Synthetic-aperture radar based on nonsinusoidal functions. I - Moving radar and stationary arrays in one or two dimensions

Synthetic-aperture radar in the form known for more than twenty years uses the Doppler shift of a periodic sinusoidal wave caused by the relative motion between a radar and a target. This paper investigates the use of pulses to produce a synthetic-aperture radar. It is assumed that the pulses are either too short to show a useful Doppler shift or that one wants to use the Doppler shift for something else than to generate a synthetic aperture. The pulses may or may not be radiated with the help of a sinusoidal carrier. It is shown that the equivalent of the usual sidelooking radar mounted on a moving vehicle exists for the pulse technique. In addition, one can implement a stationary synthetic-aperture radar with either a one- or a two-dimensional sensor array. Numerical values for the typical resolution are not given in this paper, since they depend on a more-detailed definition of the pulses to be used. This matter will be discussed in a future paper. Also postponed to future papers are the use of the Doppler shift for beamforming with nonsinusoidal waves, and the practical use of synthetic-aperture techniques for all-weather tracking radars, beam riders, etc.