Dynamic RCS Modelling and Simulation of Non- Uniformly Distributed Chaff Fibers in Space

In Modern warfare scenario, thin conducting chaff fibers with very high aspect ratio are used as passive electronic countermeasure. Radar Cross Section (RCS) of chaff cloud is an important parameter deciding its performance as electronic countermeasure. The chaff cloud is a dynamic target as when it is dispensed, it blooms in the atmosphere depending upon the atmospheric conditions and the platform speed at that time. In actual scenario, the dipoles are distributed in a chaff cloud in an irregular manner, i.e. they may have different densities at different places and may have irregular shape. It is very complex task to get insight in the dynamic RCS response of these irregular shape clouds. For this reason, the regular shaped chaff cloud shape i.e. spherical, cubical, plume, cylindrical etc were studied for nonuniform distribution of chaff fibers. A simple approach is taken to study the screening effect of chaff cloud having different dipole density distribution in chaff cloud and its effect on overall dynamic RCS of chaff cloud. In this approach, the regular shaped chaff cloud is divided into N parts having different dipole distribution densities in each part. These N parts were studied individually based on screening effect and the dynamic RCS response was evaluated for the whole cloud. A comparison has been made for uniform as well as non -uniform chaff cloud dynamic RCS response. Comparison of RCS for different regular shaped chaff cloud was also made to see the effect of chaff cloud shape on dynamic RCS response. This study finds the importance in the effectiveness of chaff cloud dynamic RCS response during initial engagement of missile and the aircraft.