A New Synthetic Aperture Radar (SAR) Imaging Method Combining Match Filter Imaging and Image Edge Enhancement

Abstract

In general, synthetic aperture radar (SAR) imaging and image processing are two sequential steps in SAR image processing. Due to the large size of SAR images, most image processing algorithms require image segmentation before processing. However, the existence of speckle noise in SAR images, as well as poor contrast and the uneven distribution of gray values in the same target, make SAR images difficult to segment. In order to facilitate the subsequent processing of SAR images, this paper proposes a new method that combines the back-projection algorithm (BPA) and a first-order gradient operator to enhance the edges of SAR images to overcome image segmentation problems. For complex-valued signals, the gradient operator was applied directly to the imaging process. The experimental results of simulated images and real images validate our proposed method. For the simulated scene, the supervised image segmentation evaluation indexes of our method have more than 1.18%, 11.2% and 11.72% improvement on probabilistic Rand index (PRI), variability index (VI), and global consistency error (GCE). The proposed imaging method will make SAR image segmentation and related applications easier.

Residual Motion Error Correction with Backprojection Multisquint Algorithm for Airborne Synthetic Aperture Radar Interferometry

“…Generally, airborne SAR transmits a wideband pulse chirp (linear frequency modulation) signal, and achieves range focusing. For simplicity, taking the echo signal of the scattering point P as an example, the signal after the pulse compression can be given by [21], which is shown as follows sic=Ciprefixexp{}−j2πfcτi where i is the slow-time pulse index, Ci is the amplitude after pulse compression, fc is the radar center frequency, and τi is the two-way propagation time from the radar antenna to P . The realization process of BP can be written by [2] I=∑i=−NNsicprefixexp{}j2πfcτi˜=∑i=−NNCiprefixexp{}−j2πfcτi−trueτi˜ where I is defined as the final focus of the scattering point, N is the pulse index range of the synthetic aperture, and τi˜ is the delay of the projection point Q of the tar...…”

Windowing Accuracy Evaluation for PSLR Enhancement of SAR Image Recovery

“…This enables its sensor to provide high resolution imagery which will not be degraded with distance as in the case of traditional radar systems with large antennas. For these reasons, SAR becomes a more popular imaging sensor in most practical applications [1][2][3][4][5]. There are different modes of operation of SAR systems.…”