Research On The Technique Of Inverse Synthetic Aperture Radar Imaging And Scaling

Inverse synthetic aperture radar (ISAR) is a kind of important high-resolution radar. It has the capability of getting high resolution images of non-cooperative targets at long distance under all-weather and all-day, so it is with great military and civil values. To meet the target recognition demand in practical application, some technique about ISAR imaging and ISAR image process, including ISAR imaging of ship targets, optimum imaging instant selection, cross-range scaling and so on, are discussed in this dissertation.Chapter 1 is the introduction. The history of ISAR imaging development is reviewed and the dissertation's research background and main work are introduced.The basic concepts of ISAR imaging and the principle of Range-Doppler (short for RD) imaging algorithm are studied in Chapter 2. Then, the principle of the airborne ISAR imaging of ship targets is elaborated. Lastly, the effect of ship 3-D motion (roll, pitch and yaw) on ISAR imaging is exposited in detail, and some relevant simulation results are presented.Considering the complex motion of the ship targets, it is difficult to get the clear images of the targets by the simple RD algorithm. In Chapter 3, a method to select the optimal ship imaging time based on the estimation of effective rotation vectors is proposed. Then it's easy to select proper times for top-view and side-view of ship, which benefit for the next target recognition.Cross-range scaling of the ISAR image is a technique difficulty. In Chapter 4, a new scaling method completely based on the obtained target image is proposed. It can achieve scaling for the plane ISAR image and the ship top-view ISAR image, without the information of target tracking and the scatters'position of the target.