Passive 3D interferometric ISAR using target-borne illuminator of opportunity

This study proposes a new idea for forming three-dimensional (3D) passive inverse synthetic aperture radar (ISAR) images. Two main innovations are presented, the first that is related to the use of a dual interferometer and the second that considers the illuminator of opportunity (IO) located on the target to be imaged. A theoretical approach was proposed in a previous study that demonstrated passive ISAR imaging with a target-borne IO in the 2D domain. In the present study, such approach is extended to a full 3D case. A complete theoretical derivation is proposed for the formation of point-like 3D ISAR images when using target-borne IOs. Simulations are used to produce some examples. Practical issues and limitations are also discussed.