Detection of ground moving targets via MIMO SAR systems

Multichannel space-based SAR systems that exploit receiving antenna sub-arrays displaced in the along track-direction have been shown to provide the capability to detect ground moving targets and potentially estimate their radial motion velocity, thus making possible their correct relocation inside the SAR image of the background. However, the use of only two receiving channels to contain cost, mass and data-rate, imposes limitations in terms of potentiality of joint clutter cancellation and target velocity estimation. To overcome this problem we propose a full MIMO SAR scheme obtained by transmitting nearly orthogonal waveforms with the two sub-arrays achieved from a single antenna aperture, and receiving with the two sub-arrays. A complete processing chain for the joint detection, imaging and radial speed estimation is presented and the performance of the proposed MIMO system is deeply investigated and compared to the performance of conventional multichannel systems to assess the relative merits and drawbacks.