An Improved Method of Land Masking for Synthetic Aperture Radar-based Ship Detection

Abstract

Land masking of Synthetic Aperture Radar (SAR) images is generally accomplished by applying either archived shoreline databases or image segmentation. However, those methods cannot be solely applied to geographical areas complicated with many small islands and exposed rocks. Therefore, we have proposed a new procedure where Sobel edge extraction is applied to detect the edges of all objects from KOMPSAT-5 X-band SAR images, followed by a merging process with the edges from the land objects based on Electronic Navigational Chart (ENC) coastlines. Using the land mask data, geometrically corrected SAR images were masked before applying a ship detection algorithm. This land masking procedure was applied to several images covering different areas of the Korean Peninsula. The results show that land targets such as newly constructed and natural objects were also masked, and thus did not create false alarms during ship detection. Therefore, this method can be used to assist precise ship detection using SAR images in coastal waters.

Detection of maritime traffic anomalies using Satellite-AIS and multisensory satellite imageries: Application to the 2021 Suez Canal obstruction

“…The workflow for detecting the ships from the satellite images is shown in Figure 3. At first, the Sentinel-1 data were radiometrically and geometrically corrected followed by land masking, applying a 3 × 3 size sliding window, data binarisation and finally removal of false detection from the noise by image erosion and dilation (Yang et al, 2018; Bae and Yang, 2020).…”

Lightweight deep network-enabled real-time low-visibility enhancement for promoting vessel detection in maritime video surveillance

“…Both the traditional remote sensing-based technology, for example, synthetic aperture radar (Yang et al, 2018;Chaturvedi, 2019;Liu et al, 2021), and the automatic identification system (AIS) (Zhang et al, 2016(Zhang et al, , 2017 have been salient achievements in maritime surveillance. However, these methods require special equipment to be installed on both vessels and observation stations.…”

“…In the current literature, many vision-based technologies of vessel detection and tracking have been developed (Zhang et al, 2017;Yang et al, 2018;Liu et al, 2021aLiu et al, , 2021b for effective maritime surveillance. These methods have been verified to generate satisfactory vessel detection results in normal lighting environments.…”

Waterline Extraction for Artificial Coast With Vision Transformers

“…The edge-based methods utilize the distinctive edge feature from the abrupt transition. The common methods including Sobel, Roberts (Yang et al, 2018), Laplacian, and Canny operators (Lin et al, 2013;Paravolidakis et al, 2016;Ao et al, 2017;Widyantara et al, 2017;Paravolidakis et al, 2018) can be adopted to extract the waterline. Wang and Liu (2019) proposed a robust ridge-tracing method utilizing the statistical properties of the pixel intensities in the land and sea to detect the boundary.…”