HR: 0800h
AN: H21E-0807    [Abstracts]
TI: On the Remapping of Radar Estimates onto Cartesian Coordinates
AU: * Sharif, H
EM: hatim.sharif@utsa.edu
AF: UNiversity of Texas, One UTSA Circle, San Antonio, TX 78249,
AU: Ogden, F
EM: fogden@uwyo.edu
AF: University of Wyoming, Department of Civil & Architectural Engineering, Laramie, WY 82072,
AB: A precise method for remapping of radar estimates onto Cartesian grids of different sizes was introduced. The method is straightforward and the algorithm developed for this study can be used to perform averaging over grids of any size or shape. Comparison of rainfall estimates using this method and estimates computed using a simple averaging method typically used by hydrologists reveals that there can be significant differences. Differences are expected to be much larger if precise remapping is compared to simpler methods such as the nearest neighbor. The method is particularly useful if products from more that one radar are to be merged. Using this method it is not necessary to interpolate estimates from two radars over Cartesian grid before merging is performed. In addition, gauge-radar comparisons and bias computation can be more consistent when precise remapping is used. Another advantage of precise remapping is that it will be very easy to account for the variability of the power within the radar bin using this scheme because the contribution from each radar bin is defined geometrically in a precise way. Grids constructed this way are the closest representation of radar observation of the atmosphere in Cartesian coordinates. The same approach was used to remap rainfall estimates from one radar onto the bin of another radar of lower resolution. Precise remapping was used in comparing estimates of the higher-resolution NCAR's S-band radar (S-Pol) and a WSR-88D radar. Detailed comparison of fields of instantaneous rain rate reveals that the correlation between the estimates of the two systems varies spatially. The correlation is highest at the mid-point between the two radars and decreases with distance from this point.
DE: 1853 Precipitation-radar
DE: 1854 Precipitation (3354)
SC: Hydrology [H]
MN: 2007 Fall Meeting