Ship Navigation Status Estimation via SAR Wake Pattern Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ship behavior analyzing methods face challenges in accurately determining the navigation status of ships, especially when AIS signals are manually stopped or the radar's range is limited, making it difficult to monitor entire sea areas and detect non-targeted suspicious behavior.
Innovation Solution
A ship behavior analyzing device that uses synthetic aperture radar (SAR) data to detect ships, extract wakes, generate wake pattern images, and estimate navigation status, enabling stable navigation status estimation even when AIS signals are stopped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If AIS signals are used to detect ship behavior, then navigation status can be obtained, but AIS signals can be manually stopped by seafarers making detection unreliable
Solution Approach 1:
The patent introduces SAR (Synthetic Aperture Radar) as an intermediary detection method to replace AIS when AIS signals are unavailable or unreliable. SAR detects ship wakes directly from radar images, providing an alternative information channel that does not depend on cooperative AIS transmission, thus resolving the reliability issue when AIS is manually stopped.
Solution Approach 2:
Instead of relying on active signals transmitted by ships (AIS), the patent inverts the approach by detecting passive physical phenomena (ship wakes) that naturally occur during ship operation. This inversion allows detection without requiring ship cooperation, eliminating the vulnerability to manual signal cessation.
2Area of stationary object
If ship-mounted radar is used to detect suspicious ships, then ships around own ship can be detected, but the detection range is limited to several tens of km
Solution Approach 1:
The patent uses SAR technology to create detailed wake pattern images from satellite or aerial radar observations. These wake pattern copies can be analyzed to determine navigation status and detect suspicious behavior over large sea areas, effectively extending the detection capability beyond the limited range of ship-mounted radars while maintaining detailed analysis capability.
3Adaptability or versatility
If ship-mounted radar is used for suspicious ship detection, then ships targeting own ship can be detected, but non-targeted suspicious behavior cannot be detected
Solution Approach 1:
The patent implements a universal wake detection system that can identify multiple types of suspicious behavior through a single SAR-based wake analysis mechanism. The system detects not only ships targeting own ship but also other suspicious activities such as unusual navigation patterns, abnormal wake characteristics, and atypical movement behaviors, thereby achieving multi-functional detection capability.
Data Source
AI summary
An object of an example embodiment of the present disclosure is to stably estimate a navigation status of a target ship at a predetermined time from time-series position information of the ship. A ship behavior analyzing device according to the example embodiment of the present disclosure includes a ship detection means for detecting a ship from synthetic aperture radar (SAR) data, a wake extraction means for extracting a wake of the detected ship, a wake pattern generation means for generating a wake pattern image by using the extracted wake, and a navigation status estimation means for estimating a navigation status of the target ship by using the generated wake pattern image.