Something i came across while reading some material, Radars Vs Anti-Radiation Missiles and Radars Vs Stealth.
Bistatic and Multistatic Radars
Any radar, for example, a continuous wave radar, in which electrical isolation requires that the transmitting antenna be physically separate from the receiving antenna might be regarded as of bi-static type. Here, however, the only systems to be considered are those in which the transmitter and receiver are separated by appreciable distances.
This technique, hitherto hardly used, is presently being examined with renewed interest with a view to wider employment because of the spread of:
1. More and more effective radar jamming systems;
2. Anti-radiation missiles (ARMS);
3. Stealth aircraft.
When transmitter and receiver are far apart, a jamming signal must be radiated over a very broad angle in order to have a high probability of interfering with reception. However, in this way the jamming power actually radiated
toward the receiver is substantially reduced, which in turn reduces the effectiveness of the jamming.
The advantages of a bi-static radar network against ARMS may easily be inferred. The separation of transmitter and receiver leads to the establishment of radar networks consisting of M transmitters serving N receivers (N>M). These are multi-static radars. In these networks, the transmitters, widely spaced, may radiate sequentially, disorienting ARM receivers.
Separation between transmitter and receiver may be beneficial also for stealth aircraft detection. In fact, because these aircraft are capable of reducing their RCS mainly in the direction of arrival of the electromagnetic wave, if a stealth aircraft is illuminated from one direction, and the scattered radiation observed from another direction, the low visibility characteristic is substantially degraded.
Filippo Neri, Introduction to Electronic Defense Systems, Ch. 2, Pages 125-126