This would be really easy by correlating signal strength measurements from several towers. Then, an analysis of these data would reveal unusual patterns that d

This would be really easy by correlating signal strength measurements from several towers. Then, an analysis of these data would reveal unusual patterns that differ from what would result with the common isotropic antenna. This kind of correlation is already in use by mobile networks to narrow the location of emergency calls from handsets that are not sending GPS or other positional data.