The space-time distribution characteristics of clutter under the airborne bistatic radar system are heavily dependent on the configuration of bistatic radar. For the airborne bistatic radar system

to solve the problem that the radar configuration scene is in time-varying state due to the relative motion between the carriers

the fixed ground coordinate system was constructed. By using the coordinate transformation method

the analytical expression of bistatic range sum unit and the clutter echo expression were derived

and the mathematical model of clutter in a time-invariant coordinate system was established. Then the space-time distribution characteristics of clutter under airborne bistatic radar system and the influence of bistatic radar configuration on clutter distribution were theoretically analyzed and simulated

which verified the validity of the clutter model. The simulation results show that clutter distribution is greatly different under four flight configurations

i.e.

consistent heading

parallel heading

vertical heading

and intersecting heading. The smaller the bistatic range sum is

the more the angle-Doppler trace disperses

the faster the Doppler frequency changes with the range

and the stronger the range correlation is. However

with the increase of bistatic range sum

clutter angle-Doppler trace gradually approaches

and range dependence of clutter is relatively reduced. The radar clutter model with fixed coordinate system is independent of the transceiver platform

which avoids the repeated modeling caused by the platform movement and extends the range of clutter model

which lays a foundation for the study of clutter suppression for airborne bistatic radar.