Krzysztof Czaplewski

M-Estimation as a Tool Supporting a Vessel Traffic Controller in the VTS System

Abstract In order to improve maritime safety and the efficiency of vessel traffic, systems supervising vessel traffic, i.e. VTS (Vessel Traffic Service), started to be created. These systems are aimed to control vessel traffic in waters where traffic congestion, a large concentration of vessels or the presence of navigational hazards creates a risk of collision or stranding. VTS systems constitute maritime safety centres and they must be equipped with appropriate devices in order to be fully functional. Among devices that provide information about vessels are coastal radar stations which are located around a monitored sea area. This kind of spatial arrangement of these stations can be used to simultaneously obtain information about every vessel, but such observations may be fraught with serious errors. Therefore, the estimation methods that are employed and developed in geodesy can be used to improve the accuracy with which a vessel’s position is determined. The Interactive Navigational Structure, i.e. IANS, is an example of how these methods can be applied in navigation; this term has already been introduced into the literature (Czaplewski, 2004). The text below presents the theoretical assumptions underlying the use of IANS as a tool supporting a vessel traffic controller using the VTS system in his/her work. This presentation is supported by a numerical test that was performed in the waters of the Bay of Gdańsk which are covered by the VTS system.

The application of methods of robust M-estimation in establishing ship position in marine traffic surveillance systems based on radar observations

ABSTRACT In the last years considerable emphasis has been placed on safety at sea. There is the maritime security and surveillance system whose main aim is to execute tasks in the interests of maritime safety and to react in case of emergency. They are monitored by networks of radar stations. On such areas we obtain a lot of navigation data which could be used to improve ship’s parameters (position), using know in geodesy modern M-estimation methods. Simultaneous acquisition of navigational information from many independent radar stations will render it possible to obtain a more accurate ship position in marine traffic surveillance systems in relation to the calculated position. A position expected in an adjustment calculus is received from a watch officer. It is burdened with a fallacy of navigation systems and the quality of marking ship’s route on a map. In the case of navigational-parameter measurements used for depicting ship position, one can obtain incorrect results due to a disturbance in the measurement process. In extreme cases, such erroneous data could significantly differ from the anticipated results. Deviating observations could significantly influence the values of measurement results. In order to eliminate the determination of erroneous measurements, one could use resistant estimation methods with suitably selected attenuation functions. The accuracy of a determined position will not be better than the capabilities of the device used. Adjustment gives the possibility of eliminating or minimizing human errors as well as the errors in the indications of navigational devices. This paper presents the latest robust estimation methods using Danish attenuation function for adjustment of navigational observation, using radar observation. STRESZCZENIE W ostatnich latach znaczny nacisk kładzie się na bezpieczeństwo na morzu. Jest to zasadniczy cel tworzenia morskich systemów nadzoru i bezpieczeństwa, które powinny zareagować w razie pojawienia się zagrożenia. Ten nadzór jest realizowany poprzez sieć stacji radiolokacyjnych. Na takich obszarach otrzymujemy dużo danych nawigacyjnych, które mogłyby zostać użyte dla poprawienia parametrów statku (pozycji) przy użyciu nowoczesnych metod M-estymacji znanych z geodezji. Równoczesne pozyskiwanie informacji nawigacyjnej z wielu niezależnych stacji radiolokacyjnych stwarza możliwości otrzymania dokładniejszej pozycji statku niż odbierana dotychczas w morskich systemach nadzoru ruchu morskiego. Pozycja estymowana w rachunku wyrównawczym jest otrzymywana od oficera wachtowego. Jest ona obarczona błędami systemów nawigacyjnych i jakości zaznaczenia trasy statku na mapie. W wypadku pomiaru parametrów nawigacyjnych używanych dla przedstawiania pozycji statku można otrzymać niepoprawne wyniki z powodu zakłóceń procesu pomiarowego, a błędne obserwacje mogą znacząco wpłynąć na wyniki. Dla wyeliminowania złych pomiarów można by użyć odpornych metod estymacji z odpowiednio dobraną funkcją wzmocnienia. Dokładność wyznaczonej pozycji nie będzie większa niż możliwości użytych systemów pomiarowych. Estymacja daje możliwość eliminowania albo minimalizacji błędów ludzkich oraz błędów we wskazaniach urządzeń nawigacyjnych. Artykuł przedstawia najnowszą metodę estymacji z wykorzystaniem tzw. duńskiej funkcji wzmocnienia dla dostosowania obserwacji nawigacyjnych opartych na obserwacjach radarowych.

Protection of Visual Data Transmission for Vessel Traffic Systems Using Joint Fingerprinting and Decryption Method Based on Modified Hill Cipher

Abstract Vessel traffic systems provide a high level of safety on coastal waters due to coastal radar stations and industrial cameras transmitting information to traffic supervision centers, as well. To improve a vessel traffic services is very important to ensure the speed and secrecy for the transmission of video images. The paper presents the basic issues of the multimedia data protection by digital watermarking and fingerprinting methods. Main applications for such digital marking were described in the paper as well as its requirements. Furthermore, the importance of multicast transmission for fingerprinting methods was presented by comparing the scalability of methods using only unicast transmissions and methods using multicast transmissions. The paper also presents the greatest threat to fingerprinting methods, which are attacks performed by more than one pirate. These attacks are called collusion attacks. The criteria that should be followed during identifying rogue users taking part in the collusion attack on the security systems has been presented. The paper also contains description of the extended Hillcast method, which belongs to the group of JFD (Joint Fingerprinting and Decryption) methods. The method provides a cryptographic security and digital fingerprinting of multimedia content, while maintaining high scalability. Main purpose of this method is VoD (Video on Demand) service, but it can also be used in vessel traffic supervision systems, such as VTS and AIS. In the last part of paper, there are results of studies which indicate high resistance to most common collusion attacks. Method proposed by authors can enhance the security of visual data transmission in vessel traffic systems.

Improvement in Accuracy of Determining a Vessel’s Position with the Use of Neural Networks Ana Robust M-Estimation

Abstract In the 21st century marine navigation has become dominated by satellite positioning systems and automated navigational processes. Today, global navigation satellite systems (GNSS) play a central role in the process of carrying out basic navigational tasks, e.g. determining the coordinates of a vessel’s position at sea. Since satellite systems are being used increasingly more often in everyday life, the signals they send are becoming more and more prone to jamming. Therefore there is a need to search for other positioning systems and methods that would be as accurate and fast as the existing satellite systems. On the other hand, the automation process makes it possible to conduct navigational tasks more quickly. Due to the development of this technology, all kinds of navigation equipment can be used in the process of automating navigation. This also applies to marine radars, which are characterised by a relatively high accuracy that allows them to replace satellite systems in performing classic navigational tasks. By employing M-estimation methods that are used in geodesy as well as simple neural networks, a software package can be created that will aid in automating navigation and will provide highly accurate information about a given object’s position at sea by making use of radar in comparative navigation. This paper presents proposals for automating the process of determining a vessel’s position at sea by using comparative navigation methods that are based on simple neural networks and geodetic M-estimation methods.

Application of Square Msplit Estimation in Determination of Vessel Position in Coastal Shipping

Abstract The main aim of this paper is to assess the possibility of using non-conventional geodetic estimation methods in maritime navigation. The research subject of this paper concerns robust determination of vessel’s position using a method of parameters estimation in the split functional model (Msplit estimation). The studies performed will help in finding out if and in which situations the application of Msplit estimation as the method for determining vessel’s position is beneficial from the perspective of navigation safety. The results obtained were compared with the results of traditional estimation methods, i.e. least squares method and robust M-estimation.

A Vessel's Mathematical Model and its Real Counterpart: A Comparative Methodology Based on a Real-world Study

Navigation and manoeuvring simulators are increasingly being used in research centres to conduct complex navigation experiments and analyses. The structure and capabilities of simulation software make it possible to reproduce any conditions, including weather conditions. The complex mathematical models of marine environmental conditions that are being implemented nowadays take into account various sea wave models, which makes simulation tests more realistic. This paper deals with issues related to evaluating and verifying vessel simulation models based on real-world studies. As a result of the present research project, a methodology for comparing vessel simulation models with their real-life counterparts was developed. A measurement platform was created for the purpose of carrying out real-world studies; it is available at the Institute of Marine Navigation and Hydrography of the Polish Naval Academy. One important research step involved developing a procedural algorithm for making real-world measurements. This paper presents the results of using this platform in comparative tests of the manoeuvring elements of real and simulated vessels.

Methodology of Creation the Simulation Basin based on the Projected Canal through the Vistula Spit

Abstract The biggest problem in the process of implementation of the new sea areas project or aids to navigation systems is to check the assumptions without compromising security on real waters. Today, digital models are available for easy and inexpensive replacement of the research methods used so far. For this purpose the navigational and maneuvering simulators are perfect. Simulators as a research tools allow you to define a more realistic and accurate data for the study and evaluation sea areas. The purpose of the simulation is to identify and reduce the risk for seafarers during navigation on the waterways, canals and port areas. These include quantitative and qualitative assessment of the canals and fairways construction. The main requirement for a simulation system is to have a multi-task simulation software, which includes effective tools for repositioning and designing safe waterways and port infrastructure. The Institute of Navigation and Maritime Hydrography of the Polish Naval Academy since the eighties of the twentieth century is carried out projects in the field of navigational and hydrographic support of human activities at sea. This is possible thanks to the extensive set of simulation tools. Planning this tasks in a simulators software environment allow not only to design of virtual counterparts of real sea areas, but also to evaluate the quality of manufactured parts before their actual exposure to sea areas.

EVALUATION OF VESSEL SIMULATION MODEL COMPATIBILITY WITH ITS EQUIVALENT IN REALITY

ABSTRACT Complex simulation systems are often used in order to enhance the safety level on newly designed navigation areas and to facilitate their verification process. The application of these systems supersedes older methods based on manoeuvring basins, wherein models minified in particular scales were used. Modern methods are definitely cheaper and require less work. The paper presents the method of assessment of the compatibility of a ship simulation model with its real counterpart. Access to the simulator’s components responsible for creating and editing bodies of water as well as ship models gives the possibility of their verification. Using cutting-edge navigation systems such as inertial systems, weather stations and GPS gives the possibility of obtaining indispensable information about ship’s behaviour under certain hydro-meteorological conditions. STRESZCZENIE Złożone systemy symulacyjne są często używane dla poprawy poziomu bezpieczeństwa na etapie projektowania nowej infrastruktury nawigacyjnej, jak również dla ułatwienia procesu ich weryfikacji. Stosowanie tych systemów zastępuje starsze metody oparte na pomniejszonych modelach fizycznych i basenach modelowych, w których je testowano. Nowoczesne metody są zdecydowanie tańsze i wymagają mniej pracy. Artykuł przedstawia metodę oszacowania zgodności modelu symulacyjnego statku z jego rzeczywistym odpowiednikiem. Dostęp do komponentów symulatora odpowiedzialnych za tworzenie i modelowanie akwenu oraz modele statku daje możliwość ich sprawdzania. Jest to możliwe dzięki użyciu najnowszych systemów nawigacyjnych, takich jak systemy inercjalne, stacje meteorologiczne i GPS, które umożliwiają otrzymywanie niezbędnej informacji o zachowaniu się statku w konkretnych warunkach hydrometeorologicznych.