Saturday, November 13, 2010

Bistatic Radar

A bistatic radar is a radar system composed of a transmitter and a receiver, set apart at a distance which is comparable to the expected target distance. In other words, a bistatic radar consists of separately located transmitting and receiving sites. The transmitter and receiver share a common antenna, which is called a monostatic radar system. In some configurations, bistatic radars are designed to operate in a fence-like configuration, detecting targets which pass between the transmitter and receiver, with the bistatic angle near 180 degrees. This is a special case of bistatic radar, known as a forward scatter radar, after the mechanism by which the transmitted energy is scattered by the target. In forward scatter, the scattering can be modeled using Babinet's principle and is a potential countermeasure to stealth aircraft as the radar cross section (RCS) is determined solely by the silhouette of the aircraft seen by the transmitter, and is unaffected by stealth coatings or shapings.

the bistatic radar is mainly used for weather radar and its technology has been in use for several years at the Institute of Atmospheric Physics at the German Aerospace Center.This system is also of some importance in militar applications. The so called "semi-active" missile control system, as used in the missile unit "HAWK", is practically a bistatic radar. By receiving the side lobes of the transmitting radars direct beam, the receiving sites radar can be synchronized. If the main lobe is detected, an azimuth information can be calculated also. A number of specialized bistatic systems are in use, for example, where multiple receiving sites are used to correlate target position.

A multistatic radar system is one in which there are at least three components - for example, one receiver and two transmitters, or two receivers and one transmitter, or multiple receivers and multiple transmitters. It is a generalisation of the bistatic radar system, with one or more receivers processing returns from one or more geographically separated transmitters.