Calibration and Validation Activities at NOAANESDIS

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Calibration and Validation Activities at
NOAA/NESDIS

• Changyong Cao
• On behalf of James Yoe
• NOAA/NESDIS/Office of Research and Applications
• CEOS WG on Cal/Val
• June 15-17, 2004, Sioux Falls, SD

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Overview Scope and GoalsExamples of Methods
and Results

• Current operational NOAA instruments AVHRR,
  HIRS, AMSU, SBUV, GOES Imagers/Sounders
• Assure Functionality of Current/Near-Future
  Operational Systems
• Develop maintain on-orbit calibration approach,
  algorithms, databases
• Oversee pre-launch sensor calibration
• Perform post-launch checkout, monitoring, and
  trouble-shooting
• Apply Experience to Design of Future systems
• Define future measurement requirements support
  development of future systems (NPP, NPOESS,
  GOES-R, active sensors)
• Assure Required Accuracy, Stability,
  Inter-comparability
• Serve Community of Data Providers and Users
• NOAA, Other US Government Agencies, Academia and
  Industry, International partners

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Intersatellite Calibration with Simultaneous
Nadir Overpass (SNO) Observations

• Two satellites pass the same place at their
  nadirs within a few seconds (routinely predicted
  with SGP4)
• Occurs for all satellites with different
  altitudes (typically once every few days) In the
  polar regions for sun synchronous satellites
• SNO time series very useful for intersatellite
  calibration of IR/VIS/NIR, and Microwave sensors
• Website www.orbit.nesdis.noaa.gov/smcd/spb/calibr
  ation/intercal/
• Several publications

Cao et al, J. Atmospheric Oceanic Tech, 2004
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Applications of the SNO method

• Used for postlaunch checkout, longterm monitoring
  of instrument performance, and re-analysis of
  historical data for time-series analysis to
  achieve intersatellite calibration consistency
• Procedure is implemented for NOAAs AVHRR, HIRS,
  and AMSU instruments also used for Terra/Aqua
  MODIS/AVHRR by NASA/MCST
• Complement to GOES/POES intercal
• Future work for inflight spectral cal with
  hyperspectral thermal sensors
• Examples (to the right)
• SNO method reveals seasonal biases caused by
  spectral response differences for HIRS (upper
  right)
• SNO method shows excellent agreement between
  satellites for AMSU (low right)

HIRS stratosphere channel (longwave infrared 690
cm-1)
AMSU mid-troposphere channel
(Microwave)
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AVHRR Reprocessing Project

• Re-processing of AVHRR data for better product
  quality for climate studies
• Standardize calibration coefficients and radiance
  calculation procedure, such as non-linearity
  correction, and band correction coefficients
• Use the SNO method to establish the calibration
  link among satellites
• Provide consistent calibration coefficients with
  improved calibration accuracy

AVHRR
?T in
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AVHRR VIS/NIR Vicarious Calibrationusing the
Libyan Desert Target

• NOAA 16 AVHRR Albedo

• NOAA 17 AVHRR Albedo

CH1
CH2
CH3
Courtesy X. Wu
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NIST verification of HIRS filter spectral
response functions (HIRS Ch 1, CO2 Q-branch,
25mb, worst case)
NIST at 30, 25, 20, and 15 C
Vendor
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GOES Star Based Calibration
Courtesy X. Wu, 2004
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(Passive) Microwave Sensors

• Past
• Microwave Sounding Unit (MSU)- NOAA-6 to 14
• Present
• Advanced Microwave Sounding Unit-A (AMSU-A)
• Advanced Microwave Sounding Unit-B (AMSU-B)
• Future
• Humidity Microwave Sounder (MHS) NOAA-N
• Advanced Technology Microwave Sounder (ATMS)
  NPP/NPOES
• All sensors are well calibrated before launch and
  on-orbit data are monitored for calibration
  accuracy
• Data are used for temperature humidity sounding
  and studies of climate trend
• AMSU data have significant positive impact on
  global weather forecast scores

Courtesy T. Mo
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Status of NESDIS Uniform Instrument Monitoring
System

• User-friendly (web-based) system with high level
  info, documentation, meta-data, eng radiometric
  data archived undertaken at NRC recommendation
• System requirements document completed December
  2003
• System specification document in final stage of
  preparation
• Government team will meet week of 14 June 2004 to
  decide which architecture to employ
• Funding in place to develop prototype system in
  FY04-05.

Courtesy T. Kleespies
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Ocean Color - MOBY Vicarious Calibration

• Vicarious Calibration Required for Ocean Color
  Science
• Pre-flight Laboratory and On-board Sensor
  Calibrations (TOA 4-5) Cannot Meet the Accuracy
  Requirements for Ocean Color Science
  Applications.
• A Minimum of an Order of Magnitude Improvement in
  Calibration Accuracy is Required.
• MOBY Presently Provides Water-Leaving Radiances
  at the 5 (surface) uncertainty Level Which Meets
  the Minimum Accuracy Requirement. MOBY has
  demonstrated excellent long-term Stability over
  the past 6.5 yrs.
• MOBY has provided a NIST Traceable Scale for all
  of the Major Ocean Color Missions Since the mid
  1990s. A necessary requirement for producing
  Climate Quality Data Records.

Courtesy D. Clark
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MOBY Instrument and Spectral Time Series of MODIS
ocean color bands (Accuracy 4 -5)
Courtesy D. Clark
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SST Product Validation

• Periodic global GAC AVHRR SST validation has been
  conducted continuously since 1983
• SST retrieval precision has gradually improved to
  within 0.5 K rms of buoy matchups
• GOES SST became operational since Dec. 2000

Courtesy ORA/ORAD/SST Team
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GPS IPW (Integrated Precipitable Water) stations
operated by the NOAA Forecast Systems Lab.
Courtesy NOAA/FSL (S. Gutman)
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GPS measured vs. AIRS derived IPW for the CONUS
(All match-ups within 0.25 deg lat/lon and
within 30min)
(b)
(a)
(c)
(d)
Figure 3.
Red line linear fit for the match-up data.
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COLLOCATED RADIOSONDES
AIRS
NOAA-16
Courtesy Mitch Goldberg
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MODIS and AVHRR NDVIs Compared for a Site in
South Dakota (16 day composites in 2001)
NDVI Calibration/Validation
Effect of AVHRR Spectral Response on longterm
NDVI time series studies
Courtesy X. Wu
Courtesy ORA/SMCD/EMB, K. Gallo
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GOES land surface temperature and US Climate
Reference Network (USCRN) surface temperature
comparison. 1 3 April 2004 EROS Data Center
For further information contact Kevin Gallo
(NOAA/NESDIS, kevin.p.gallo_at_noaa.gov)
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SBUV/2 Ozone Cal/Val Level 2 Ground-based
Comparisons
In press, Miller et al., JGR Atmospheres
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NPP/NPOESS Cal/Val Activities

• VIIRS, CrIS, ATMS, and OMPS will replace AVHRR,
  HIRS, AMSU, and SBUV
• NPP NPOESS Preparatory Project (IPO/NASA)
• NPOESS Data Exploitation Team (NOAA)
• Oversight of and support to NPOESS cal/val
• Independent verification and monitoring
• Liaison between IPO and NOAA central/civilian
  users on cal/val issues
• Cal/val support to NOAA unique products
• Ensure continuity from POES to NPOESS
• NPOESS Prelaunch/postlaunch cal/val meetings
• Currently focus on prelaunch tests, instrument
  performance issues and potential science impacts

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Summary

• NOAA/NESDIS has extensive calibration/validation
  experience in both prelaunch and postlaunch in
  atmosphere, sea surface temperature, ocean color,
  ozone, and land validation using a variety of
  sources, including other satellites, in-situ, and
  ground-based remote sensors
• SNO method very useful for the cal/val of all
  radiometers
• Continued support to NOAA operational
  instruments, and reprocessing for climate studies
• Transition to MetOP and NPOESS

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• Backup slides

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GOES GSIP-fd surface temperature and CRN surface
temperature comparison. 1 3 April 2004 EROS
Data Center
For further information contact Kevin Gallo
(NOAA/NESDIS, kevin.p.gallo_at_noaa.gov)
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Future Plans

• Communicate more comprehensively between WGCV and
  NOAA/NESDIS/ORA
• SAR and Scatterometry
• Atmospheric Chemistry
• Aerosols
• Air quality
• Explore METOP/NPOESS c/v consistency

Office of Research and Applications, soon to
become the Center for SaTellite Applications and
Research, (STAR)
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Near Future Validation of AQUA/AIRSTemp.
Differences (AIRS - RS80 Radiosonde)

• Jiang and McMillin

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Near Future Operational AQUA/AIRS IPWV Validation
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Future Operational GPS/RO Vertical Coverage
Verification
CHAMP Data courtesy NASA/JPL Alternate Sources
UCAR/CDAAC and GFZ Potsdam Statistics prepared
by Rama Varma Raja, IMSG for NOAA
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Future Sensors Preliminary CHAMP Moisture Check

• Prepared by Rama Varma Raja

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Future Satellite Sensors -Doppler Wind Lidar

• Highest Unmet Data Requirement for NWP
• Technologically Challenging
• Demonstration Space Instrument (ESAs ADM)
  expected in 2007
• Ground-based Instruments for technology
  development, assessment (left)

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Histograms of the differences between
corresponding pairs of (left) 1-minute
line-of-sight projected horizontal (LOSH) Doppler
velocities for the GroundWinds and mini-MOPA
DWLs, and (b) GroundWinds (10-min averaged) LOSH
and the component of the height-averaged
radiosonde horizontal wind along the DWL azimuth
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An Eye to the Future

• Communicate more comprehensively between WGCV and
  NOAA/NESDIS/ORA
• SAR and Scatterometry
• OC
• Microwave sounders
• Atmospheric Chemistry
• Aerosols
• Land and Surface Products
• Explore METOP/NPOESS c/v consistency