Multi-angle distributed ISAR with stepped-frequency waveforms for surveillance and recognition

The exploitation of data acquired by a multiplatform system has been demonstrated to be able to increase the cross range resolution of ISAR images of rotating targets. In this paper we focus on Distributed-ISAR (D-ISAR) making use of stepped-frequency waveforms, obtaining a high range resolution through a synthetic range-profile processing. Both scenarios, multistatic or MIMO are considered: in the multistatic case one sensor of the formation transmits and the remaining just receive, while in the MIMO case each platform carries an active radar and receives echoes from all the transmissions. A suitable set of waveforms is proposed for the MIMO case and the required focusing technique is shown and tested against simulated D-ISAR data. Moreover, for the multistatic case, the proposed concept and processing scheme are validated by using a set of real data acquired in anechoic chamber.