A Synergic Integration of AIS Data and SAR Imagery to Monitor Fisheries and Detect Suspicious Activities

Abstract

Maritime traffic and fishing activities have accelerated considerably over the last decade, with a consequent impact on the environment and marine resources. Meanwhile, a growing number of ship-reporting technologies and remote-sensing systems are generating an overwhelming amount of spatio-temporal and geographically distributed data related to large-scale vessels and their movements. Individual technologies have distinct limitations but, when combined, can provide a better view of what is happening at sea, lead to effectively monitor fishing activities, and help tackle the investigations of suspicious behaviors in close proximity of managed areas. The paper integrates non-cooperative Synthetic Aperture Radar (SAR) Sentinel-1 images and cooperative Automatic Identification System (AIS) data, by proposing two types of associations: (i) point-to-point and (ii) point-to-line. They allow the fusion of ship positions and highlight “suspicious” AIS data gaps in close proximity of managed areas that can be further investigated only once the vessel—and the gear it adopts—is known. This is addressed by a machine-learning approach based on the Fast Fourier Transform that classifies single sea trips. The approach is tested on a case study in the central Adriatic Sea, automatically reporting AIS-SAR associations and seeking ships that are not broadcasting their positions (intentionally or not). Results allow the discrimination of collaborative and non-collaborative ships, playing a key role in detecting potential suspect behaviors especially in close proximity of managed areas.

MMFlood: A Multimodal Dataset for Flood Delineation From Satellite Imagery

“…However, several 269 works have been carried out on remote sensing SAR data, 270 from image despeckling [47], [48], to the detection of large 271 objects such as ships [25], [49] and land cover classifica-272 tion [8], [24]. SAR imagery is often enriched with informa-273 tion derived from additional sources, including optical data 274 such as Sentinel-2 [24], or even completely different modal-275 ities such as Automatic Identification Systems (AIS), which 276 is often exploited in vessel detection as both supplementary 277 knowledge through domain adaptation [50] or ad-hoc data 278 fusion [51].…”

Application of Optimized Grey-Markov Model to Land Subsidence Monitoring With InSAR

“…The basic principle is to perform sequential InSAR processing of several acquired SAR images analyze the phase and amplitude specific information of the obtained points, identify some relatively stable target points, such as buildings, rocks, road lands, and even previously installed artificial angle reflectors. Since these point targets are relatively stable, the high echo signal intensity can maintain its relatively stable ground reflection properties for a considerable time [12]. IPTA timing analysis technology calculates the value change in elevation information and the positive value of the deformation rate.…”

“…By contrast, the use of InSAR technology to monitor the land deformation of the mining area obtains a range of high-precision monitoring data; and effectively reduces manpower and material resources, reducing the great cost and investment, and completing the continuous real-time monitoring of the whole mining area [6], [9]. With the continuous break-through and improved timing of InSAR technology in recent years, highly accurate deformation information can be obtained theoretically, and the accuracy of its data processing results can reach the centimeter-level [10] - [12]. Therefore, we can research and work on land subsidence prediction through InSAR technology.…”

Multi-Criteria Selection of Surface Units for SAR Operations at Sea Supported by AIS Data

“…Wang et al [12] describe an innovative approach to missing data filling through multiple imputation. The possibilities of using SAR and AIS to search for and detect vessels are presented in [13,14]. Ship detection using SAR and AIS was discussed in [15].…”

“…Ship detection using SAR and AIS was discussed in [15]. A novel approach to how to integrate AIS and Synergic Aperture Radar signals and data for vessel traffic and monitoring is presented in [14,16].…”