Cognitive radar offers the prospect of improved performance, or alternatively, the maintenance of existing performance under more challenging conditions, by better utilising the resources the radar system has available to it. This benefit is derived from the active control of the degrees of freedom available to the radar, based on the history of previous behaviours and the associated performance achieved, knowledge of the mission and environment, and the current perception provided by received signals. Waveform diversity is one of the degrees of freedom open to cognitive radar systems. This paper describes an experimental investigation of the use of restricted bandwidth chirps, notched chirps and notched phase coded waveforms to enable a cognitive radar to coexist with a primary user of the RF spectrum
