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The global path planning system is one of the basic systems ensuring the autonomous operation of unmanned underwater vehicles (UUVs) and unmanned surface vehicles (USVs) in a complex aquatic environment. The A* path planning algorithm is one of the most well-known algorithms used to obtain an almost optimal path, avoiding obstacles even in a complex environment containing objects with specific shapes and non-uniform arrangements. The main disadvantage of this algorithm is the computational cost of path calculation. This article presents a new approach based on the image processing of the map before determining the path using A*. The results of numerical research based on a large-sized map expressing the port area confirm the proposed method's effectiveness, which reduces the calculation time by over 500 times with a slight increase in the path length compared to the basic version of the A* algorithm. Based on the obtained results, the proposed approach also increases the path's safety by designating narrow and risky areas as closed to vehicle movement. For this reason, the method seems suitable for use in global path planning for autonomous underwater vehicles (AUVs) and autonomous surface vehicles (ASVs) operating in large areas. [ABSTRACT FROM AUTHOR]

The document titled "Applied Maritime Engineering and Transportation Problems 2022" provides an overview of marine traffic engineering (MTE) and its various research areas. It covers the history of MTE, ship maneuver simulation methods, the design of waterways and ports, and the impact of hydrometeorological conditions on ship behavior. The document also discusses topics such as seafarer competence evaluation, ship-maneuvering simulation in restricted waters, and port infrastructure optimization. It emphasizes the interdisciplinary nature of MTE and its importance in ensuring safe, efficient, and sustainable maritime operations. The future of MTE includes advancements in automation, artificial intelligence, cybersecurity, environmentally friendly technologies, and global cooperation for shipping safety. [Extracted from the article]

Performing any measurement on watercraft is connected with many additional difficulties caused by the sea-environment. The most important is the problem of spatial stabilization of measurement systems, which are usually fastened to craft body. As soon as usually these measurement are executed during the move of the craft additional question is the accuracy of execution the planed trajectory.

This paper presents a dynamic hyperboloidal mapping model aimed at building image of electronic navigational chart which constitutes an equivalent to that obtained from a hypercatadioptric camera system. In the 1st part, space and three reference frames located in it are defined. These are: the observer frame and horizontal topocentric frame considered secondary (both connected with water-surface platform), and the geocentric frame, primary one. The 2nd part provides description of a way of interconnection between the observer frame and horizontal topocentric one as well as of determination of their location in relation to the geocentric reference frame, depending on course and position of water-surface platform. In the final part is presented a model of panoramic image mapping in the observer reference frame and principles of generating ENC image by using dynamic hyperboloidal mapping. Finally, conclusions indicating possible applications of the developed model are presented.

W artykule przedstawiono optyczną metodę wyznaczania pozycji obiektów nawodnych z lądu. Oparto ją na dwóch punktach odniesienia o znanych współrzędnych geograficznych. Pierwszy umiejscowiono wysoko na brzegu morza i przeznaczono do zamontowania kamery. Drugi przeznaczono do określania płaszczyzny horyzontu topocentrycznego i umiejscowiono na poziomie lustra wody.

The article presents a study of the accuracy of estimating the position coordinates of BAUV (Biomimetic Autonomous Underwater Vehicle) by the extended Kalman filter (EKF) method. The fusion of movement parameters measurements and position coordinates fixes was applied. The movement parameters measurements are carried out by on-board navigation devices, while the position coordinates fixes are done by the USBL (Ultra Short Base Line) system. The problem of underwater positioning and the conceptual design of the BAUV navigation system constructed at the Naval Academy (Polish Naval Academy—PNA) are presented in the first part of the paper. The second part consists of description of the evaluation results of positioning accuracy, the genesis of the problem of selecting method for underwater positioning, and the mathematical description of the method of estimating the position coordinates using the EKF method by the fusion of measurements with on-board navigation and measurements obtained with the USBL system. The main part contains a description of experimental research. It consists of a simulation program of navigational parameter measurements carried out during the BAUV passage along the test section. Next, the article covers the determination of position coordinates on the basis of simulated parameters, using EKF and DR methods and the USBL system, which are then subjected to a comparative analysis of accuracy. The final part contains systemic conclusions justifying the desirability of applying the proposed fusion method of navigation parameters for the BAUV positioning.

The paper provides a description of a method of drafting route plan templates on the basis of AIS (automatic identification system) historical data. The first section features a brief background on the problem of drafting route plan templates in the light of international regulations. The main section contains a description of the methods and tools used for processing AIS data into a GRID reference system: ship traffic intensity, average COG (course over ground) and average SOG (speed over ground) as well as route plan templates. The final section includes a presentation of the research method and an analysis of the results, conducted on the basis of maps with charted paths of drafted route plan templates. The summary constitutes a synthesis of general conclusions, the advantages and disadvantages of the solution as well as areas for further research to enhance the solution. [ABSTRACT FROM AUTHOR]

The geometric distribution of navigational aids is one of the most important elements to be taken into account in the planning of maritime terrestrial navigation systems. It determines to a large extent the capability of vessels to obtain high-precision position coordinates. Therefore, the optimisation of their location is a key element at the planning stage, in particular on port approach fairways. This article attempts to use computer simulation methods to assess the positioning accuracy of a vessel that follows a constant course and speed on a port approach fairway. The analysis uses a technique based on the Extended Kalman Filter (EKF) Two-Dimensional (2D) Range-Bearing Simultaneous Location and Mapping (SLAM) method. In the simulation experiment conducted, the research object determined its position based on bearing and distance to fixed position beacons, which changed their locations in subsequent passages of the vessel. A geometrically optimal configuration of the terrestrial navigation marking system guaranteeing the highest positioning accuracy was identified as a result of the deliberations. The study analysed more than 20,000 cases of different configurations (locations) of the fixed position beacons, demonstrating that the adopted algorithm can be used successfully in the planning of their deployment in the context of ensuring minimum accuracy requirements for the positioning of navigational signs on port approach fairways and under restricted conditions by navigational marking services, as set out in International Maritime Organization (IMO) Resolutions A915 (21) and A953(22). [ABSTRACT FROM AUTHOR]

This paper summarises research that evaluates the precision of determining a ship's position by comparing an omnidirectional map to a visual image of the coastline. The first part of the paper describes the equipment and associated software employed in obtaining such estimates. The system uses a spherical catadioptric camera to collect positional data that is analysed by comparing it to spherical images from a digital navigational chart. Methods of collecting positional data from a ship are described, and the algorithms used to determine the statistical precision of such position estimates are explained. The second section analyses the results of research to determine the precision of position estimates based on this system. It focuses on average error values and distance fluctuations of position estimates from referential positions, and describes the primary factors influencing the correlation between spherical map images and coastline visual images. [ABSTRACT FROM AUTHOR]

This article describes studies that evaluate the accuracy of measuring a ship's heeling angle with an inclinometer. It does so by comparing inclinometer readings with benchmark measurements made with the optical method. The first part of the article describes the measurement station used for gathering measurement data. This station included an inclinometer and a CCD camera, and was used to process digital images incorporating a horizon line to indicate the ship's heeling angle. The second part of the article describes the data gathering process carried out on a ship at sea. The final part describes a statistical analysis which compares the angular measurements based on an inclinometer with simultaneous optical benchmark measurements. [ABSTRACT FROM AUTHOR]

This article presents the concept of algorithm A* functioning in a navigation system equipped with electronic navigational chart for autonomous planning the shortest and safest route crossing an offshore unmanned vehicle "Edredon". The first part describes the general technical architecture and functionality of the vehicle's navigation system. In the second part shows in detail the modules of the system responsible for the planning of the road and how to implement them in the A* algorithm. The third part describes the proper operation of testing whether the A* algorithm in the navigation system, while the task of planning the route of the autonomous vehicle. Final part is a discussion of the results obtained from tests carried out in order to evaluate the applicability of the A* algorithm for route planning in autonomous navigation systems. [ABSTRACT FROM AUTHOR]

Evaluation of accuracy of position coordinates' determination in respect to floating marks, with free adjustment method applied, has been a target of the paper. General theory of geodesic adjustment - classical one based on least squares method and free adjustment - is presented in its first part. Main part contains description of the research. It was conducted based on geometric navigational structure which elements had been formed by beacons placed in the Bay of Gdańsk. It consisted in simulating results of measurements made in respect to marks of this structure (bearings and distances) and calculating the position coordinates based on them, as well as its accuracy. The calculations were made with the method of classical geodesic adjustment and free adjustment applied. Discussion about obtained results of the research and general conclusions are given in the ending part of the article. [ABSTRACT FROM AUTHOR]

A market for small drones is developing very fast. They are used for leisure activities and exploited in commercial applications. However, there is a growing concern for accidental or even criminal misuses of these platforms. Dangerous incidents with drones are appearing more often, and have caused many institutions to start thinking about anti-drone solutions. There are many cases when building stationary systems seems to be aimless since the high cost does not correspond with, for example, threat frequency. In such cases, mobile drone countermeasure systems seem to perfectly meet demands. In modern mobile solutions, frequency modulated continuous wave (FMCW) radars are frequently used as detectors. Proper cooperation of many radars demands their measurements to be brought to a common coordinate system—azimuths must be measured in the same direction (preferably the north). It requires calibration, understood as determining constant corrections to measured angles. The article presents the author's method of fast, simultaneous calibration of many mobile FMCW radars operating in a network. It was validated using 95,000 numerical tests. The results show that the proposed method significantly improves the north orientation of the radars throughout the whole range of the initial errors. Therefore, it can be successfully used in practical applications. [ABSTRACT FROM AUTHOR]

The paper presents the results of research on assessing the accuracy of angular position measurement relative to the sea horizon using a camera mounted on an unmanned bathymetric surveying vehicle of the Unmanned Surface Vehicle (USV) or Unmanned Aerial Vehicle (UAV) type. The first part of the article presents the essence of the problem. The rules of taking the angular position of the vehicle into account in bathymetric surveys and the general concept of the two-camera tilt compensator were described. The second part presents a mathematical description of the meters characterizing a resolution and a mean error of measurements, made on the base of the horizon line image, recorded with an optical system with a Complementary Metal-Oxide Semiconductor (CMOS) matrix. The phenomenon of the horizon line curvature in the image projected onto the matrix that appears with the increase of the camera height has been characterized. The third part contains an example of a detailed analysis of selected cameras mounted on UAVs manufactured by DJI, carried out using the proposed meters. The obtained results including measurement resolutions of a single-pixel and mean errors of the horizon line slope measurement were presented in the form of many tables and charts with extensive comments. The final part presents the general conclusions from the performed research and a proposal of directions for their further development. [ABSTRACT FROM AUTHOR]