3D imaging for tracking and aim-point maintenance in the presence of target-pose changes

We propose a three-dimensional imaging approach based on digital holography. Our approach is based on frequency diversity using a single chirped pulse instead of a train of pulses with different frequencies. Our approach promises to mitigate most of the issues limiting the performance of current methods and offer additional enabling capabilities that will improve target identification and tracking. Instead of a train of pulses with increasing discrete frequencies, we use a single pulse with a continuous frequency chirp of several GHz. Our approach achieves the frequency diversity in a continuous fashion instead of a discrete fashion, which will eliminate aliasing effects. Furthermore, because of the continuous chirp (per pulse), the imaging rate is limited by the speed of the sensing array. Compressing the pulse train into a single equivalent but shorter pulse also minimizes non-simultaneous imaging distortion effects. The broad frequency chirp also helps in mitigating Stimulated Brillouin Scattering (SBS), which facilitates power scaling of the system to achieve longer ranges.