SST CCI Auxiliary Datasets

These auxiliary datasets are used in the generation of SST CCI ATSR and AVHRR products.  Each set of files is contained in a separate tar archive and their application is briefly described below.  For more information on the SST CCI algorithms please refer to the publicly available Algorithm Theoretical Basis Document.

Retrieval coefficients:

ATSR_Retrieval_Coeffs.tar

These files contain the retrieval coefficients used to retrieve SST for the ATSR instruments.  These are banded by total column water vapour and viewing angle.  Coefficients are provided for all applicable retrievals - nadir two channel (n2), nadir three channel (n3), dual-view two channel (d2) and dual-view three channel (d3).

Spectral response functions:

AATSR_SRF.tar, ATSR2_SRF.tar, ATSR1_SRF.tar, AVHRR_SRF.tar

These files contain the spectral response functions for each channel of each ATSR and AVHRR instrument.  Note that all the AVHRR instruments are bundled in a single tar file including NOAA6 - NOAA19 and MetopA.  All files are in plain text format containing two columns, the first is the wavelength and the second the filter response at that wavelength.

Probability Density Functions:

ATSR_PDFs.tar, AVHRR_PDFs.tar

These are netCDF format files which include spectral and textural PDFs for cloudy conditions and textural PDFs only for clear-sky conditions.  Dimensions are defined also as variables which give metadata describing their bounds and bin widths.  The PDFs themselves are multi-dimensional variables constrained by the definitions of their given dimensions.

Sea Surface Emissivity:

ATSR_sse.tar, AVHRR_sse.tar

Within SST CCI, the sea surface emissivity is calculated offline, and then passed to RTTOV for use within the radiative transfer calculation (by-passing the internal RTTOV surface emissivity model).  These files are in ascii format and constructed in such a way as to be readable by RTTOV.

Level 4 Land/Sea Mask

mask_ostia20Tnolakes.nc

This is a netCDF format file containing the land/sea mask used when generating Level 4 data on the OSTIA grid.