Reproducing L2 processing for VIIRS and MODIS

[nhtjs]

Hello,
I'm trying to reproduce the processing of Rrs for VIIRS and MODIS. While the Rrs values computed with OCSSW are very close to the one downloaded from OBPG, I have the following differences in my global metadata:

  + For both satellites I have differences in processing_control_input_parameters_icefile:
    OBPG uses the SST file: N2017324_SST_OIV2AV_24h.nc
    while getanc from SeDAS will get a sea ice file: N201732400_SEAICE_NSIDC_24h.hdf
    => Are SST and SeaIce files interchangeable when there is likely no sea ice (working in Hawaii area) ?
  + for MODIS only I have differences in the processing_control_input_parameters_xcalfile:
    SeaDAS: xcal_modisa_axc_oc_v1.19d
    OBPG: xcal_modisa_axc_oc_v1.6d
                Is the v1.19d an improved xcal file ?

I was wondering if you had recommendations on which parameters to keep as it seems that SeaDAS is at a more advanced version 9.3.0-044d4967 vs 9.2.0-V2017.0.3 for 2018.0/L2/V2017321224200.L2_SNPP_OC.nc and 9.2.1-V2018.0.3 for 2018.0/L2/A2017324235500.L2_LAC_OC.nc .
Best,
Nils

[OB.DAAC - SeanBailey]

Nils,
Both seaice ancillary inputs are derived from the same source, any difference is due to the way the fields are stored/interpolated and should minor.  It's also just used for flagging, and no..there is not much seaice near Hawaii :grin:

The xcal files are updated, but in between reprocessing events the newer versions will replicate the values for the past, so the there is no difference in the two for the scene in question.

Smae goes for the l2gen versions... mostly :wink:

Sean

[nhtjs]

Thank you for the clarifications Sean!
Best,
Nils