Participating SDR Team Members Cross-track Infrared Sounder Calibration and Validation Plan of the JPSS Crosstrack Infrared Sounder (CrIS) Deron Scott1, Gail Bingham1, Chad Fish1, Harri Latvakowski1 , Mark Greenman1, Mark Esplin1, Vladimir Zavyalov1, Yong Han2 1Space Dynamics Laboratory, Utah State University 2National Oceanic and Atmospheric Administration Abstract Calibration and Validation Process Calibration and validation of sensors is important for understanding how a sensor operates during its mission and shows the level of measurements that can be expected. Calibration is an on-going process throughout the mission but is most critical when the complete system comes together and during its initial stage after reaching orbit. Careful planning is required to accurately and efficiently collect data that characterizes the sensors response, process the data in a timely manner to generate results that are useful to mission science, apply the results for processing algorithms, and have a process for improvement as additional information about the sensor becomes available. This paper describes the calibration and validation plan of early on-orbit operations of the Cross-track Infrared Sounder (CrIS). It focuses on the science data record (SDR) portion of the CrIS mission. The CrIS sensor is currently integrated on the NPP spacecraft that is scheduled to launch in October 2011. Early Orbit Check-out Purpose: To allow post-launch Cal/Val activities to begin, the NPP spacecraft must be successfully launched and checked out and sensor activation initiated. Because CrIS has cryogenic temperature components, it will undergo an extensive outgas period before it is for ready for performance assessment. The outgassing period will reduce/avoid the likelihood of cryo-ice or other contaminants to build up on the sensor Activation activities have the primary objective of safely and effectively getting CrIS into operational conditions, including electrical checkout, out-gassing, cooling the detectors, setting the gains and bit trim masks and other necessary functions to allow data flow to begin. CrIS sensor will be activated through a stepwise process that moves the instrument from the OFF mode to the DIAGNOSTIC mode. NGST assisted by ITT and working with NASA spacecraft have responsibility to perform the sensor activation. MIT will review and contribute as needed. Pre-launch Ground Testing Calibration/Validation Completed Rehearsal Using Proxy Data Sets On-going Launch and Sensor Activation Early Orbit Check-out L + 55 days Intensive Cal/Val L + 90 days Long-term Monitoring L + 300 days NPP Mission Phase Participating SDR Team Members NASA, NOAA-STAR JPSS Program ITT UWisc./SSEC UMBC Raytheon NGAS USU/SDL MIT/LL Aerospace Cross-track Infrared Sounder (CrIS) ITT Corporation The Cross-track Infrared Sounder (CrIS) is part of the NPP system that will be used to produce accurate temperature, water vapor, and pressure profiles on the Joint Polar Satellite System (JPSS) operational missions. Aspects of CrIS related to calibration: CrIS sensor measures top of the atmosphere spectral radiance, which is then further processed to develop the temperature, pressure, and water vapor profiles. Fields of Regard 3 x 3 grid 14 km nadir FOV spatial resolution On-board internal calibration target 2200 km swath width ±50° Cross track Scans RDR = Raw Data Record SDR = Sensor Data Record EDR = Environmental Data Record CrIS Swath 2200km RDRs EDR Algorithms Decode Spacecraft Data SDR Algorithms • CrIS 3x3 Array of CrIS FOVs (Each at 14-km Diameter) Central or Regional Ground Stations SDRs 0.1 1 10 100 1000 200 210 220 230 240 250 260 270 280 290 Temperature (K) Pressure (mb) EDRs Co-located ATMS SDRs CrIS CrIS Sensor Overview: Intensive Calibration and Validation Purpose: To derive calibration parameters and validate operation of the CrIS sensor. Tasks from early orbit check-out, ICV, and Long-term monitoring flow into each other making dividing lines blurry. During ICV, any anomalies or inconsistent data sets will be investigated to determine if adjustments in the sensor need to be made. The following tasks will be completed (Note, tasks are numbered consistent with the calibration plan.) : Task 1: Interferometer Optimization Task 2: Set Neon Lamp Calibration Task 3: IR Channel Programmable Amplifier Gain Check and Adjustment Task 4: Bit Trim and Impulse Mask Checks Task 7: Detector Linearity Check and Adjustment Task 8: Geolocation Calibration Task 9: ICT External Environmental Radiance Model Assessment and Tuning Task 10: Verification of Onboard Filtering and Decimation of the Interferogram Task 12: Spike Analysis Task14: Correlated/Uncorrelated Noise Characterization Task 15: Residual Analysis Task 18: Error Budget Assessment Task 20: Early Broadband Radiance Comparisons with GOES and other Geos Pre-launch Ground Testing Calibration/Validation Purpose: Characterize sensor, determine calibration coefficients and Look up tables (LUTs), verify data processing algorithms Four TVAC tests performed Thermal-Vac Testing performed at ITT and Ball Aerospace Initial system level checkout Calibration parameter derivation Final Validation Spacecraft system level TVAC test Parameters Derived Long-Term Monitoring Purpose: To verify that the sensor continues to operates at well characterized levels and variations are documented and understood. Cal/Val team provides careful tracking and comparisons with reference systems working closely with EDR and Centrals teams. This phase will include SI traceability establishment via aircraft campaign. Continued evaluation of instrument and SDR code issues and IDPS SDR code fine tuning. The following tasks were started during ICV and will be completed: Task 5: Noise Equivalent Radiance Difference (NEdN) Check Task 6: Spectral Calibration Task 11: Responsivity and Sensitivity Characterization Task 13: Ice Contamination Analysis Task 16: Double-difference Cross Comparison with AIRS and IASI Task 17: SNO Cross Calibration with AIRS and IASI Task 19: CrIS RDR and SDR Trending and Monitoring CrIS follows two great, well calibrated instruments to orbit SDR Cal/Val has/will utilize similar procedures Co-existence enables direct comparison, and good comparisons from GSICS Cal/Val team brings direct AIRS/IASI experience CrIS AIRS IASI Ground testing results show that CrIS is an outstanding instrument compliant to requirements with few exceptions Rehearsal Using Proxy Data Sets Purpose: Verify that software tools can read and process data from sensor. Validation is based on comparisons of CrIS radiances with other satellite sensors Data sets available: P-72: 6 orbits of contiguous data using AIRSS as a baseline NCT?-V? Continuous data sets from multiple rehearsals multiple versions using thermal-vacuum data as a base line IASI proxy: Single orbit using IASI as a baseline Data from TVAC testing Analysis tools available: GRAVITE: Software and hardware system to allow easy access and processing of data sets. TVAC tools: Many of the analysis tools developed during TVAC testing will be used during on-orbit analysis. GTP: Gravite transfer protocol. Used to retrieve directories and files. Peate: Product and evaluation test element. Includes both atmospheric and sounding elements CLASS: Comprehensive Large Array-data Stewardship System. Long-term data repository Summary: NPP Mission CrIS integrated into spacecraft awaiting October launch Ground testing performed in 4 thermal vacuum tests and spacecraft integrated test. Rehearsal and proxy data available for software tool testing and model predictions On-orbit calibration loosely divided into early orbit operations, intensive calibration/validation, and long term monitoring CrIS/ATMS Cal/Val plans have been carefully coordinated to assure comparable results and timing In development and testing: Cal/Val tools and procedures NPP mission major objectives: To provide continuation of the group of Earth system observations initiated by the Earth Observing System (EOS) Terra, Aqua, and Aura mission To provide the operational forecasting community with pre operational risk reduction, demonstration, and validation for selected JPSS instruments and ground processing data systems. Five sensors will be flown on the NPP mission Visible Infrared Imaging Radiometer Suite (VIIRS) Cross-track Infrared Sounder (CRIP) Advanced Technology Microwave Sounder (ATMS) Ozone Mapping an profiler Suite (OMPS) Clouds and the Earth’s Radiant Energy System (CERES) Calibration and Validation demonstrate that the CrIS sensor is ready to perform its mission objectives.