Validation of AMSR Rainfall Using an Airborne Precipitation Radar (PR-2)

PI: Eastwood Im
Institution: Jet Propulsion Laboratory
4800 Oak Grove Drive
MS 300-227
Pasadena, CA 91109
Phone: (818) 354-0492
FAX: (818) 354-0492

Co-investigator: Stephen L. Durden, Jet Propulsion Laboratory


NASA EOS-PSO funding through FY02: $120,724


The EOS Aqua will carry the AMSR radiometer, which will produce rainfall as one of its key products. Validation of the rainfall product will involve both ground truth and physical validation approaches, and as part of the validation effort, field experiments will be performed.
We propose to acquire dual-frequency radar measurements of rainfall parameters using our Second-Generation Precipitation Radar (PR-2) airborne instrument for validating and improving the AMSR retrieved rainfall products.

The designed PR-2 observations include vertical structure of rain reflectivity at two frequencies (14 and 35 GHz) and at both co-polarization and cross-polarization, as well as the vertical Doppler measurements. The vertical profiling measurements will be obtained at 37-m resolution. Such comprehensive set of high-resolution radar observables is intended to provide critical information on the vertical distributions of hydrometeor fall rate, drop size distribution, and vertical motion, as well as information on the location of the melting layer, rain regime (e.g. stratiform vs. convective) and hydrometeor type (e.g., ice vs. rain) classifications. The availability of such information set will help to validate and improve the AMSRÕs rain data products, and to enable detailed studies of the microphysics and dynamics of rainfall systems in general.

The specific plan in our proposed research are:

acquire airborne dual-frequency, dual-polarization, Doppler data in rainfall in early 2003,

provide quality control and calibration,

deliver the PR-2 data set for archival,

perform analyses of the PR-2 acquired data and use the results to quantify the uncertainties in the AMSR rainfall retrieval.