1. Introduction to GSICS : Organisation, Membership and Scope
Mitch Goldberg, NOAA/NESDIS
GSICS Executive Panel chair
NOAA/NESDIS

2. ECMWF Meeting, Reading UK
June 22, 2001
GSICS Mission
To provide sustained calibration and validation of satellite observations
To intercalibrate critical components of the global observing system to climate quality benchmark observations and/or reference sites
To provide corrected observations and/or correction algorithms to the user community for current and historical data 2
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3. ECMWF Meeting, Reading UK
June 22, 2001
Or in technical terms:
Quantify the differences – magnitude and uncertainty
Correct the differences – physical basis and empirical removal
Diagnose the differences – root cause analysis
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4. GSICS Official Members
ECMWF Meeting, Reading UK
GSICS Official Members
June 22, 2001
NOAA
NIST
NASA
EUMETSAT
CNES
CMA
JMA
KMA
WMO
ISRO
IMD
JAXA
USGS
Roshydromet
ESA (observer)
CEOS Precipitation Constellation is working with GSICS via
GPM X-Cal Working Group.
GSICS current focus is on the intercalibration of operational satellites,
and makes use of key research instruments such as AIRS and MODIS
as reference instruments for the operational instruments 4
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5. Calibration is Critical for Climate Change Detection
Before intercalibraion
After intercalibration
Trend of global oceanic total precipitable water decreases from 0.54 mm/decade to 0.34 mm/decade after intercalibrations! Calibration uncertainties translate to uncertainties in climate change detection 5 5 5

6. Building Blocks for Satellite Intercalibration
Collocation
Determination and distribution of locations for simultaneous observations by different sensors (space-based and in-situ)
Collocation with benchmark measurements
Data collection
Archive, metadata - easily accessible
Coordinated operational data analyses
Processing centers for assembling collocated data
Expert teams
Assessments
communication including recommendations
Vicarious coefficient updates for “drifting” sensors

7. Other key building blocks for accurate measurements and intercalibration
Extensive pre-launch characterization of all instruments traceable to SI standards
Benchmark instruments in space with appropriate accuracy, spectral coverage and resolution to act as a standard for inter-calibration
Independent observations (calibration/validation sites – ground based, aircraft)

8. GSICS organization Overseen by GSICS Executive Panel
Assisted by Research Working Group and Data management Working Group
GSICS activities rely on:
GSICS Coordination Centre (GCC)
operated by NOAA/NESDIS
Processing & Research Centres (GPRC)
operated by each satellite operator
Calibration Support Segments (CSS)
including field sites and laboratories
GSICS as an element of the space-based component of the Global Observing System
GSICS activities rely on a GSICS Coordination Centre (GCC) operated by NOAA/NESDIS, several GSICS Processing and Research Centres (GPRC) operated by each satellite operator, and will benefit of Calibration Support Segments including field sites and laboratories.
Activities are overseen by a GSICS Executive Panel assisted by a Research Working Group and a Data management Working Group.
Coordination Center
Calibration Support Segments (reference sites, benchmark measurements, aircraft, model simulations)
Regional Processing Research Centers at Operational Space
Agencies

9. ECMWF Meeting, Reading UK
June 22, 2001
Current focus of GSICS
Interagency collaboration on algorithms (GRWG) and data exchange and formats(GDWG)
Product acceptance and documentation requirements, metadata standards, data formats, website standards
Routine intercalibration (monitor and correct) of all operational GEO Infrared imagers using IASI and AIRS and soon CrIS
MODIS and Deep Convective Clouds for visible channels
Intercalibration of LEO instruments
HIRS, SSMI, AMSU, MHS, AVHRR, AIRS, IASI, FY3,
GOME-2, OMI, SBUV
CrIS, ATMS, OMPS, VIIRS
Traceability
Campaigns
Key collocation datasets
Requirements for pre-launch calibration
Root causes and corrections 9 9
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10. CriS and IASI Band 2 Direct Intercomparisons
For band 2 at water vapor absorption region, CrIS and IASI are consistent to each other and the difference is close to a zero line. CriS and IASI are nearly benchmark quality measurements and are critical for vicarious calibration of other infrared sounder and imager measurements.

11. ECMWF Meeting, Reading UK
June 22, 2001
First international coordinated GSICS project is the intercalibration
of geostationary infrared channels with IASI and AIRS
Ch6
Ch4
Ch3
Ch2
IASI
AIRS
Web Accessible 11 11
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12. IMPACT on Cloud Coverage Classification MSG March 2009
Before GSICS correction
After GSICS correction

13. GOES Sounder Cloud-top pressure
Fairly noisy higher cloud pixels and missing clouds
Dynamic bias correction is the current NOAA NESDIS version.
GSICS seems to improve (less noise) upon the dynamic bias correction method for this case.

14. GOES Sounder Cloud-top pressure
More uniform cloud pixels and more low cloud

15. Impacts of GSICS Correction for SEVIRI on GFS Forecast
MSG SEVIRI CSR with and without GSICS bias correction
500 mb Anomaly Correlation fover NH

16. Engage the User Community
Satellite Community – generation of CDRs
New WMO Space Programme SCOPE-CM
ISCCP - Blended geo & leo cloud information
National programs - SDS, SAFs,
Satellite Community - NWP direct radiance assimilation
Reanalysis Community
Next ECMWF reanalysis –
GSICS first major deliverable: Correction Coefficients for all GEO IR using IASI/AIRS as reference from 2003 – 2010+
Satellite Acquisition Programs
Prelaunch instrument characterization guidelines
Cal/Val Plans
Request for new products:
GEO solar channels, LEO microwave instruments

17. Status of GEO-LEO Inter-Calibration
AIRS
IASI
Jan/07
Jan/08
Jan/09
Jan/10
current
GOES-11
GOES-12
GOES-13
Jun/07
Aug/08
Meteosat-9
Meteosat-7
MTSAT-1R
FY-2C
FY-2D
Near-real time monitoring and correction for six operational GEO with baseline algorithm
Geneva, 29 April 2010
GSICS Executive Panel Meeting

18. GSICS Product Portfolio
For Operational Meteorological Satellites
− Geostationary – IR & Solar
− LEO – IR, Solar, UV, and Microwave – Conical & Cross-track Scanners
− Current Operational & Historic Instruments
− In near real-time and re-analysis modes
GSICS Bias Monitoring
− Routine comparisons of satellite radiances against reference
GSICS Correction
− Function to correct issued radiances
− For consistent calibration with reference
GSICS Diagnosis
− Recommendations to modify practices
− Design and Operation of future satellite instruments

19. GSICS Procedure for Product Acceptance
Products progress from
Demonstration Mode
Through
Pre-Operational Mode To
Operational Mode
By a series of reviews
Over period of ~1.5yr
Subject to meeting
acceptance criteria

20. GSICS Product Acceptance Documentation
Product Algorithm Theoretical Basis Documentation (ATBD)
Discussion of physical principles supporting the product
Software Document
Algorithm flowchart
including data I/O, logic and software module descriptions
Software that meets GSICS standards
On coding, I/O, filename, and documentation (TBD)
Software verification results
Version Control Plan
- Describes process of performing software/model/measurement updates and archive

21. SCOPE-CM to maximize data usage Sustained and Coordinated Processing of Environmental Satellite Data
Users
Satellites & sensors
Satellite data
Essential Climate products
GOS
GSICS
Consistent Calibrated data sets
SCOPE-CM
Regional/Specialized Satellite Centres
Address the requirements of GCOS in a cost-effective, coordinated manner, capitalising upon the existing expertise and infrastructures.
Continuous and sustained provision of high-quality ECVs
GSICS enables the generation of Fundamental Climate Data records and provides the basis for sustained climate monitoring and the generation of ECV satellite products. 21

22. GPM affiliation with GSICS
ECMWF Meeting, Reading UK
June 22, 2001
GPM affiliation with GSICS
Research working group
- Consensus algorithms
Data working group
- Formats, Servers
GSICS Executive Panel
GRWG
GDWG
GCC
CSS
GPRC
Calibration Support
Segments
Coordination Center
Regional Processing Research
Centers at Satellite Agencies
GPM X-Cal
Working Group
CSS
GPRC
CSS
GPRC
GPM X-cal:
Plan to sustain X-cal in future
Similar Structure to GSICS
Interested in using GSICS product acceptance procedure
Precipitation Processing
System at Goddard
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23. GSICS Outcome
Coordinated international intersatellite calibration program
Exchange of critical datasets for cal/val
Best practices/requirements for monitoring observing system performance
Best practices/requirements for prelaunch characterisation (with CEOS WGCV)
Establish requirements for cal/val (with CEOS WGCV)
Advocate for benchmark systems
Quarterly reports of observing system performance and recommended solutions
Improved sensor characterisation
High quality radiances for NWP & Climate

24. GRUAN Representation at GRUAN Expansion Workshop
Contributed to White Paper on Satellite Cal/Val
Emphasis on Quality, not quantity of radiosondes
Launches timed for satellite overpasses
Can select sites where these are synoptic hours (0z, 12z)
Real-time evaluation of representativeness errors
Based on observed variability in space & time
3-way interaction for validation of L2 products
e.g. UTH (GSICS-GRUAN-SCOPE-CM/CMSAF)

25. Summary GSICS is Global Space-based Inter-Calibration System!
Focuses on Level 1 data => FCDR
GSICS does not (generally) re-calibrate archives of data
But provides products to correct calibration of real-time and archive data to be consistent with reference instruments
Also provides tools to monitor biases in near real-time
To date, GSICS have concentrated on current GEO imagers
Developed Procedure for Product Acceptance
Thorough documentation with traceability
May be applied to 3rd party products
Need to ensure consistency between products
For different instruments – contemporary and historic

26. User Messaging Service
Official channel of communication from GSICS to its users
Register at
All registrants receive the GSICS newsletter
Optional: news about current and future GSICS products, and significant instrument events