Working Group on Calibration and Validation

1. Metrological Assurance of GEOSS Radiometric Data Compatibility. An Example of Assuring High Quality Basic Climate Data Records(ADC Tasks DA-06-02 and CL-06-02) Working Group on Calibration and Validation (CEOS WGCV 27, London, United Kingdom, 12-15 June 2007)

2. WGCV26 Russia - USA paper:Uniformity of Radiometric Measurements as an Important Element of Data Quality Assurance within the GEOSS ProgramV. Krutikov- Federal Agency on Technical Regulating and Metrology, Russia; V. Sapritsky, A. Bourdakin, V. Ivanov, B. Khlevnoy, S. Morozova, S. Ogarev, A. Panfilov– VNIIOFI, Russia; R. Datla, G. Fraser - NIST, USA;G. Bingham, T. Humpherys, J. Tansock, A. Thurgood- Space Dynamics Laboratory (SDL), USA;V. Privalsky – Vega International, Inc., USATerms and definitionsEnsuring traceable and stable instrument radiometric scales

3. Terms and definitions

4. Ensuring traceable and stable instrument radiometric scales IThe goal is to meet the most stringent requirements for radiometric instruments that are used for precision monitoring of global climate change Satellite Instrument Calibration for Measuring Global Climate Change. NISTIR 7047. Our suggestion is to use calibration devices based upon the phenomenon of phase transition of eutectic alloys or pure metalsin both the ground calibration and the in-flight monitoring systems

5. Solution for the 0.3 m – 3 m region Integrating sphere Instrument Fixed-point blackbody Solution for the 3 m – 25 m region Variable-temperature blackbodies Instrument Fixed-point blackbody

6. In-flight monitoring I • Spectral region 0.3 – 3.0 μm • Stability - 0.1 %/d • Using the moon as a test source • Spectral region 3 - 25 μm • Stability - 0.01 K/d Approaches to problem solution • Develop and use onboard sources based upon phase transition of substances. Studies are required to • select suitable substances (2006), • determine their properties under the ground environment (2006), • determine their properties under the space environment, • design onboard sources. • Develop a space-borne radiometric calibration facility

7. Ensuring traceable and stable instrument radiometric scales IIInvestigations in the area of metrological assurance of future GEOSS radiometric data compatibility are continuing in 2007

8. Ground calibration systems IDeveloping a Russian set of standards for calibration of instruments operating within the spectral region from 0.3 m to 25 m Requirements

9. Ground calibration systems II Calibration system for instruments operating within the region from 0.3mto 3 m

10. Ground calibration systems III Calibration system for instruments operating within the region from 3mto 25 m

11. In-flight monitoring IIIn 2006, some promising laboratory studies targeted at the development of high-stability onboard benchmark sources on the basis of phase-transition materials were carried out at VNIIOFI in 2006 This allowed us to start preparations for further experiments with phase-transition materials under microgravity conditions on board of the International Space Station

12. In-flight monitoring III Preparing for a space experiment «Studying the effects of micro-gravity upon the melting/freezing phase transitions of eutectic alloys» VNIIOFI – Rostekhregulirovanie, TSNIIMASH, RKK «ENERGIYA» - Roskosmos

13. Participants of Task DA-06-02 contributing to radiometric data compatibility goal

14. Joint Efforts According to the Implementation Plan for GSICS, the GSICS Calibration Support Segments activities include: • Earth-based reference sites, • Extra-terrestrial calibration sources, • Model simulations, • Benchmark measurements of the highest accuracy by special satellite and ground-basedinstruments will help to conduct satellite instrument calibrations with sufficient accuracy

15. Further suggestions on solution of Climate Task CL-06-02 - I Ensuring the long-term (for decades) high stability of GEOSS’s instruments is of critical importance for registration of low-intensity changes of climate. Therefore, the proposed new idea to monitor the stability of onboard instruments with the help of standard sources on the basis of phase-transition materials looks very promising for solving Climate Task CL-06-02.

16. Further suggestions on solution of Climate Task CL-06-02 - II A paper prepared for publication: On Metrological Support for Climatic Time Series of Satellite Radiometric Data V. Sapritsky, A. Burdakin, B. Khlevnoy, S. Morozova, S. Ogarev, A. Panfilov – All-Russian Institute for Opto-Physical Measurements(VNIIOFI), Russia; V. Krutikov - Federal Agency on Technical Regulating and Metrology, Russia; G. Bingham, T. Humpherys, J. Tansock, A. Thurgood - Space Dynamics Laboratory (SDL), USA; V. Privalsky - Vega International, Inc., USA.

17. Further suggestions on solution of Climate Task CL-06-02 - III According to • Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC. 2004. GCOS – 92 (WMO/TD #1219) and • Systematic Observation Requirements for Satellite-based Products for Climate. 2006. GCOS – 107 (WMO/TD № 1338), a necessary condition for obtaining fundamental climate data records is the use of high-quality observation instruments whose stability and accuracy are sufficient for climate monitoring purposes. The use of the phenomenon of phase transition of pure metals and eutectic alloys seems to be a promising means to achieve a satisfactory solution of the instrument calibration task for climate monitoring purposes.

18. Further suggestions on solution of Climate Task CL-06-02 - IV

19. Thank you