1. Liang Liao Goddard Earth Sciences & Technology Research Morgan State University Greenbelt, MD 20771 Robert Meneghini NASA/Goddard Space Flight Center Greenbelt, MD 20771 Evaluation of TRMM Precipitation Radar for Estimates of Surface Rainfall Rate

2. Objectives IGARSS 2011 Vancouver Validating TRMM PR Measurements –Compare with the well-calibrated non- attenuated ground-based radar measurements. Examining TRMM PR Algorithms –Rain attenuation correction –Rain rate estimation –Version-7 vs. Version-6

3. IGARSS 2011 Vancouver WSR-88D Ground-Based Radar

4. IGARSS 2011 Vancouver Earth Coordinate System Schematic diagram of the earth coordinate system in which the latitude, , and longitude,, are defined.

5. IGARSS 2011 Vancouver Geometry for correction of PR offsets (  x and  y) in x and y axes at a height of h.

6. IGARSS 2011 Vancouver Radar Measurements (3/9/1998)

7. IGARSS 2011 Vancouver PR vs. WSR-88D in Melborne

8. IGARSS 2011 Vancouver Radar Reflectivity (3/9/1998) h = 1.5 km h = 3 km

9. IGARSS 2011 Vancouver Radar Reflectivity at h=7.5 (1998-2007)

10. IGARSS 2011 Vancouver Radar Reflectivity at h=1.5 (1998-2007)

11. IGARSS 2011 Vancouver Scatter Plots of Mean Reflectivity (h=3 km)

12. IGARSS 2011 Vancouver Scatter Plots of Rain (1998-2007)

13. IGARSS 2011 Vancouver Scatter Plots of Mean Rain (1998-2007)

14. IGARSS 2011 Vancouver Area-Averaged Rain WSR-88D TRMM PR

15. IGARSS 2011 Vancouver Area-Averaged Rain (1998-2007)

16. IGARSS 2011 Vancouver Scatter Plots of Mean Reflectivity (2008-2009) PR (v6) vs. WSR-88D at a height of 3.0 km in MELB PR (v7) vs. WSR-88D at a height of 3.0 km in MELB

17. IGARSS 2011 Vancouver Scatter Plots of Mean Rain (2008-2009) PR (v6) vs. WSR-88D in MELB PR (v7) vs. WSR-88D in MELB

18. IGARSS 2011 Vancouver Relative Biases (2008-2009)

19. IGARSS 2011 Vancouver Relative Bias (2008-2009)

20. Comparisons of the PR-derived reflectivities and rain rates with the same quantities derived from near-simultaneous measurements by the WSR-88D ground-based Melbourne radar are presented for more than 230 overpasses during 1998-2007. The reflectivity fields derived from the PR data after attenuation correction, and the conditional mean and area- averaged rain rates from the PR agree well with those obtained from the WSR-88D. Improvement of rain estimates is found from PR version-6 to version-7 standard products. Further comparisons will be conducted in the future as more data become available and these procedures will be extended to the other climatological sites. Summary IGARSS 2011 Vancouver