1. An SSM/I - SSMI/S Application for Climate Research: the Extension of Hydrological Products Climate Records
Daniel Vila – R. Ferraro – J. Turk – F. Weng
Cooperative Institute for Climate Studies
University of Maryland

2. OUTLINES Introduction – SSMI-based Monthly Hydrological Products
SSMI – SSMIS similarities and differences.
Intercomparison strategy: the Simultaneous Conical Overpass (SCO) approach
Validation results for Rainfall Rate (RR)
Can we extend application to F17?
Beacon interference in DMSP F15 22V: evaluation of a correction scheme

3. SSMI-based Monthly Hydrological Products
Global monthly rainfall estimates (RR) and other hydrological products like integrated Cloud Liquid Water (CLW) and Total Precipitable Water (TPW) have been produced from 1987 to present using measurements from the Defense Meteorological Satellite Program (DMSP) series of Special Sensor Microwave Imager (SSM/I)
Ferraro, 1997
Weng and Grody, 1994
Alihouse et al., 1990

4. SSMI – SSMIS similarities and differences

5. SSMI – SSMIS similarities and differences
Comparison of SSMI and SSMI/S Sensors characteristics for those specific channels used in the hydrological product generation

6. Image courtesy of Eric Nelkin, NASA/GSFC
SSMI – SSMIS similarities and differences
F13 – Sensor degradation?
F14 – Recorders have failed
F15 - RADCAL
F17 – Replacement for F13
F16 – Replacement for F14/F15
Image courtesy of Eric Nelkin, NASA/GSFC

7. How to continue with the Climate Data Records?

8. Simultaneous Conical Overpass (SCO) approach
A Simultaneous Conical Overpass (SCO) is defined as the data pair generated when two polar-orbiting satellites (SSM/I F15 and SSMI/S F16 cross the same area at similar local times (t < 7 minutes).

9. Simultaneous Conical Overpass (SCO) approach
Develop empirical fits between SSM/I F15 and SSMI/S F16 during period of close overpass times (3/06 – 2/07)
All channels
Stratify via land/ocean; rain/no-rain
RADCAL correction applied to F15 8/06 and forward
Improves
Rain/No-Rain threshold
Rain rate PDF’s
Other products (e.g., TPW, CLW, etc.)
Can be extended to F17 as well, although procedure should be duplicated

11. Scattering Index (SI)
Simultaneous Conical Overpass (SCO) approach
Uncorrected

12. Scattering Index (SI)
Simultaneous Conical Overpass (SCO) approach
Uncorrected
Corrected

13. SSMI/S F16 - Uncorrected
April 2008
SSMI/S F16 - Corrected

14. SSMI F15
April 2008
SSMI/S F16 - Corrected

15. Validation results
Ocean
Land
Uncorrected
Corrected

16. Validation results

19. Image courtesy of Eric Nelkin, NASA/GSFC
SSMI – SSMIS similarities and differences
F13 – Sensor degradation?
F14 – Recorders have failed
F15 - RADCAL
F17 – Replacement for F13
F16 – Replacement for F14/F15
Image courtesy of Eric Nelkin, NASA/GSFC

21. Thanks!