In the field of maritime safety research, ship behavior analysis is usually based on data provided by automatic identification systems (AISs). Prevailing studies predominantly focus on detecting the behaviors of vessels that may affect maritime safety, especially the abnormal disappearance of ship AIS signals, neglecting subsequent measures to trace these illegal ships. To fill this gap, we propose a deep learning model named multi-dimensional convolutional long short-term memory (MConLSTM) to tackle the challenge of recognizing ship trajectories in cases where AIS signals are intentionally altered. By employing a self-supervised approach, the model is trained using historical real-world data. Extensive experiments show that MConLSTM exhibits superior analytical capabilities when it comes to processing and analyzing AIS data. Notably, even in scenarios with scant training data, the model exhibits exceptional performance, with an average accuracy 22.74% higher than the general model. Finally, we validated the practical significance and feasibility of the proposed method by simulating real-world scenarios.

An aerial Radio Environment Map (REM) characterizes the spatial distribution of Received Signal Strength (RSS) across a geographic space of interest, which is crucial for optimizing wireless communication in the air. Aerial REM construction can rely on Unmanned Aerial Vehicles (UAVs) to autonomously select interesting positions for sampling RSS data, enhancing the quality of construction. However, due to the lack of prior information about the environment, it is challenging for UAVs to determine suitable sampling positions online. Additionally, achieving efficient exploration of the target area through collaboration among multiple UAVs is difficult. To address this issue, this paper proposes a multi-stage approach to data sampling and path planning with multiple UAVs. Specifically, the UAVs’ data sampling task over the target area is divided into multiple stages. By selecting an appropriate stage position, we use the RSS values at that position to determine whether additional data need to be sampled in a specific local area. At each stage, the area is divided into Voronoi diagrams based on the current position of each UAV, assigning each UAV its own region to explore. In our sampling strategy, the probability distribution for sampling is obtained by estimating the RSS and uncertainty of unsampled positions and then taking the weighted sum of these two values. To obtain the shortest flight path for selected sampling positions, we employ a network structure based on self-attention as the policy network, which is trained through the actor–critic framework to obtain an improvement heuristic strategy, replacing traditional manually designed strategies. Experimental results across three different scenarios indicate that the approach improves the quality of aerial REM construction while efficiently planning the shortest paths for UAVs between sampling positions.