 10.13039/100000001, name: National Science Foundation, award: EAR-0309644, EAR-0409501, EAR-0409738
- Language
- English
- Date published
- 2009
- Academic Unit
- Civil and Environmental Engineering
- Record Identifier
- 9983991973102771
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