A special case has been reserved for the planet Mars, since it offers an option to fine-tune your calibration. The Miriad task marstb will interpolate a table of calculated values to a given frequency and date in the range 1999-2014, used as follows:
To find the model value:
% marstb epoch=08mar02 freq=95.0 Brightness temperature at 95.0 GHz: 187.675
to find the value of brightness temperature used in your data, read the variable PLTB using either the varplt log option or uvio if it is in your distribution, e.g.
% varplt vis=ct007.mars_88GHz.2006nov12.1.mir yaxis=pltb log=tblogor
% uvlist vis=ct007.mars_88GHz.2006nov12.1.mir options=var,full | grep pltb
pltb 206.6920013
To change the value of PLTB in your file, use uvputhd (makes new file):
% uvputhd vis=ct007.2008mar02_3mm.mars.1.mir hdvar=pltb varval=187.675 \
type=r out=ct007.2008mar02_3mm.mars.1.mir_fixed
This is actually an example where puthd should work just as well:
% puthd in=ct007.2008mar02_3mm.mars.1.mir/pltb value=187.675 type=real
The model values are disk-averaged Planck brightness temperatures from the Caltech Thermal Model. As Mel noted, Mars isn't always a disk and dust storms can't be accomodated in this model, but the Caltech model values should be more reliable than CARMA's previous model (10% different in the example above from a month ago).