MiRS currently has four surface types: 0=ocean(oc), 1=sea ice(ic), 2=land(ld), 3=snow(sn)

      For snow and ice, please select three north hemisphere winter dates to get the covariance matrix.

      For ocean and land, please select four dates in each season to get the covariance matrix.

Note: for ocean, random wind speed were used in colocNWPwRad.f90 to make emissivity over ocean more variable

Given MiRS has been run at least till NWP step and the FMSDR files are generated,
         following are steps to generate covariance matrix

Step 1: FilterScenes
   INPUT: NWP* files from nwp step, the files are typically under data/TestbedData/DynamicData/nwp_analys
   OUTPUT: Scene_ic_gpm_gmi_ecmwf.dat

Step 2: Generation
   covMatrx_sfc_ice.pro

Step 3: Merge
   mrgCovMatrxFiles.pro

