Translational Motion Estimation and Compensation in Inverse Synthetic Aperture Radar

For Inverse Synthetic Aperture Radar (ISAR) imaging of a ship, the only desired motion is the rotational motion of the target towards the Radar. The translational motion between the Radar and target can severely distort the image especially for Airborne Radar imaging a non-cooperative naval target. This paper presents a robust and computationally efficient algorithm for estimating the translational motion between the Radar and target from the collected data itself and compensating for it. The algorithm is based on batch profile correlation and phase compensation in the raw data. It is robust to background noise and target scintillation effects and removes the problem of error accumulation inherent in peak-tracking method. The algorithm is applied to simulated ISAR data as well as actual ISAR data collected by X-band airborne radar. The results are presented in the paper for various scenarios.