TABLE OF CONTENTS Sensor systems such as radar or sonar receivers are tools for the interpretation of waves. A wave is by definition a function of space and time. Therefore, wave processing techniques basically include the spatial or temporal dimension or both. Synthesis of an antenna directivity pattern can be interpreted as spatial processing. Operations such as demodulation, filtering or Fourier analysis of the antenna output signal are temporal processing techniques.
Space-time signal processing is required whenever there is a functional dependency between the spatial and temporal variable. This is fulfilled in several applications, for example:
moving pulse Doppler radar: dependency of the clutter Doppler frequency on the direction of arrival;
frequency dependency of the directional response of an antenna array with narrowband beamforming;
ambient noise in sonar (different frequencies arriving from different directions).
Space-time processing techniques can typically be applied in areas such as
airborne MTI radar (BRENNAN et al. [54]);
synthetic aperture radar (SAR), see ENDER [108], BARBAROSSA and FARINA [31], DONG et al. [98];
spaceborne MTI radar (SEDWICK et al. [456], MAHER and LYNCH [330]);
clutter cancellation for SAR/ISAR (ENDER [108], MERIGEAULT et al. [354], GENELLO et al. [146]);
interference suppression in narrowband radar through artificial array motion (LEWIS and EVINS [304]);
interference suppression for broadband radar (COMPTON [80, 79]);
wideband interference rejection in GPS receive arrays (FANTE and VACCARO [121]);
terrain scattered jamming (GABEL et al. [139], KOGON et al. [282, 283], ABRAMOVICH et al. [1,...
