MIMO radar three-dimensional imaging via joint time-space observation

A planar-array multiple-input-multiple-output (MIMO) radar system possess the ability to gain a three-dimensional (3-D) image in single snapshot due to the wide-band signal and two-dimensional (2-D) virtual aperture. And the conventional inverse synthetic aperture radar (ISAR) obtains the cross-range resolution thanks to the relative rotational movement during the observation. Naturally, the planar-array MIMO radar 3-D images in multiple snapshots also include slow-time domain Doppler information. In order to take advantage of the Doppler shift along the slow-time domain for a better 3-D imaging result, we investigate the method of MIMO radar 3-D imaging via jointly utilizing the time-space observation. By coherent processing along the velocity direction, inverse aperture caused by target movement is incorporated into the 3-D image focusing and therefore the resolution can be increased. Simulation results validate the effectiveness of the proposed method. Comparing to ISAR, the longtime observation as well as the complicated motion compensation in the proposed 3-D imaging method is not necessary. Besides, comparing to the 3-D image in single snapshot, the proposed method can improve the resolution along the target trajectory efficiently.