Sub-aperture phase error stitching for full aperture airborne SAL data processing method based on azimuth deramp

Synthetic Aperture Ladar (SAL) is a combination of synthetic aperture and lidar. At present, sub-aperture stitching with PGA algorithm is used to realize SAL imaging. However, this algorithm has a low rate of data utilization, resulting in a worse image SNR and resolution. For solving this problem, a method of sub-aperture phase error stitching for full aperture airborne SAL data processing based on azimuth deramp is proposed in this paper. The data is divided into a sequence of sub-apertures and the standard Standard Minimum Entropy Autofocus (MEA) is used to estimate the phase error of each sub-aperture. Then all the phase errors of the subapertures are stitched to obtain the full-aperture phase error. After the compensation of the full-aperture phase error, the full-aperture image is obtained by deramp. Compared with the SAL image obtained by sub-aperture algorithm, the method we proposed can offer better resolution and SNR. Finally, the imaging results of airborne SAL real data verify the effectiveness of the proposed algorithm.

Automated summary

The paper proposed a method for processing full-aperture airborne SAL data based on azimuth deramp to improve imaging quality. By estimating the phase error of each sub-aperture and stitching them to obtain the full-aperture phase error, better image resolution and SNR can be achieved.