Changyong Cao & Fuzhong Weng NOAA/NESDIS/STAR STAR Calibration Team September 20, 2006

1. Integrated Satellite Instrument Calibration/Validation SystemPreliminary Design Review (PDR)Introduction Changyong Cao & Fuzhong Weng NOAA/NESDIS/STAR STAR Calibration Team September 20, 2006

2. Integrated Instrument Calibration/Validation System Preliminary Design Review (PDR)Agenda (2:00 pm - 4:30pm, Sept. 20, 2006) • Opening remarks Weng 5 min • Introduction Cao 15 min • System Architecture Overview Iacovazzi 15 min • Inter-satellite and Inter-sensor Calibration Iacovazzi &Wang 30 min • Instrument Performance Monitoring & Cal/Val at Reference Sites Wang 15 min 10 minute break • GOES calibration and intercalibration Wu 20 min • Calibration for DMSP Satellites Weng 20 min • Recalibration for Climate Applications Ciren 15 min • Summary Cao 5 min

3. Team Members • Mitch Goldberg (STAR) Program management & initiatives • Fuzhong Weng (STAR) Program management & DMSP subsystem • Changyong Cao (STAR) Project lead, algorithm, system design, and instrument performance analysis • Fred Wu (STAR) GOES subsystem and POES/GOES vicarious calibration • Tsan Mo (STAR) Microwave calibration • Jerry Sullivan (STAR) Infrared imager calibration • Bob Iacovazzi (ERT) System Architecture, integration, and microwave intercalibration • Likun Wang (QSS) Instrument performance monitoring, IR sounder intercalibration, reference sites, and RTM • Pubu Ciren (QSS) Recalibration for climate • Banghua Yan (QSS) DMSP Calibration • Yaping Li (IMSG) Website development This project is partially funded by IPO/IGS, STAR, ESDIM, and OSD/PSDI

4. ORA Satellite Cal/Val Program Road Map (2005 - 2012) By 2012, Global Environmental Observation System of Systems (GEOSS) data will be calibrated with a high quality for uses in the environmental data stewardship Integrated cal/val enterprise system that delivers to WMO and other users SNO data. Resources: Develop NPP, NPOESS and GOES-R calibration algorithms which are part of Cal/Val OK Deficiency New cal/val sites deployed for GEOSS and GHG products Develop FY-3 series, METOP-A IASI and GOME2 calibration algorithms which are part of cal/val system More product validation using existing validation sites will lead to robust products in NOAA operational products such as temp/water profiles in storm conditions Integrate validation efforts to form prototype cal/val system Science Advance DMSP microwave sounding instrument bias and anomaly correction algorithms are incorporated. GOES and EOS Integrate DMSP, GOES and EOS into sensor performance monitoring NOAA POES instrument on-board performance can be monitored with inter-sensor and intra-sensor calibration, radiative transfer simulations. The anomaly can be captured in near-real time and the instrument biases can be corrected An inter-sensor calibration system for monitoring sensor performance Individual POES/GOES sensor calibration Establish a basic infrastructure for operational POES instrument calibrations through on-board calibrators and vicarious technique for quantifying instrument noise and linear and non-linear calibration. 2005 2006 2010 2011 2012 2007 2008 2009

5. Why Integrated Cal/Val System?- Requirements and expectations Weather prediction • Advanced models demand more accurate observations • Forecast accuracy has increased dramatically - further improvements can be realized from more accurate measurements Climate: Is the climate changing? • Satellites provide the global observations needed to monitor global climate change • But climate change is slow (for example, temperature trends of only about 0.2 C/decade) • Excellent instrument calibration is vital for detecting these trends and providing the nation with the information needed to make informed decisions Requirements for reliable quantitative information from environmental satellites are more demanding

6. Historical Perspective on Cal/Val Paradigm shift in Meeting the Changing Cal/Val Requirements GEOSS GSICS/CEOS MW/IR/VIS/UV/LM/RO POES/NPOESS/GOES-R Climate instrument calibration requirements Bias adjustments in radiance assimilation for NWP Intersatellite calibration Spatial, spectral, inter-sensor calibration, and RTM Prelaunch, onboard, vicarious, GOES/POES calibration Piecemeal approach (fragmented, case by case study) Integrated system (One AVHRR orbit needs 50 floppies)IT evolution (One USB holds 14 orbits of AVHRR data) 2000 &before 2002 2004 2006 Related Projects: PSDI, G-PSDI ESDIM, ORA-base, JSDI, IGS, GOES-R, SDS

7. The Engineering and Science Aspects of Cal/Val partners&users OSO/OSDPD Engineering Issues 24/7 Data Acquisition & Processing Spacecraft & instrument Telemetry Trending & Status Monitoring STAR JCSDA Science Issues Increasing awareness of calibration impacts on products (assimilation, aerosols, ndvi, temperatures) Issues in radiometric, spectral, spatial accuracy, bias, noise, & trends Reference sites RTM NWP WMO NCDC SDS Academia • System & Instrument vendors • (Prelaunch, early checkout & anomaly resolution) • OSD & NASA International Requirements to Specifications

8. Cal/Val is Evolving • An integrated cal/val is needed to achieve a high level of radiance accuracy for numerical weather and climate applications • Any single component alone (instrument performance trending, or radiative transfer models…) can not meet the needs. • Calibration is no longer just calculating the slopes and intercepts for converting counts to engineering units. It is an end-to-end process from RDR (Raw data record) to SDR (Sensor Data Record), EDR (Environmental Data Record), and CDR(Climate Data Record). Calibration is the foundation for all quantitative satellite products. • Radiance validation is an integral part of calibration. While user feedback is helpful, we shouldn’t rely on users to tell us what’s wrong in our calibration! In some cases, calibration may rely on validation (e.g., sounder scan bias, MOBY for ocean color, etc.) • Improving calibration requires innovative R&D. New methodologies need to be developed to meet new challenges, which may also bring in fundamental changes (e.g., SNO/SCO, and moon calibration)

9. Objectives • Develop an integrated solution to meet the cal/val needs of weather, water, and climate applications • Transition from a fragmented system and piecemeal approach to an integrated system, because the integrated system will be more powerful as a whole than as a sum of its pieces • Strengthen NESDIS core competency in cal/val to meet new challenges and initiatives

10. Integrated Cal/Val System Framework Cal/Val subsystems Collaboration with Partners Academia JCSDA CoRP WMO OSDPD OSO OSD NCDC Data processing Spacecraft & instrument status SNO archive & distribution Instrument specs. Meta data &archive RTM & cal/val Product validation Validation & feedback

11. Major Components • Independently verify radiances by inter-satellite calibration using the SNO/SCO method • Monitor instrument performance with an on-line instrument performance trending system • Develop inter-sensor calibration capabilities, which includes the intercomparison between imager and sounder channels, and inter-channel calibration to monitor the radiometric and spectral calibration stability in the longterm. • Integrate our vicarious calibration capabilities, including using the desert sites for visible/near-infrared channels, and using the mid and upper atmosphere to check for scan asymmetry of sounding channels. • Integrate state-of-the-science radiative transfer models, which will allow us to resolve spectral induced biases, and perform regular validations at selected sites, such as the ARM sites. • Establish calibration consistency and traceability among NPOESS, POES, and GOES.

12. Web Interface to the Integrated Cal/Val System

13. Simultaneous Nadir Overpass (SNO) Method-a core component in the Integrated Cal/Val System POES intercalibration • Useful for remote sensing scientists, climatologists, as well as calibration and instrument scientists • Support new initiatives (GEOSS and GSICS) • Significant progress are expected in GOES/POES intercal in the near future • Unique capabilities developed at NESDIS • Has been applied to microwave, vis/nir, and infrared radiometers for on-orbit performance trending and climate calibration support • Capabilities of 0.1 K for sounders and 1% for vis/nir have been demonstrated in pilot studies • Method has been adopted by other agencies GOES vs. POES

14. Demonstrated SNO Capabilities AVHRR/MODIS VIS/NIR channel (0.65um) AVHRR/N18 MODIS/Aqua Sample area Reflectance Min Max Mean Stdev Band 1 AVHRR 0.4301 0.4728 0.4523 0.008894 Band 1 MODIS 0.4800 0.5401 0.5113 0.012135 For this area with 205 samples, the difference between MODIS and AVHRR is about 13%, at 99% confidence level with uncertainty+/-0.4%. Spectral differences is not the main contributor to the this discrepancy, according to radiative transfer calculations. Good example of calibration traceability issue. SNO VIS/NIR example Lat=79.82, SZA=82.339996, cos(sza)=0.13, TimeDiff 26 sec, Uncertainty due to SZA diff 0.1%,

15. Integrated Approach to Instrument Performance Analysis An integrated view of the NOAA18 noise problem: from onboard calibration (NEDN), to earth view digital count, earth view radiance, SNO bias, and products. SNO bias NOAA17 vs NOAA18 HIRS Ch2 Instrument noise (NEDN)

16. Benefits of the integrated instrument cal/val system • Significantly strengthen NESDIS core competency in operational satellite instrument calibration/validation • Indispensable tool for instrument performance diagnosis. • Automation allows us to support the calibration of a large number of satellite instruments • End–to-end calibration allows us to further improve data accuracy and quality to ensure longterm user confidence for weather and climate applications • Ability to support many programs and initiatives

17. Programs/Initiatives supported • For GSICS, intersatellite calibration is critical • Extensive study is underway for establishing the links between POES and NPOESS instruments, using EOS proxy data. • Climatologist are very interested in the SNO/SCO method. • Initiatives to establish calibration links with foreign satellites under GEOSS. • Effort in establishing absolute calibration with the NOAA/NIST initiative

18. Part 2: System Architecture Overview (see ICVS_PDR_Part2_Architecture_Bob.ppt file)

19. Summary • The Integrated Cal/Val system is based on many years of R&D by STAR scientists and supported by several programs. • The system plays a vital role in strengthening the core competency of our operational environmental satellite program. • Automation allows us to develop an efficient and productive system to support many programs and initiatives. • Preliminary design of the system is now available, prototyping of the major components have been done. • Areas of further R&D are also identified.

20. Selected recent publications Weng, F., M. Goldberg, and C. Cao, 2006, NOAA Integrated Satellite Calibration and Validation System in Support of Global Earth Observation System of Systems (GEOSS), A Report to the 36th COSPAR Cao, C., F. Weng, M. Goldberg, X. Wu, and J. Sullivan, 2006, Toward An Integrated System For The Calibration/Validation Of Multisensor Radiances From Operational Satellites, Proceedings of the Satellite Meteorology and Oceanography, Atlanta, GA. Cao, C., 2006, Establishing on-orbit calibration links among operational satellite radiometers for the implementation of GEOSS, Proceedings of SPIE, Vol. 6301, San Diego, CA. Iacovazzi, R., and C. Cao, 2006, Quantifying EOS-Aqua and NOAA POES AMSU-A Brightness Temperature Biases for Weather and Climate Applications Utilizing the SNO Method, Submitted to the Journal of Atmospheric and Oceanic Technology Wang, L, C. Cao, and P. Ciren, 2006, Assessing NOAA-16 HIRS Radiance Accuracy Using Simultaneous Nadir Overpass Observations from AIRS, submitted to JTECH. Zou, C., M. Goldberg, Z. Cheng, N. Grody, J. Sullivan, C. Cao, and D. Tarpley, 2004, MSU channel 2 brightness temperature trend when calibrated using the simultaneous nadir overpass method, in press. Cao, C., P. Ciren, M. Goldberg, F. Weng, and C. Zou, 2005, Simultaneous Nadir Overpasses for NOAA-6 to NOAA-17 satellites from 1980 to 2003 for the intersatellite calibration of radiometers, NOAA Technical Report Cao, C., H. Xu, J. Sullivan, L. McMillin, P. Ciren, and Y. Hou, 2005, Intersatellite radiance biases for the High Resolution Infrared Radiation Sounders (HIRS) onboard NOAA-15, -16, and -17 from simultaneous nadir observations. Journal of Atmospheric and Oceanic Technology, Vol.22, No. 4, pp. 381-395. Cao, C., M. Weinreb, and H. Xu, 2004, Predicting simultaneous nadir overpasses among polar-orbiting meteorological satellites for the intersatellite calibration of radiometers.  Journal of Atmospheric and Oceanic Technology, Vol. 21, April 2004, pp. 537-542. Cao, C, and P. Ciren, 2004, Inflight spectral calibration of HIRS using AIRS observations, 13th conference on Satellite Meteorology and Oceanography, Sept. 20-23, 2004, Norfolk, VA. Ciren, P. and C. Cao, 2003, First comparison of radiances measured by AIRS/AQUA and HIRS/NOAA-16&-17, Proceedings of the International ATOVS Working Group Conference, ITSC XIII, Sainte Adele, Canada, Oct. 29, - Nov. 4, 2003. Cao, C., and A. Heidinger, 2002, Inter-Comparison of the Longwave Infrared Channels of MODIS and AVHRR/NOAA-16 using Simultaneous Nadir Observations at Orbit Intersections, Earth Observing Systems, VII, Edited by W. Barnes, Proceedings of SPIE Vol. 4814, pp. 306-316. Seattle, WA.  Heidinger, A, C. Cao, and J. Sullivan, 2002, Using MODIS to calibrate AVHRR reflectance channels, Journal of Geophysical Research, Vol. 107, No. D23, 4702. Wu, A., X. Xiong, C. Cao, X. Wu, W. Barnes, 2004, Inter-comparison of radiometric calibration of Terra and Aqua MODIS 11um and 12 um bands, Proceedings of SPIE, 2004, Denver, CO.