understood such that asteroids have been used for calibrating detectors and for determining beam shapes. The thermal model used for describing the submillimetric emission by asteroids is the same extension of the Wright & Odenwald model as for rocky planets. However, additional features that had to be incorporated was the beamed emission due to surface roughness. Furthermore, in the system of differential eqns. (\[eqn\_B\_def\]) - (\[eqn\_R\_def\]) terms $W$ and $R$ were neglected due to the absence of atmospheres in asteroids.

Information about the diameter and albedo was derived using the HG-magnitude system in case of asteroids for which those quantities are unknown, otherwise literature values were taken [from @2000dba..book.....M and IAU’s [*Minor Planet Centre*]{} [^4]]. For the description of the rotation period, an empirical relation that expresses the rotation period as a function of mass was used in the cases where the rotation period is unknown. The brightest sources include Ceres ($T_\mathrm{Ceres}=19.7~\umu\mbox{K}$), Pallas ($T_\mathrm{Pallas}=7.2~\umu\mbox{K}$), Vesta ($T_\mathrm{Vesta}=6.7~\umu\mbox{K}$) and Davida ($T_\mathrm{Davida}=2.1~\umu\mbox{K}$). The temperatures stated are antenna temperatures measured in the $\nu=100$ GHz-channel at the brightness maximum.

Our simulation shows that the number of detectable asteroids is overestimated by @2002NewA....7..483C, who did not take the expected observation geometry and detector response into account. 