3D TARGET DETECTION USING STACKED HOLOGRAM

Abstract

A very popular technique of 3D vision now-a-days is holography which has many advantages over the stereoscopic 3D vision. The same technique can be implemented on RADAR to take high resolution 3D picture of the target and to track with very minute displacement. As this does not employ parallax method, so binocular antenna can be replaced by a single antenna. Again in this thesis another new concept, gated range, is implemented, i.e., the target can be detected within a certain range on spatial domain so that it can focus to the target and the clutter has no effect on it. Narrow virtual transmit pulses are synthesized by differencing long-duration, staggered pulse repetition interval (PRI) transmit pulses. PRI is staggered at an intermediate frequency IF. Echoes from virtual pulses form IF-modulated interference patterns with a reference wave. Samples of interference patterns are IF-filtered to produce high spatial resolution holographic data. PRI stagger can be very small, e.g., 1-ns, to produce a 1-ns virtual pulse from very long, staggered transmit pulses. Occupied Bandwidth (OBW) can be less than 10 MHz due to long RF pulses needed for holography, while spatial resolution can be very high, corresponding to ul tra-wideband (UWB) operation, due to short virtual pulses. X-Y antenna scanning can produce range-gated surface holograms from quadrature data. Multiple range gates can produce stacked-in-range holograms. Motion and vibration can be detected by changes in interference patterns within a range-gated zone.