Simulation based study of Aircraft Detection in Chaff Environment using Radar Techniques

In this paper, a framework has been implemented for simulating the radar signal returned from the deployment and subsequent growth of chaff in the presence of multiple aircraft. The growth and distribution of chaff released from aircraft is found to follow the wing-tip vortices of aircraft. Furthermore, the returned radar signal from the targets (aircraft and chaff) have been used with various Doppler radar techniques to detect the aircraft in the chaff environment. The transmit signal used for simulating the return from chaff and aircraft is a non-linear frequency modulated signal at X-band. The transmit signal is shaped based on linear as well as nonlinear bandwidth. The returned signals are processed to remove the impact of chaff and detect the aircraft based on moving target indicator and Doppler processing. Subsequently, the detection of targets is done using cell averaging constant false alarm rate and the unambiguous range and velocity have been determined with the use of staggered pulse repetition frequencies. Graphical representation of the Chinese remainder theorem is used to increase the unambiguous range and velocity and resolve range and Doppler velocity ambiguities from multiple PRFs. The simulation results show great accuracy in detection of aircraft beyond 100 km with velocities higher than 900 km/hr and also reduce the impact of chaff.