CLAVR-x Ancillary Data

CLAVR-x Ancillary Data

All of the CLAVR-x ancillary data is made available through the data directory whose path is specified in the clavrxorb_default_options file
which is described below. For reference, we will refer the main ancillary data directory as $CLAVRX_ANCIL_DATA

The static ancillary data is available in data tarballs located at the same ftp directory as the code. These include one for the lookup tables (luts), one for the clear composites and one for everthing else. You should untar these tarblls within $CLAVRX_ANCIL_DATA.

Description of ancillary data directories.

$CLAVRX_ANCIL_DATA/avhrr_data

This directory holds the instrument and algorithm constant files for each satellite. For example, the files for NOAA-16 are called avhrr_16_instr.dat and avhrr_16_algo.dat.

$CLAVRX_ANCIL_DATA/clr_comp_v01

This directory holds the clear-sky composities of the channel 1 reflectance and of the ndvi. One file exists for each day of the year.

$CLAVRX_ANCIL_DATA/luts

This directory holds three sub-directories (/aerosol, /cld and /clr_ocn). These directories hold the lookup tables (luts) used for aerosol, cloud and clear-sky ocean modeling.

$CLAVRX_ANCIL_DATA/pfast

This directory holds the PFAST Radiative Transfer Model (RTM) coefficients.

$CLAVRX_ANCIL_DATA/sfc_data

This directory holds the ancillary files concerned with surface properties. It contains the NCEP minimum air temperature climatology, the OISST 30 year climatology. This directory also contains the University of Maryland land cover, land, volcano and coast masks, SEEBOR surface emissivity analysis, and the digital elevation. It also contains the data necessary to produce the equal angle and area gridcell orbital files.

$CLARVX_ANCIL_DATA /gfs_archive

This directory contains or points to the NCEP/GFS fields. CLAVR-x expects to see 12 hour forecasts from each 6 hour model cycle. Note, CLAVR-x requires that the GFS files be converted to HDF4 using the convert_grib_hdf.f90 code. This code is included in the CLAVR-x distribution. And, if the GFS files names differ from what CLAVR-x expects, CLAVR-x will have to be modified.

$CLAVRX_ANCIL_DATA/ncep-reanalysis

This directory contains or points to the NCEP Reanalysis data. This data is described here: http://www.cdc.noaa.gov/cdc/data.ncep.reanalysis.html

$CLAVRX_ANCIL_DATA /oisst_analysis

This directory contains or points to the location of the Reynolds OISST data which is obtained here http://www.emc.ncep.noaa.gov/research/cmb/sst_analysis/

Additional Comments

Remember CLAVR-x can use the GFS or the NCEP reanalysis data. If no data is chosen, then only observations, geolocation and navigation data can be calculated. If no NWP data is used, algorithms and orbital data will not be processed.

The GFS, NCEP and OISST archives are typically very large. If these data reside outside of $CLARVX_ANCIL_DATA, be sure to link these data to the expected directories under $CLAVRX_ANCIL_DATA.