In this chapter, the focus is on the use and control of degrees of freedom in the radar illumination pattern and presented examples to highlight the value of properly utilizing degrees of freedom. It has been shown that by coordinating the transmission of Golay complementary waveforms in time (or exploiting waveform agility over time) according to carefully designed biphase sequences, and pulse trains whose ambiguity functions have desired properties can be constructed. It has also been shown that by combining Alamouti coding and Golay complementary property unitary polarization-time waveform matrices that make the full polarization scattering matrix of a target available for detection on a pulse-by-pulse basis can be constructed. Looking to the future, unitary waveform matrices as a new illumination paradigm that enables broad waveform adaptability across time, space, frequency and polarization.

Inspec keywords: radar polarimetry; electromagnetic wave polarisation; matrix algebra; Golay codes; electromagnetic wave scattering; radar tracking; radar signal processing

Other keywords: complementary waveforms; ambiguity functions; sidelobe suppression; Golay complementary property; pulse-by-pulse basis; broad waveform adaptability; target detection; biphase sequences; radar polarimetry; degrees of freedom; full polarization scattering matrix; Golay complementary waveforms transmission; Alamouti coding; unitary waveform matrices; radar illumination pattern; unitary polarization-time waveform matrices; pulse trains

Subjects: Radar equipment, systems and applications; Electromagnetic wave propagation; Codes; Signal processing and detection; Algebra