Radar Tomographic Imaging – Achieving High Resolution With Spatial Diversity

It is well known that the range resolution of conventional radar is typically limited by the bandwidth of adopted radar waveform, and the cross-range resolution is limited by the radar beamwidth. Synthetic aperture radar (SAR) exploits the radar motion to form a long virtual antenna aperture, which can significantly improve the cross-range resolution and make it comparable or equal to the range resolution. However, we should not forget that the potential spatial resolution that radar can achieve could be much better, more precisely, in the order of sub-wavelength. Such radar operating mode is called radar tomography or radar tomographic imaging, which exploits large spatial diversity, instead of large waveform bandwidth, to achieve high spatial resolution. In this talk, the principle of radar tomographic imaging is introduced and the measurement results in microwave anechoic chamber are presented to demonstrate its superior high spatial resolution. Some examples of radar tomography technique in real-world applications are also addressed.