1. GPM GMI update Chris Kidd

2. RFI issues Two main sources: Reflection from broadcast satellites - affects 18.7 GHz primarily to varying degrees - can be predicted to some extent Surface emissions - spurious emissions from surface emitters - affects primarily 6.9 and 10.7 GHz, but also 18.7GHz

4. 20140305 -S061920 V10 H10 V18 H18 secondary RFI – sidelobe/2 nd satellite Strong RFI over ice

5. 20140307 -S060554 V10 H10 V18 H18 Strong RFI from ice (?)

6. 20140309 -S0055206 V10 H10 V18 H18 subtle RFI – H channel only

7. Broadcast RFI Ice appears to provide a very good reflector of 18.7 GHz RFI (ice structure?) Water surfaces more variable – presumably due to wave orientation Some land surfaces also reflect – more subtle Possible to forward-calculate satellite-surface- satellite path to identify regions of possible RFI Obvious RFI is good – subtle RFI is bad.

8. Surface RFI Primarily at 10GHz Initial study by the Office of Communication, Ofcom, (UK), found that at 10.67 GHz licenses had been issued within ITC regulations (low-power (mW) motion detection systems). 18 GHz sources Some broadcast bands, but usually satellite-ground, occasionally associated with ship-based radars. Mobile phones are <3 GHz, possibly communication links at 18 GHz (Spanish?).

9. V10 H10 V18 H18 20140308 -S234218

10. V10 H10 V18 H18 20140309 -S224904

11. 20140309 -S224904 V18 Kartoum El Obeid Abu Zabad Shendi Wad Medani Atbara

12. GMI quicklook images: Daily global asc/desc image TRMM false-colour scheme 1/8 degree resolution (2880x1440) ftp://meso-a.gsfc.nasa.gov/kidd/GMIql

13. quick-look_GMI_20140517_dsc.jpg

14. 16 May 2014

15. SSMIS F16 15:00 GMI 15:30 Radar 15:30 MHS N18 16:00 MHS N18 MSPPS 16:00 SSMIS F17 16:00 Precip retrievals 7 April 2014

16. Constellation x-track – ideal (!)

17. My Best Guess as of 5/9/14 GMI Calibration Error over Ocean Standard 10V3.0KWindsat 10H1.6K " 18V2.5K " 18H0.0K " 23V0.2K " 36V-1.3K " 36H-1.3K " 89V 3.8KMetop A or B 89H 4.2K " 166V-3.4K " 166H-1.4K " ±3--2.0K " ±7-2.9K " Tom Wilheit 2014

18. GMI vs TMI GMI - TMI double differences Ver 10v 10h 18v 18h 23v 36v 36h 89v 89h --- --- --- --- --- --- --- --- --- --- V01D 4.3 3.1 3.3 2.7 1.9 2.3 1.2 1.0 1.0 V02A 4.2 3.2 3.1 2.8 1.7 2.1 1.2 0.8 0.9 Rachael Kroodsma (NASA PPS)

19. Solar intrusion (V) Tom Wilheit 2014

20. Solar intrusion (H) Tom Wilheit 2014

21. Additional slides…

24. 20140308 -S051249 V10 H10 V18 H18 Strong RFI not ice (?)

25. 20140311 -S040553 V10 H10 V18 H18 Very subtle RFI – V&H channel

26. Kidd, 2006

29. 20140310 -S045852 V10 H10 V18 H18 Strong RFI from ice (?)