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D. Battles (Raytheon, EUMETSAT, Germany), R. Lambeck (Perot Systems, NASA-GSFC),

The Evolution of the Performance of the AVHRR, HIRS and AMSU-S Instruments on board MetOp -A after over Three Years in Orbit. D. Battles (Raytheon, EUMETSAT, Germany), R. Lambeck (Perot Systems, NASA-GSFC), P. Albinana (EUMETSAT, Germany) M. K. Rama Varma Raja (IMSG, NOAA/NESDIS/STAR)

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D. Battles (Raytheon, EUMETSAT, Germany), R. Lambeck (Perot Systems, NASA-GSFC),

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  1. The Evolution of the Performance of the AVHRR, HIRS and AMSU-S Instruments on board MetOp-A after over Three Years in Orbit D. Battles (Raytheon, EUMETSAT, Germany), R. Lambeck (Perot Systems, NASA-GSFC), P. Albinana (EUMETSAT, Germany) M. K. Rama Varma Raja (IMSG, NOAA/NESDIS/STAR) X. Wu (NOAA/NESDIS/STAR) C. Cao (NOAA/NESDIS/STAR) H. Bauch (VEGA Deutschland, GmbH, EUMETSAT, Germany) F. Montagner (EUMETSAT, Germany) NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  2. Scope of this presentation • Focus on NOAA instruments on METOP-A • AVHRR, HIRS, AMSU-A1, and AMSU-A2. • Operational status • Evolution of performances since launch • Few slides on AVHRR Ch3B-IASI comparisons to fit the session because it is “Science Session” NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  3. NOAA Instruments covered in this talk NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  4. AVHRR SPEC • Daily averages monitored • SNR mostly stable. Ch2 shows decreasing trend but well above SPEC • NEdT for all 3 channels do not show any trend and well below SPEC • No seasonality in noise estimates NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  5. AVHRR • Patch Temperature is well controlled (close to 105 K) • Patch power variation does not impact the temperature control • Scan motor current behavior as expected NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  6. HIRS Noise statistics for the period December 2006-June 2010 NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  7. HIRS • Noise are mostly stable • The small trends of SWIR channels (13-19) are expected (ref. C. Cao) and within SPEC • No seasonality in noise estimates NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  8. HIRS • Patch Temperature has been maintained close 94.5 K since launch (excellent passive cooler) • Motor currents are very stable NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  9. AMSU-A • Most of the channels normal except channel 7 • Channel 2 spike attributed to lunar contamination • There is slight trend in channel 3 but well below SPEC NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  10. AMSU-A NEdT started increasing in mid 2008, violated SPEC in December 2008 Declared failed in late 2009. Linked to Warm count rise and gain decrease. Possible cause degradation in mixer/IF amplifier in channel 7 circuit. NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  11. AMSU-A NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  12. AMSU-A NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  13. SUMMARY • All three instruments, AVHRR, HIRS, AMSU-A on MetOp-A are performing very well in orbit outperforming the noise SPEC except for Channel 7 of AMSU-A1. • Trending results confirm excellent long term performance of AVHRR, HIRS and AMSU-A instruments on MetOp-A. • No distinguishable effect of seasonality has been noted NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  14. MetOp-AAVHRR Ch3B comparison with IASI Rama, Fred, Fangfang

  15. IASI coverage

  16. Methodology • Produce Simulated AVHRR channel radiance using IASI hyper-spectral observations and AVHRR spectral response function: Where φ is AVHRR spectral response function interpolated to IASI wave number within the band R is IASI radiance ν is the wave number • Apply necessary quality control and do comparisons

  17. CRTM Simulated IASI spectra covering the entire AVHRR SRF bandwidth Modeled Spectra • Atmospheric absorption (presumably from CO2 predominantly) on Metop-A AVHRR Ch3B SRF. • IASI spectra cover only the strongest part of the AVHRR spectral band and missing the absorption part • Therefore it is possible that partially covered IASI is hotter than AVHRR because IASI missed the colder part

  18. The AVHRR minus IASI negative bias observed in Ch3B can be explained due to the missing part of the IASI spectra over AVHRR spectral band. • Through CRTM simulations it is shown that once this is accounted for the resulting bias can be negligible in this channel 3B • AVHRR Ch3B experiences significant absorption

  19. BACKUP SLIDES

  20. AVHRR Noise statistics for the period December 2006-June 2010 NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  21. AMSU-A NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

  22. AVHRR NOAA/NESDIS/STAR CalPoP Meeting, 08/16/2010

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