multisite (multistatic) radar
One of important tendencies in radar development is the growth of the number of channels for the increase of volume and quality of radar information. During the last years, a new direction of multichannel radar development is discussed iontensively in English-language literature: the so-called “MIMO radar” (MIMO – Multiple Input-multiple Output).
The method and the term “MIMO” were borrowed from communications where the MIMO method turned out to be very effective because it permits increasing significantly the throughput of communication channels.
In foreign published works MIMO radars are diveded into two classes: 1) with colocated antennas (and coded signals) and 2) with widely separated antennas, the so-called “Statistical MIMO radars”.
MIMO radars with colocated antennas and coded signals represent a new and prospective direction of the radar development. The most important feature of those radars is the sharp increase of the number of degrees of freedom. This determines many important advantages: better angle resolution and lower sidelobes of antenna patterns, parameter identifiability of greater number of unresolved targets, better adaptation capability including the possibility of adaptive beamforming of transmitter antenna arrays. Besides, such radars can provide effective target search in a wide sector without space scanning.
The concept of MIMO radar with spatially diverse, widely separated antennas (“Statistical MIMO radar”) contains nothing new. Such radars are a particular case of multisite (multistatic) radar systems. Most “new” results concerning “Statistical MIMO radars” were obtained under more general conditions and published many years ago.
Having borrowed the MIMO method from communications, the authors of the “Statistical MIMO radar” applied this method to radar without studying existing achievements in radar theory and practice and without taking into account essential differences between radar and communications. Such an approach has led to serious errors, which are discussed in the paper.