The coefficients represent a linear regression of SST on brightness temperature. In practice, regression is based on model brightness temperatures derived from an ensemble of atmospheric profiles using a Radiative Transfer Model. The coefficients used for ATSR processing are based on RAL model RADGEN.
The following steps are involved in coefficient derivation:
Generate ensemble of atmospheric profiles
Profile set should be statistically representative
Run radiative transfer model (RADGEN) to derive brightness temperatures for each profile
Derive regression coefficients of surface temperature vs. brightness temperatures
Impose constraints at this stage if stratospheric aerosol robust coefficients required
The coefficient derivation depends on an ensemble of atmospheric profiles, RADGEN version and auxiliary data.
For more detailed information on coefficients retrieval click here .
Original coefficients based on scheme having 10 across-track bands.
Aerosol robust coefficients developed by C.J.Merchant (This was done in order to generate coefficients insensitive to the presence of stratospheric aerosol)
Revised scheme for ATSR processing uses new treatment of stratospheric aerosol (Merchant et al 1999)
New across-track banding scheme
Earlier versions used a scheme of 10 bands across the swath (Zavody et al 1995)
5 bands from center to edge
New scheme with 76 bands incorporated to reduce discontinuities at band edges
38 bands from center to edge
Corrects known errors in derivation of ATSR-2 coefficients used in V310 to V321.