From my understanding, and correct me if I'm wrong, the bistatic radar equation assumes that the transmitter and the receiver are separated by a distance $L$, and that the transmitter and receiver are static, while the target is moving at a distance $R_r$ from the receiver and a distance $R_t$ from the transmitter. $$P_r = {{P_t G_t G_r \sigma \lambda^2}\over{{(4\pi)}^3 R_t^2R_r^2}}$$
Hence my question, does the bistatic radar equation is different when the transmitter, the receiver, and the target are all moving? Does the equation change only when one want to consider Doppler effect?