Multi-channel P-ISAR grating lobes cancellation

The coherent combination of multiple channels for ISAR imaging purposes in passive radar systems is required in order to achieve a good range resolution. Passive ISAR may provides a suitable means to implement automatic target classification (ATC) and automatic target recognition (ATR). The range resolution is related to the transmitted signal bandwidth, therefore adjacent and non adjacent multi-channel signals should be exploited to obtain a wide band signal. This paper addresses the grating lobes issue that rises when a wide band signal with bandwidth gaps is obtained by adjoining multiple adjacent DVB-T channels. A cancellation technique based on the spatially variant apodization (SVA) technique is proposed. Results both on simulated and real data are provided.