Wyniki wyszukiwania - BazTech

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A study to determine the most effective daymark shape for a leading line

Ahmad Fuad A F., Adlan D. A. A., Kamis A. S., Ahmad A. S.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2022

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Vol. 16 No. 3

497--500

EN

The use of daymark shapes for leading lines include its visual shape and symbol, to aid sailors who need to navigate safely through a marked narrow channel. The shapes which are currently used are rectangles, diamonds, and triangles. However, there is not much information on which shape is the most effective for navigational referencing. Therefore, the main objective of this research is to determine the most effective shape for a leading line daymark. The Kemaman Port was used as an area of interest to model the three-dimensional simulation. The size and height of the leading line daymark was calculated based on the dimensions of the navigational channel obtained from the Kemaman Port navigation chart. The simulation for different shapes of the leading mark in the same area was developed using a three-dimensional software. Experts were engaged to evaluate the effectiveness of each daymark shape across the maximum and minimum distances during the simulation run. Results showed that the diamond shape daymark was relatively better identified and used as reference, compared to other shapes in the same range due to its relatively larger surface area. Therefore, the study objective was achieved, and the results can be used to improve marine navigation safety.

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Analiza infrastruktury nawigacyjnej w kontekście oceny bezpieczeństwa nawigacyjnego w delcie Wisły i na Zalewie Wiślanym

Rutkowski G.

Zeszyty Naukowe Akademii Marynarki Wojennej

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2010

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R. 51 nr 1 (180)

51-63

PL

Niniejszy artykuł obejmuje analizę infrastruktury nawigacyjnej w kontekście oceny bezpieczeństwa nawigacyjnego oraz możliwości uprawiania żeglugi w delcie Wisły i na Zalewie Wiślanym. W artykule zaproponowano sposób oceny bezpieczeństwa żeglugi (ryzyka nawigacyjnego) w akwenie ograniczonym z wykorzystaniem przestrzennego modelu domeny statku.

EN

The paper deals with the navigational infrastructure analysis with respect to safety of navigation in the mouth of the Vistula River. In this paper the author also presents methods that can be used for estimating safety of navigation (navigational risk) in the restricted sea areas by means of the model of the ship’s domain. The essence of the method suggested in the thesis is the systematic approach to sea vessel operation in the aspect of estimating its safety when navigating in restricted sea areas.

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Positioning with interactice navigational structure implementation

Czaplewski K.

Annual of Navigation

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2004

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No. 7

1--119

EN

The most essential outcome of theoretical studies and selected numerical analyses, presented in this work, are the suggestions related to the technology of producing and working out the results of observations, carried out in the Interactive Navigational Structures. Implementing such a Structure into navigation practice will enable supporting the positioning process by taking use of objects, which until present, in classic navigation, have been omitted due to a lack of information about their coordinates. Establishing and dynamic developing the Interactive Navigational Structures is of special importance, in case the available positioning systems appear insufficient (e.g. in submarine navigation or any work of special character). IANS can be based on various systems and navigational observations, including the satellite GPS systems. Selection of an observational model, accommodated to any current navigational situation, is simplified owing to the decisive functions, recommended in the work; applying the above functions, in conjunction with the functions of attenuation, has resulted in making more efficient the process of estimation, robust for out-lying observations. Due to diversity of the observations sets and the "by stages" way of working them out, the estimation is of sequential character (sequential robust estimation). The adjustment task, formulated and resolved in this work, has been related to the method and adjusted to the IANS chain being under development. The fundamental elements of this task's function of target are, the suggested in the work, the equivalent-decisive covariance matrix and equivalent-decisive weights matrix, both connected by statistical model. The method of identification of not only out-lying observations but also out-lying adjustment points and neutralization of an influence thereof is also advised in the work; the method has been resulted from free adjustment and M-estimation principles. The method, named hybrid M-estimation, can make a great difference specially in extreme navigation conditions, carried out basing intensely on points of the set R. The numerical tests, described in Chapter 6, refer to simulation of elementary navigational situations, connected with developing IANS and using thereof. They are to illustrate principal properties of the suggested conceptions. The results of the first of the tests have confirmed a possibility of taking use of the recommended structures in some special tasks of navigation at sea. Extremely interesting properties (the second test), first of all those of robust character, were revealed by hybrid M-estimation. The obtained results have proved that there is a chance to carry out reliable navigation, being compelled only to applying of IANS. The presented conceptions have been basically completed in respect of the theory concerning establishing, developing and mathematical working out the Interactive Navigational Structures. However, the work is incomprehensive in regard to practical implementation of the displayed models. For example, there is a possibility to use the described structures in submarine navigation. A lack of any classic navigational systems in sea depth has been forcing to seek new solutions, as the Interactive Navigational Structure is. The above solutions may also be extensively employed in radar navigation. Radar observations are often biased with gross errors, caused by radar echo generation technique. The robust estimation, if applied in the version presented in this work, may significantly improve final determinations' standard. The recommended mathematical models and methods of their parameters evaluation are applicable to maritime navigation under a certain condition. The available at present nautical information about navigational signing elements should be complemented. All the suggested solutions may not be in today's situation fully exercised (especially hybrid M-estimation) due to a lack of information about covariance matrixes or at least about errors of determining coordinates of stable and floating navigational signs, embraced by any optional navigational system.