ASSISTT Team,

This delivery package is prepared for ADR-11194 / CCR-7603 and aims to enhance the CrIS SDR algorithm to mitigate the impact of Neon lamp misfiring on-orbit. The NOAA-21 CrIS encourntered its first Neon lamp misfiring anomaly on March 2, 2025. The effects of this anomaly persisted for approximately seven orbits until the subsequent successful neon lamp activation. The instrument returned to nominal operation through self-recovery on March 3, 2025. This algorithm code change with a PCT update is critical for both the NOAA-21 CrIS and the future JPSS-3 and JPSS-4 missions, since they use Neon lamps manufactured by the same vendor.

The algorithm code change includes three main components, 1) Use of the median metrology laser value as default provided in the NOAA-21 CrIS PCT table, 2) Correction of spectral alias unfolding process, and 3) Update of CrIS quality flag properly when the default metrology laser wavelength was used.

The CrIS Science team requested that this algorithm change be included in the IDPS Mx13 patch between May and August 2025.

Test datasets were selected to have 10 NOAA-21 CrIS RDR granules acquired during the Neon lamp anomaly on March 2, 2025. Contents of this package include:

1) Modified Mx12 ADL files (5 headers and 3 source files):

ProSdrCrisGbl.h
EngineeringCalibrationRecord.h
ScienceDataProcessor.h
ScienceDataRecordStatus.h
Spectra.h

ScienceDataProcessor.cpp
Spectra.cpp
CrIS_SDR.cpp

2) Updated NOAA-21 CrIS PCT file:

66049ee4-6a4c4-990a7514-3ad799cc.asc
66049ee4-6a4c4-990a7514-3ad799cc.CrIS-FS-SDR-CC_j02_20250416000000Z_20190501000000Z_ee00000000000000Z_PS-1-O-CCR-7603-LE-PE_all-_all_all-_ops.bin

3) Test datasets

   a) NOAA-21 CrIS RDRs (10 granules)
      
      Granule IDs:
      (0,0): "CRIS-SCIENCE-RDR:J02004216112542:A1",
      (1,0): "CRIS-SCIENCE-RDR:J02004216112862:A1",
      (2,0): "CRIS-SCIENCE-RDR:J02004216113182:A1",
      (3,0): "CRIS-SCIENCE-RDR:J02004216113502:A1",
      (4,0): "CRIS-SCIENCE-RDR:J02004216113822:A1",
      (5,0): "CRIS-SCIENCE-RDR:J02004216114142:A1",
      (6,0): "CRIS-SCIENCE-RDR:J02004216114462:A1",
      (7,0): "CRIS-SCIENCE-RDR:J02004216114782:A1",
      (8,0): "CRIS-SCIENCE-RDR:J02004216115102:A1",
      (9,0): "CRIS-SCIENCE-RDR:J02004216115422:A1"

   b) NOAA-21 CrIS SDRs (2 granules of SCRIF and GCRSO product generated with the algorithm change)

      GCRSO_j02_d20250302_t1816249_e1816547_b11966_c20250416222241684762_ADu_ops.h5
      GCRSO_j02_d20250302_t1816569_e1817267_b11966_c20250416222303792359_ADu_ops.h5
      SCRIF_j02_d20250302_t1816249_e1816547_b11966_c20250416222241666880_ADu_ops.h5
      SCRIF_j02_d20250302_t1816569_e1817267_b11966_c20250416222303782199_ADu_ops.h5
      
   c) Common inputs, auxillary data, and baseline outputs are included.

Please feel free to contact me (kun.zhang@noaa.gov) if you have any questions.

Kun Zhang
04/16/2025
