
Figure 1: Schematic response of two-way Doppler tracking to a GW. The Doppler exhibits three
pulses having amplitudes and relative locations which depend on the GW arrival direction, the
two-way light time, and the wave’s strain amplitude and polarization state. The sum of the three
pulses is zero, so the pulses overlap and partially cancel when the characteristic time of the GW
pulse is comparable to or larger than the light time between the earth and spacecraft.