Radio imaging of moving targets: the one-dimensional case (microwave range)

The detection of moving targets by passive radio temperature measurements is studied. A radio image is reconstructed by linear spatial filtering of simultaneous measured brightness samples, obtained by multiple regularly spaced antenna beams. With fixed spatial filters, the receiver integration time must be short enough to freeze motion, thus limiting the signal-to-noise ratio obtained in the reconstruction image. It is shown that in the one-dimensional case a time-varying matched spatial filter yields the same signal-to-noise ratio in the reconstructed image as would be obtained from a stationary target with a fixed matched filter