Waveform evolution as a function of observing time. Individual waveforms are plotted over the input A-channel PSD (solid, red curve), noise (constant, black curve stretching across the frequency window) and residual (dashed, blue curve) curves. The top graphs show a single 1.5-month (left panel) and 3-month (right panel) catalogue waveform, in green. The bottom panels show, in total, three 6- and 12-month catalogue waveforms, two of which did not appear in any earlier catalogue. All injected signals in this frequency window were recovered in a 6- and 12-month analysis.