Abstract:In order to select a suitable time interval to reconstruct a well-focused ISAR image for maneuvering target in long recorded data, a novel method based on Phase Linear Degree (PLD) is proposed in this paper. Firstly, the scatterer phase property is deduced in detail and the imaging time condition is given. Secondly, two prominent range cells are selected based on the Average Range Profile (ARP), and the radial phase is removed by the two range cells conjugate multiplication. Then the rotation phase is curve fitting based on the unwrapping phase. Accordingly, the phase linear degree of the rotation phase is evaluated at the different time interval, and the interval with the highest phase linear degree is selected as the imaging time. Finally, the technique effectiveness is tested by simulated and real data.