bistatic

Bistatic refers to a sensing configuration in which the transmitter and receiver are at distinct locations. This contrasts with monostatic systems, where the transmitter and receiver are co-located or share a single antenna. Bistatic arrangements are used in radar, sonar, and other wave-propagation domains.

In radar and related fields, a bistatic setup illuminates a target with a transmitter and collects the reflected signal at a separate receiver. The geometry is characterized by the bistatic angle, the angle at the target between the transmitter-target and target-receiver lines of sight. The measured range is the sum of the transmitter-target and target-receiver distances, rather than a single direct path from one point.

Bistatic configurations can be active, with a dedicated transmitter and separate receiver, or passive, where the transmitter is a non-cooperative source (such as commercial radio, television, or other radiators) and the receiver captures reflections. Passive bistatic radar, in particular, can exploit existing signals to detect objects without a dedicated illumination source.

Advantages of bistatic sensing include wider geographical coverage, potential reductions in detection risk, and diversity of illumination which can aid clutter rejection. Disadvantages include more complex geometry and calibration requirements, degraded coherent processing due to shifting phase centers, and performance that strongly depends on the bistatic angle and target aspect. Signal processing is more complicated, with potential range-Doppler ambiguities and geometry-dependent resolution.

The term can also apply to multistatic systems, where more than one transmitter or receiver participates; however, bistatic denotes the two-site case of separate transmitter and receiver.