Cross-range scaling for ISAR via optical flow analysis

For high resolution imaging applications, ISAR can be viewed as a kind of camera which linearly maps the scattering centers from the physical plane to the RD image plane. Thus, the concept and methods of optical flow in computer vision may be introduced for the rotation estimation in ISAR. Furthermore, three kinds of optical flow analysis-based estimators, namely triangle-based, line-based, and image rotation correlation-based estimators, are provided to estimate the coo on the RD image series herein. Because the RD image series is a common output of conventional ISAR and only the scattering center operators are used, the proposed optical flow-based method may also be computationally efficient. Besides, with the increase of scattering centers and images, the high accuracy of cross-range scaling can also be guaranteed. Finally, experimental results are provided to demonstrate the effectiveness of proposed methods based on some measured data of Yak airplane.