Sector Window SAR Image Edge Detector With Edge Compensation Strategy

It is found that in the edge detection of synthetic aperture radar (SAR) images, conventional Gaussian-Gamma Shaped (GGS) and Ratio of Average (ROA) algorithms use detection windows that tend to cross over the true edges and contain regions of different quality, which leads to high false alarm rates. To solve this problem, the study proposes a new edge detector with a novel window design called the sector window (SW). This scalloped window allows better adaptation to the characteristics of SAR images, faster extraction of thin edges, and reduced inclusion area of different qualitative regions. In addition, in order to extract edges between similar uniform regions more accurately, the study also introduces an edge compensation strategy that enables the algorithm to detect some weak edges that are not easily extracted, thus improving the accuracy in the edge detection process. Both objective and subjective experiments show that the proposed edge detector has important potential for application in synthetic aperture radar image processing by introducing a new sector window and edge compensation strategy that can provide accurate edge detection results.

I. Introduction

Radar remote sensing is one of the current advanced information-gathering technologies, among which synthetic aperture radar (SAR), as an important imaging system for Earth observation, is the subject of much attention and research worldwide. SAR is an active remote sensing imaging sensor system using microwave detection technology. Its imaging principle is to continuously transmit electromagnetic waves to the imaging area through mobile platforms such as satellites and aircraft, and receive radar echo signals while using synthetic aperture technology in the direction of platform movement, and pulse compression of the echo signals in the distance direction and azimuth direction respectively. On this basis, a special imaging algorithm is used to produce high-resolution 2D images. The key technique “synthetic aperture” overcomes the limitations of traditional real aperture techniques in terms of azimuthal resolution and uses temporal sampling due to platform motion instead of fixed real aperture spatial sampling to achieve high resolution in azimuthal direction.