galaxy surveys observe in redshift-space, where the peculiar velocities of galaxies can add Doppler shifts to the measured redshifts [e.g., @art:davispeebles83; @art:kaiser87]. This effect can result in errors in the inferred spatial positions of galaxies, whereby certain large-scale structures can appear to be more elongated along the line of sight than they are in reality. Therefore, before a filament finder can be applied to a sample of galaxies from a galaxy redshift survey, the redshifts first need to be converted to proper distances, which need to be corrected for the redshift-space distortions. The majority of the effects of velocities on redshift measurents can be supressed [e.g., @art:tegmark04; @art:tempel14], but for some filaments errors in the locations of the inferred spines can remain.

UV background uncertainty  {#sec:uvb}
--------------------------

As was briefly touched upon in Section \[sec:simbox\], another large uncertainty to the expected signal strength is the intensity of the UVB. For this reason, we considered three observationally driven models for the UVB. Although there is a large spread in the possible filament signal values, we use a mean value from the distribution shown in Fig. \[fig:filsigs\] calculated for each UVB to determine its effect on the overall distribution. Since some of 