How does FLUXES work?

In this section we will discuss the actual calculations performed by FLUXES to produce its position and flux output. This depends somewhat upon the planet for which information is requested. For Mars, the following steps are performed:

• Topocentric and Geocentric R.A. and Dec positions, distances and airmass are calculated
• The solid angle subtended by the planet is calculated
• The brightness temperature at 350$\mu$m (857 GHz), T_b857, is calculated by linear interpolation from 40-day interval values, from either Wright's original model or the rotating cratered asteroid model, depending upon the date (see section )
• The brightness temperature at 3.3mm (90 GHz), T_b90, is calculated following the simple relation given by Ulich (1981, A.J., 86, 1619)
• A logarithmic interpolation between T_b857 and T_b90 calculates the brightness temperature for each filter wavelength
• The brightness temperature is converted to integrated and beam-corrected flux densities.

Alternatively, for Jupiter, Saturn, Neptune and Uranus, the following calculations are performed:

• Topocentric and Geocentric R.A. and Dec positions and airmass are calculated
• The solid angle subtended by the planet is calculated
• The brightness temperature for the relevant planet(s) for each filter is given by a look-up table as described in section
• The brightness temperature is converted to integrated and beam-corrected flux densities.

Finally, for Mercury, Venus, the Sun and the Moon, only the first step is performed:

• Topocentric R.A. and Dec positions, distances and airmass are calculated

Below we will discuss the individual calculations in more depth.