Figure 4 : Solid lines represent the mean number of detectable signals as a function of the detection probability ϕ for different numbers N of emitters in the galaxy.

From: Signal coverage approach to the detection probability of hypothetical extraterrestrial emitters in the Milky Way

Figure 4

N = 1, 2, 4, 8, 16, … from bottom to top. The thick solid line is ln(1 − ϕ)−1 while the grey region in the figure indicates .