Validation of TRMM Precipitation Radar through Comparison of Its Multiyear Measurements with Ground-Based Radar
- 1 April 2009
- journal article
- Published by American Meteorological Society in Journal of Applied Meteorology and Climatology
- Vol. 48 (4), 804-817
- https://doi.org/10.1175/2008jamc1974.1
Abstract
A procedure to accurately resample spaceborne and ground-based radar data is described and then is applied to the measurements taken from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and the ground-based Weather Surveillance Radar-1988 Doppler (WSR-88D or WSR) for the validation of the PR measurements and estimates. Through comparisons with the well-calibrated, nonattenuated WSR at Melbourne, Florida, for the period 1998–2007, the calibration of the PR aboard the TRMM satellite is checked using measurements near the storm top. Analysis of the results indicates that the PR, after taking into account differences in radar reflectivity factors between the PR and WSR, has a small positive bias of 0.8 dB relative to the WSR, implying a soundness of the PR calibration in view of the uncertainties involved in the comparisons. Comparisons between the PR and WSR reflectivities are also made near the surface for evaluation of the attenuation-correction procedures used in the PR algorithms. It is found that the PR attenuation is accurately corrected in stratiform rain but is underestimated in convective rain, particularly in heavy rain. Tests of the PR estimates of rainfall rate are conducted through comparisons in the overlap area between the TRMM overpass and WSR scan. Analyses of the data are made both on a conditional basis, in which the instantaneous rain rates are compared only at those pixels at which both the PR and WSR detect rain, and an unconditional basis, in which the area-averaged rain rates are estimated independently for the PR and WSR. Results of the conditional rain comparisons show that the PR-derived rain is about 9% greater and 19% less than the WSR estimates for stratiform and convective storms, respectively. Overall, the PR tends to underestimate the conditional mean rain rate by 8% for all rain categories, a finding that conforms to the results of the area-averaged rain (unconditional) comparisons.Keywords
This publication has 24 references indexed in Scilit:
- Use of Dual-Wavelength Radar for Snow Parameter EstimatesJournal of Atmospheric and Oceanic Technology, 2005
- Ground Validation for the Tropical Rainfall Measuring Mission (TRMM)Journal of Atmospheric and Oceanic Technology, 2005
- Accuracy verification of spaceborne radar estimates of rain rateAtmospheric Science Letters, 2005
- Uniting Space, Ground, and Underwater Measurements for Improved Estimates of Rain RateIEEE Geoscience and Remote Sensing Letters, 2004
- A Methodology for Estimating the Parameters of a Gamma Raindrop Size Distribution Model from Polarimetric Radar Data: Application to a Squall-Line Event from the TRMM/Brazil CampaignJournal of Atmospheric and Oceanic Technology, 2002
- Development of precipitation radar onboard the Tropical Rainfall Measuring Mission (TRMM) satelliteIEEE Transactions on Geoscience and Remote Sensing, 2001
- Quantitative Cross Validation of Space-Based and Ground-Based Radar ObservationsJournal of Applied Meteorology and Climatology, 2000
- Climatological processing and product development for the TRMM ground validation programPhysics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere, 2000
- The Window Probability Matching Method for Rainfall Measurements with RadarJournal of Applied Meteorology and Climatology, 1994
- ERRORS INHERENT IN THE RADAR MEASUREMENT OF RAINFALL AT ATTENUATING WAVELENGTHSJournal of Meteorology, 1954