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NOAA-19 Multi-Sensor OV Presentation

NOAA-19 Multi-Sensor OV Presentation. Thomas J. Kleespies NOAA/NESDIS/STAR 6 May 2009. Topics. AMSU/MHS pointing/geolocation AMSU A/D test AVHRR/HIRS co-registration AMSU/MHS/HIRS scan bias AMSU RFI?. AM1012/AM2012 NOAA-19 AMSU Geolocation Study. Thomas J. Kleespies. Methodology.

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NOAA-19 Multi-Sensor OV Presentation

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  1. NOAA-19 Multi-Sensor OV Presentation Thomas J. Kleespies NOAA/NESDIS/STAR 6 May 2009

  2. Topics • AMSU/MHS pointing/geolocation • AMSU A/D test • AVHRR/HIRS co-registration • AMSU/MHS/HIRS scan bias • AMSU RFI?

  3. AM1012/AM2012NOAA-19 AMSU Geolocation Study Thomas J. Kleespies

  4. Methodology • Compute synthetic radiances using measured antenna patterns over coastlines – compute correlation with ensemble of observed radiances • Move coastline around and repeat • Construct correlation matrix • Geolocation is correct if center of ellipsoid matches crosshairs at fov center

  5. Layout and Order of Slides 09053 Europe 09054 Europe

  6. Results • AMSU-A2 offset ~5-10 km xtrack left Alongtrack OK • AMSU-A1-2 offset ~15km xtrack Alongtrack OK • AMSU-A1-1 offset ~ 10-15 km xtrack left Alongtrack OK

  7. MHS019NOAA-19 MHS Geolocation Thomas J. Kleespies

  8. Methodology • Compute synthetic radiances using measured antenna patterns over coastlines – compute correlation with ensemble of observed radiances • Move coastline around and repeat • Construct correlation matrix • Geolocation is correct if center of ellipsoid matches crosshairs at fov center

  9. Oceania Ascending Europe Ascending Oceania Descending Europe Descending 09053

  10. Oceania Ascending Europe Ascending Oceania Descending Europe Descending 09054

  11. Result • Offset is apparent that is in the opposite sense for ascending and descending portions of the orbit. • It appears that the pointing/geolocation is off by 3-5 km along and cross track. • (to the right and uptrack)

  12. HIR022AVHRR-HIRS Co-Registration Thomas J. Kleespies

  13. Methodology • Use 1B reported center of HIRS fov. • Find AVHRR GAC pixels within HIRS fov and average A4 • Do this for a GAC orbit • Compute correlation between AVHRR and HIRS radiances • Move the center GAC pixel one by one along track and cross track • Construct cross correlation matrix

  14. + NSS.GHRR.NP.D09078.S1126.E1313.B0057879.GC NSS.HIRX.NP.D09078.S1126.E1313.B0057879.GC Looks like co-registration is one GAC pixel off. Need to repeat for LAC. Pascal Brunel (METEOFRANCE) reports a couple of HRPT pixels off

  15. AMSU-A Analog/Digital Converter Thomas J. Kleespies

  16. 09039-09057

  17. Spikes in histogram at 16 count intervals

  18. NOAA-19/18 AMSU-A Asymmetry09042-09049 Ocean 40N-40S Precipitation Screened Thomas J. Kleespies AM1014-AM2014

  19. Methodology • Feb 11-17 • Earth scene antenna temperatures binned as function of scan position • 40N – 40S • Ocean only (avoiding coastlines as well) • Precipitation screening using Grody Algorithm • Mean brightness temperatures differenced pairwise left – right • Ascending: solid line, descending: dashed line

  20. N19 Mean Antenna Temperature Difference (left – right)

  21. N18 Mean Antenna Temperature Difference (left – right)

  22. Conclusions • A2 seems to have ascending/descending disparity • Ch 15 (A1-1) bias opposite sense than other windows • Sounding channels ascending/descending behavior fairly consistent • Window channels behave in opposite sense N19/N18

  23. NOAA-19 MHS Asymmetry09044-09048 Ocean 40N-40S Precipitation Screened Thomas J. Kleespies MHS018

  24. Methodology • Feb 11-17 • Earth scene brightness temperatures binned as function of scan position • 40N – 40S • Ocean only (avoiding coastlines as well) • Precipitation screening using Grody Algorithm • Mean brightness temperatures differenced pairwise left – right • Ascending: solid line, descending: dashed line

  25. Mean Antenna Temperature

  26. Mean Antenna Temperature Difference (left – right)

  27. Conclusions • Window channels: descending (nighttime) node warmer than ascending (daytime) node (diurnal temperature variation should be the other way around) • Sounding channels show a slight bias (few tenth degree) with the right side being warmer

  28. HIR023 Scan Bias Comparison N19 and Metop-A and N17 09058-09067 Thomas J. Kleespies

  29. Conclusions • Longwave channels have scan dependent spikey biases. This is especially true of cold channels • Periodicity of spikeness different for N19, M2, N17 • Left side warmer than right side by > 1K, mostly in cold channels

  30. NOAA 19 AMSU-A RFI? Thomas J. Kleespies

  31. Methodology • Space look antenna temperatures 30 days 09051-09090 • Flagged when space look Ta > 4 sigma from orbital mean • + = gt +4 sigma from mean: - = lt -4 sigma • ^ ascending v descending • Plotted at the spacecraft subpoint when event happened

  32. I’m Looking for Ideas Here • These patterns only appear when examining about a month of data in bulk • Channels 4,5,6 have a pattern that is distinctly not natural. • RFI from Geosynch? At 50+GHz? • How can RFI cause space to appear colder than the orbital mean? • This also seen in all other SC excepting Metop and Aqua

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