The 2024 brightness temperature spectra gives lower values than the Legacy model.
The difference is on the order of 5% from 70 to 210 GHz but increases to
10% at from 210 to 230 GHz and above 300 GHz.
A Saturn's atmospheric line makes the offset bigger in the 230-300 GHz range (30% offset around 270GHz).
In CASA the choice was made not to use Saturn as a flux calibrator (because the rings make the modelling of an average brightness temperature difficult)
Like Jupiter, Saturn is in general not used as a flux calibrator, so the impact of the new model should remain limited.
Figure 6:
Comparison of the brightness temperature of Mars at 80 GHz as a found by the ASTRO Legacy (black line) and the CASA models (red line). Top panel shows the expected temperature behavior over a decade, while middle and bottom panels show zoom on a period of one year and one month, respectively.
![\includegraphics[width=14cm]{Mars-evol-80.eps}](img23.svg) |
Figure 7:
Same as Fig. FigMarsT80 but for 150 GHz.
![\includegraphics[width=14cm]{Mars-evol-150.eps}](img24.svg) |
Figure 8:
Same as Fig. FigMarsT80 but for 230 GHz.
![\includegraphics[width=14cm]{Mars-evol-230.eps}](img25.svg) |
Figure 9:
Same as Fig. FigMarsT80 but for 360 GHz.
![\includegraphics[width=14cm]{Mars-evol-360.eps}](img26.svg) |