Sadist-2 coefficients

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 .



Sadist versions - coefficients used

v100 to v303 coefficients

Original coefficients based on scheme having 10 across-track bands.


v310 to v321 coefficients

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


v322 coefficients

Corrects known errors in derivation of ATSR-2 coefficients used in V310 to V321.