Integrating Changes to JPSS Cross-Track Infrared Sounder (CrIS) SDR Algorithm using the Algorithm Development Library (ADL) Vipuli Dharmawardane 1, Bigyani Das 1, Valerie Mikles 1, Walter Wolf 2 1 I. M. Systems Group, 2 NOAA/NESDIS/STAR Abstract The Cross-Track Infrared Sounder (CrIS) is a Fourier transform spectrometer on board Suomi National Polar-Orbiting Operational Environmental Satellite System Preparatory Project satellite (S-NPP). CrIS provides measurements of Earth view interferograms with 1305 spectral channels in three infrared spectral bands at 30 cross-track positions, each with a 3 x 3 array of field of views. Joint Polar Satellite System 1 (J1) is the second generation spacecraft within NOAA’s next generation polar-orbiting satellites that is planned to be launched in Having a similar instrument suite to S-NPP, J1 will utilize algorithms developed for S-NPP. The Interface Data Processing Segment (IDPS) has produced calibrated and geolocated truncated resolution spectra in the form of Sensor Data Records (SDR) in the S-NPP era, and currently revisions to the CrIS SDR algorithm are underway to support production of the full resolution J-1 SDRs within the IDPS. ADL is the test system that mimics IDPS and is used for testing, troubleshooting and integrating algorithm updates. In this poster we discuss the process that we use for testing the pre-operational full spectral resolution algorithm for product accuracy in the ADL environment before it is submitted to the ground project Data Products Engineering Services (DPES) for the unit testing. The testing, integration and the change request package preparation steps will be presented. CrIS Overview ADL is developed by Raytheon ADL environment is used to develop and debug the algorithm code items on computing platforms outside of IDPS ADL framework mimics the IDPS processing system and when an algorithm code item is linked to the ADL framework it executes as if it were inside the IDPS When same inputs are given the algorithm code in the ADL environment produces a result equivalent (except for differences due to round off errors, different compilers etc.) to a result produced by the code running in the IDPS environment ADL Framework IO Software development File System and testing Based IDPS Operational Framework IO Integrated Relational Algorithm DB Based Algorithm DB Based Input → Algorithm Processing software → Output CrIS SDR Algorithm ADL and IDPS Framework References Full Resolution/Normal Resolution RDRs Common Inputs Resolution dependent Inputs Binary Outputs Resolution Dependent executable HDF5 outputs Resolution dependent outputs Data Flow for CrIS Algorithm Testing the Algorithm and Discussion of Results J1 software changes STAR AIT Role in the Algorithm Change Procedure JPSS-1 (J1) is the second spacecraft within NOAA’s next generation polar-orbiting satellites, succeeding S-NPP. CrIS has used nominal resolution data packets during the S-NPP era and currently revisions to the CrIS sensor data records (SDR) algorithm are underway to support production of the full resolution J1 SDRs. The S-NPP instrument has already transitioned from normal spectral resolution mode to the full spectral resolution mode and continue to produce normal resolution SDRs by truncating the Mid-Wave and Short –Wave band data into normal resolution interferograms. The J1 code is developed and designed to produce both normal and full resolution SDRs concurrently if required. Under the Input (“I”) - Processing(“P”) - Output(“O”) model of ADL and IDPS, the I/O data structures, including the array sizes, are specified with XML files. This design feature is employed to produce two different executables using the same source code but different XML files, that produce normal and full resolution SDRs. Summary of the different input RDRs that can be processed, and the corresponding output files produced by the two J1 executables, is given in the block diagram below. Pre-operational full spectral resolution algorithm is tested by the STAR Algorithm Integration Team (AIT) for product accuracy in the ADL environment before it is submitted to the ground project Data Products Engineering Services (DPES) for the unit testing. Additionally STAR AIT group works with Algorithm team, DPES, and Raytheon on algorithm implementation into ADL and leads reviews to ensure project meets requirements and remain on schedule. NOAA Satellite Conference: Preparing for the Future of Environmental Satellites: April 27-May 1, 2015, Greenbelt, MD Corresponding Author: Main objectives of the SDR algorithm Pre-process incoming data packets  Load and sort data  Convert interferograms to spectra Convert scene measurements into calibrated spectra Evaluate the associated error CrIS SDR processing flow Normal Resolution Executable Full Resolution Executable Normal Resolution RDR Full Resolution RDR Full Resolution SDR Normal Resolution SDR Calibration Updates for J1 Following calibration algorithm modules were updated  Interferogram to raw spectra conversion  Self-apodization correction  Spectral resampling  Post-calibration filter  Radiometric calibration  NEdN calculation New algorithm was tested in the ADL framework In addition to performing a functional test output files are examined to verify results Typically results are compared against outputs produced using a version of the software compiled using the original code (baseline) Results are compared to determine if the changes are as expected Different calibration orders and coefficients are used for the two resolutions via a resolution dependent input Processing Coefficient Table (PCT) Geo- location Pre-Process IGM to Spectrum FFT FCE Handling Spectral Resample Post Calibration BPF Radiometric Calibration Nonlinearity Correction ILS Correction Science RDR SDR Spectral Calibration BandIFGM number of bins User Grid Range (cm -1 ) Spectral Resolution (cm -1 ) Maximum Optical Path Difference (cm) Number of SDR Channels LWIR866 (866) (0.625)0.8 (0.8)713 (713) MWIR530 (1052) (0.625)0.4 (0.8)433 (865) SW202 (799) (0.625)0.2 (0.8)159 (633) A typical cross-track scan sequence consists of 34 interferometer sweeps or Field of Regards (FOR), including 30 Earth Scenes (ES), 2 Deep Space (DS) and 2 Internal Calibration Target (ICT) measurements. Sweeps are performed in both forward and reverse directions. CrIS collects interferograms from 9 field of views (FOV) in a 3x3 array configuration at each position on field of regard. One scan of the CrIS will take about 8 seconds. CrIS Measurement Sequence CrIS is a Michelson interferometer. It provides measurements of earth view interferograms with 1305 spectral channels in three infrared spectral bands. CrIS S-NPP (J1) Spectral Characteristics A typical Interferometer measurement for the Long Wave band slew1234… slew31 slew …. FOR index…. 8-second scan DS ICT next scan F R F R F R R F R F Figure above is a comparison of radiance for normal resolution and full resolution spectra for long-wave band produced using the new J1 software and the baseline code Calibration software was improved for full resolution processing Different calibration orders and coefficients are used for the two resolutions via a resolution dependent input Processing Coefficient Table (PCT) Comparison of full resolution and baseline (normal) resolution results for all 9 FOVs for FOR =1 for the mid wave band 1.Joint polar satellite system (JPSS) common ground system (CGS) IDPS ADL Software users manual, Raytheon Company 2.Joint Polar Sattelite System (JPSS) Cross Track Infraread Sounder (CrIS) Sensor Data Records (SDR) Algorithm Theoretical Basis Document (ATBD) NOAA/STAR CrIS SDR Team 3.Yong Han et al, Suomi NPP CrIS measuremets, sensor data record algorithm, calibration and validation activities and record data quality, Journal of geophysical research: Atmospheres, Vol 118, 12, , 748 Full Resolution Baseline