NOAA18 Instrument Calibration and Validation Briefing

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NOAA-18 Instrument Calibration and Validation
Briefing

• NOAA/NESDIS/Office of Research and Applications
• As of the Week of July 18, 2005
• For archived activities and latest news, please
  visit
• http//www.orbit.nesdis.noaa.gov/smcd/spb/n18calva
  l

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Weekly Highlights (July 18-22)

• HIRS Intersatellite Calibration
• SNO results using NOAA-17 and 18 HIRS data
• AMSU Cal/Val
• Test of three AMSU antenna pattern correction
  schemes and identify an optimal one

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NOAA-18 Instrument Payload
We focus on these instruments

• AVHRR/3 Advanced Very High Resolution Radiometer
• HIRS/4 High Resolution Infrared Sounder
• AMSU-A Advanced Microwave Sounding Unit-A
• MHS Microwave Humidity Sounder
• SBUV/2 Solar Backscattered Ultraviolet Radiometer

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Calibration and Validation Legend

• PRT Platinum Resistance Thermometers
• NEDN/T Noise Equivalent Delta Radiance/Temperatur
  e
• ATOVS Advanced TIROS Operational Vertical
  Sounder (TOVS)
• TOAST Total Ozone Analysis using SBUV/2 and TOVS
• MSPPS Microwave Surface and Precipitation
  Product System
• NDVI Normalized Difference Vegetation Index
• SST Sea Surface Temperature
• UV Ultraviolet
• TPW Total Precipitable Water
• CLW Cloud Liquid Water

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ORA NOAA-18 Instrument Cal/Val Mission Goals

• Monitor and improve NOAA-18 instrument
  post-launch calibration
• Assess and quantify instrument noises though
  analyzing calibration target counts and channel
  measurements
• Monitor possible instrument anomaly and provide
  recommended solution
• Quantify satellite geolocation errors
• Characterize other biases in radiance and
  products such as cross-track asymmetry through
  forward modeling and inter-satellite calibration
• Validate NESDIS NOAA-18 products (ATOVS and
  MSPPS, TOAST, UV index, NDVI, SST) for
  operational implementation
• Provide early demonstration and assessments of
  NOAA-18 data for improving numerical weather
  prediction through JCSDA

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Our Team

• Mitch Goldberg ORA/SMCD Division Chief, -
  Management and Technical Oversight
• Fuzhong Weng ORA/SMCD/Sensor Physics Branch
  Chief and NOAA-18 cal/val team leader, instrument
  asymmetry and microwave products and algorithms,
  radiance bias assessments for NWP model
  applications
• Changyong Cao HIRS instrument calibration
• Fred Wu AVHRR VIS/IR instrument calibration
• Tsan Mo AMSU/MHS instrument calibration
• Jerry Sullivan AVHRR thermal channel
  calibration/ NDVI validation
• Tony Reale HIRS/AMSU/MHS sounding
  channel/products validation
• Mike Chalfant HIRS/AMSU/MHS sounding
  channel/products validation /geolocation
• Ralph Ferraro AMSU/MHS window channels/MSPPS
  products validation
• Larry Flynn SBUV product validation
• Tom Kleespies AMSU on-orbit verification
• Hank Drahos Sounding product validation
• Dan Tarpley AVHRR product NDVI monitoring
• John LeMashall Impacts assessments of NOAA-18
  data for NWP applications

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HIRS Cal/Val Summary

• HIRS intersatellite calibration using
  Simultaneous Nadir Overpassing (SNO)
• Use NOAA-17/18 HIRS data in both poles where SNOs
  occur
• Identified radiance biases between two HIRS
  instruments are affected by number of factors
  (e.g. instrument non-linearity, spectral
  response function, field of view..).
• More thorough analyses are planned to quantify
  these factors

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NOAA-18/17 HIRS Channel 6 Bias
Other HIRS channel biases are shown on the
webiste http//www.orbit.nesdis.noaa.gov/smcd/spb
/n18calval
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AMSU Cal/Val Summary

• AMSU antenna pattern correction (APC)
• Applied for Level-1b data
• APC coefficients at three beam positions (1, 15
  and 30) are tested for optimal removal of biases
• It is found that the APC scheme at beam 30
  substantially reduces the cross-track asymmetry
  in the AMSU-A1 module at 50.3 GHz

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Optimal Antenna Patten Correction Using the Coeff
at Beam Position 30
AMSU-A1-2 module (50 GHz) is best corrected with
the antenna pattern correction coefficients from
beam position 30. X-coordinate from -60 and 60
corresponds to beam position 1 to 30.
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Antenna Patten Correction Using the Coeff at Beam
Position 1
AMSU-A1-2 module (50 GHz) are corrected with
the antenna pattern correction coefficients from
beam position 1