negligible within the standard deviations of the distributions. We assume these values to be representative for typical filaments and we note that the difference in the resulting filament signal strengths for the two extreme models is only a factor of 3. For further estimates of the detectability, we consider both extreme cases: $\delta T_{\rm b} = 2\times10^{-7}$ K from as the lower limit and $\delta T_{\rm b} = 6\times10^{-7}$ K assuming as the upper limit.

Observational strategy {#sec:obsstrat}
======================

In order to maximize the chance of a detection, it is essential to first determine where on the sky the best candidate filaments can be found. The only resource available to find target filaments are the positions of the galaxies detected beforehand. In the same way that we determined filament signals from the galaxy catalogue of the simulation in Section \[sec:simfil\], we propose to use galaxy surveys to first determine the locations of the filament spines and then integrate the emission around these spines to obtain a signal.\
In this Section we apply this strategy to existing galaxy surveys to determine how many filaments are accesible to the SKA. We then use the average filament signals obtained in Section \[sec:simfil\] to 