Earthdata Forum

Posted: **Wed Feb 04, 2026 3:35 pm America/New_York**

Hi friends,

I am trying to run calibrate_viirs and getting the following error.

calibrate_viirs ifile=SNPP_VIIRS.20260201T190600.L1A.nc l1bfile_mod=SNPP_VIIRS.20260201T190600.L1B.nc

VcstCalNetcdfInputItem::readNetcdfDynamic() Failure opening LUT file: /data1/ocssw/var/viirsn/cal/OPER/VIIRS_NPP_CAL_RSB_DYNAMIC_LUT_20111122_20240107_v3.1.0.25_20230901_obpg.nc
VcstCalNetcdfInputItem::getData(iet) Failure reading netCDF dynamic file for LUT F_PREDICTED_LUT
VcstObc:: LUT initialization failure
VcstViirsCal::Granule initialization failure
Main:: Calibration initialization failure

My version:
calibrate_viirs --version
calibrate_viirs 3.2.2 (Jan 30 2025 23:46:56)

LUT directory contents after running update_luts viirsn:
ls -l /data1/ocssw/var/viirsn/cal/OPER
total 230720
-rw-rw-r-- 1 norman norman 3279059 Dec 1 17:39 VIIRS_NPP_CAL_DNB_DYNAMIC_LUT_20120121_20230520_v3.1.0.13_20220811_obpg.nc
-rw-rw-r-- 1 norman norman 76797895 Jan 16 2025 VIIRS_NPP_CAL_RSB_DYNAMIC_LUT_20111122_20250428_v3.1.0.39_20241218_obpg.nc
-rw-rw-r-- 1 norman norman 79636543 Dec 1 17:39 VIIRS_NPP_CAL_RSB_DYNAMIC_LUT_20111122_20250717_v3.1.0.42_20250410_obpg.nc
-rw-rw-r-- 1 norman norman 42363999 Dec 1 17:39 VIIRS_NPP_CAL_STATIC_LUT_v3.1.0.13_20220728_obpg.nc
-rw-rw-r-- 1 norman norman 30827371 Dec 1 17:39 VIIRS_NPP_CAL_STRAYLIGHT_DYNAMIC_LUT_20120123_20230220_v3.1.0.13_20220811_obpg.nc
-rw-rw-r-- 1 norman norman 3081795 Dec 1 17:39 VIIRS_NPP_CMN_LUT_v3.1.0.13_20220708_vcst.nc
-rw-rw-r-- 1 norman norman 257019 Dec 1 17:39 VIIRS_NPP_GEO_LUT_v3.1.0.0_20220112_vcst.nc

Any ideas about what I may be doing wrong? (It's been a while since I have processed VIIRS data, so my chances of boo boos are high.)

Thanks,
Norman

Posted: **Wed Feb 04, 2026 3:55 pm America/New_York**

I notice you have two versions of the CAL_RSB_DYNAMIC LUT in the directory.

The current operational version is:
VIIRS_NPP_CAL_RSB_DYNAMIC_LUT_20111122_20250717_v3.1.0.42_20250410_obpg.nc

Not sure if this matters, but it is a place to start.
The code my be unable to reconcile the two and falls back to a default value that does not exist?
Tommy

Posted: **Wed Feb 04, 2026 4:06 pm America/New_York**

Hi Tommy,

I deleted /data1/ocssw/var/viirsn/cal/OPER/VIIRS_NPP_CAL_RSB_DYNAMIC_LUT_20111122_20250428_v3.1.0.39_20241218_obpg.nc and ran the calibrate_viirs command again but get the same results (i.e. it's looking for /data1/ocssw/var/viirsn/cal/OPER/VIIRS_NPP_CAL_RSB_DYNAMIC_LUT_20111122_20240107_v3.1.0.25_20230901_obpg.nc ).

Norman

Posted: **Wed Feb 04, 2026 4:12 pm America/New_York**

I just tried this.

ln -s VIIRS_NPP_CAL_RSB_DYNAMIC_LUT_20111122_20250717_v3.1.0.42_20250410_obpg.nc VIIRS_NPP_CAL_RSB_DYNAMIC_LUT_20111122_20240107_v3.1.0.25_20230901_obpg.nc

Now calibrate_viirs appears to work. Hope I'm not breaking anything down the line.

Norman

Posted: **Wed Feb 04, 2026 4:36 pm America/New_York**

try editing this file: SeaDAS/ocssw/share/viirs/npp/instrument_defaults.par

Code: Select all

static_lut_file=$OCVARROOT/viirsn/cal/OPER/VIIRS_NPP_CAL_STATIC_LUT_v3.1.0.13_20220728_obpg.nc
rsb_dynamic_lut_file=$OCVARROOT/viirsn/cal/OPER/VIIRS_NPP_CAL_RSB_DYNAMIC_LUT_20111122_20240107_v3.1.0.25_20230901_obpg.nc

dnb_dynamic_lut_file=$OCVARROOT/viirsn/cal/OPER/VIIRS_NPP_CAL_DNB_DYNAMIC_LUT_20120121_20230520_v3.1.0.13_20220811_obpg.nc
straylight_lut_file=$OCVARROOT/viirsn/cal/OPER/VIIRS_NPP_CAL_STRAYLIGHT_DYNAMIC_LUT_20120123_20230220_v3.1.0.13_20220811_obpg.nc

cmn_lut_file=$OCVARROOT/viirsn/cal/OPER/VIIRS_NPP_CMN_LUT_v3.1.0.13_20220708_vcst.nc
geo_lut_file=$OCVARROOT/viirsn/cal/OPER/VIIRS_NPP_GEO_LUT_v3.1.0.0_20220112_vcst.nc

polar_wander_file=$OCVARROOT/common/polar_wander.ascii
leapsec_file=$OCVARROOT/common/tai-utc.dat

terrain_path=$OCDATAROOT/viirs/dem/
xml=$OCDATAROOT/viirs/npp/viirs_product.xml

Posted: **Wed Feb 04, 2026 5:20 pm America/New_York**

Yes that works too which is just as well since some other process deleted the symbolic link I made earlier.

Thanks Tommy.

Norman

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