PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 8

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available AIS R-mode trilateration for GPS positioning and timing insurance
Shyshkin O. V., Konovets V. I., Koshevyy V. M.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2024
|
Vol. 18 No. 2
369--374
EN
Satellite navigation is the backbone of maritime navigation today. However, the technical vulnerability of on-board Global Navigation Satellite System (GNSS) receivers the satellite system greatly destabilizes maritime security due to the loss of ship’s position and accurate time. This article devoted to study an alternative method for obtaining coordinates and accurate time based on the use of automatic identification system (AIS) radio channels, so-called range mode (R-Mode). We use other AIS ship stations with reliable position data as reference stations and determine time of arrival for received AIS transmissions. To improve the accuracy of measuring signal arrival instance in the time difference of arrival (TDOA), that we utilize for trilateration, it is proposed signal oversampling and applying the fast Fourier transform (FFT) to the product of quadrature components of the baseband Gaussian minimum shift keying (GMSK) signal in the window of AIS time slot. To take into account the movement of other ships, appropriate coordinate corrections are foreseen, which can be calculated by dead reckoning or by the inertial navigation system of our ship. The proposed method is fully compatible with the existing AIS signals and may be employed in critical situations of locally limited (jamming, spoofing) GNSS abilities. It can be implemented as a separate unit, working for receiving in parallel with the mandatory AIS transponder.
2
Content available SMART digital selective calling user interface on the base of Integration maritime navigation and radiocommunication equipment
Koshevyy V. M., Konovets V. I., Shyshkin O. V.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2021
|
Vol. 15 No. 2
291--297
EN
High level solution S4 of the IMO E-navigation Strategy Implementation Plan provides integration and presentation of available information in graphical displays received via communication equipment. At the same time, the problem of the correct application of digital selective calling (DSC) operational procedures in navigation practice has existed since the introduction of the GMDSS and requires a solution. This problem may be resolved on the base of integration maritime navigation and radiocommunication equipment. The article proposes approach for practical realization of this integration by implementing a SMART (specific, measurable, assignable, realistic, and timely) DSC interface within S4. Using this approach the practical realisation integration of AIS – DSC – Information display was implemented. It makes possible implementation of user-friendly human-machine interface (HMI) for navigator. An experimental prototype of communication graphical interface is designed, which allows effective decision-making on radio communication control/monitoring. The use IEC 61162-1/2 (Maritime navigation and radiocommunication equipment – Digital interfaces) data transfer provides standard inter-module connections and eliminates the negative impact of the equipment diversity from different manufacturers by means uniform HMI implementation.
3
Content available GPS Synchronization of audio watermarks in the Maritime Automatically Identified Radiotelephony
Shyshkin O. V., Koshevyy V. M., Ryaboshapka I. V.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2021
|
Vol. 15 No. 2
307--312
EN
Audio watermarking (AW) technology in cooperation with GPS synchronization of watermarked frames is proposed for application in the maritime VHF communication for automatic identification of radiotelephone messages. Automatic identification ensures efficient messaging from the very beginning of a radio transmission, while eliminating the human factor inherent in voice identification. AW refers to inaudible embedding of additional data just into the post microphone signal, using standard marine installations without any additional radio channel resources. The designed algorithm is based on data embedding in the Fast Fourier Transform domain with the rate of 32 bit/s. The experimental prototype of the device is designed on the base of micro-controller development kit 32F429IDISCOVERY and GPS module NEO-6M-0-001. Designed system, applied for automatic ship’s identification, provides the full compatibility with the existing radio installation, and does not require replacement of standard VHF transceivers and operational procedures. Besides automatic identification the system may be used in the special applications, for example, by the threat of terrorist attack; generally contributes to navigation safety and information security.
4
Content available Developments of Interface for VHF, MF/HF Communication Using DSC in GMDSS Services in the Framework of E-navigation Concept
Koshevyy V. M., Shyshkin O. V.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2021
|
Vol. 15 No. 3
593--600
EN
It is proposed the description of interface for VHF/MF/HF for simplification of DSC communication for implementation in the frame of conception developments in GMDSS services, applied to Maritime Mobile Services. This interface is realized within its integration with INS by an appropriate way on the base of common communication protocol for all three DSC communication sub bands in standardized and harmonized format and significantly simplifies the DSC user interface. It is very important for application in Maritime services, including GMDSS services, VTS services and SAR service. Suggested approach for improving DSC communication is based on the three main outputs of e-navigation strategic direction development related to the integration of communication and navigation equipment/systems, including standardized mode of operation. Implementation of the standardization demands to include in this integration the satellite AIS system. The feasibility of the proposal is supported by the existence of relevant IEC standards and IMO documents.
5
Content available Antenna for marine radar with supperdirectivity properties
Koshevyy V. M., Shevchenko A. A.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2020
|
Vol. 14, no. 2
317--324
EN
The reception antenna diagram side lobe’s level suppression algorithm for marine radar by means of antenna array with only a few tuning elements of antenna array is considered. The others no tuning elements of array are choosing for obtain a given value of average side lobe level suppression and with given value of antenna directivity without using of numerical optimization procedures. Special algorithm of interaction of these no tuning elements for realizing Supperdirectivity properties is used. The structural diagram of array is presented. The efficiency of suggested design has been investigated.
6
Content available The Development of Iteration Method for Optimization of Pair "Signal-filter"
Koshevyy V.M., Gorishna I.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2018
|
Vol. 12, no. 3
541--544
EN
This paper is devoted to the improvement of the working methods of the "signal-filter" pair using an iterative procedure to maximize the signal-to-noise ratio, namely, to highlight the useful signals to provide information about the environment during the adaptive radar sensing in the conditions of obstacles. An algorithm for determining the optimal filter for suppressing undesired side lobes is proposed, which allows improving the process of detection and identification the target objects. Qualitative characteristics and the stages of space-time signal processing in the radar were justified under correlation conditions (ССF) between the received and expected signals. The using of probing radar signals, shortened in their duration were proposed in order to reduce the power of reflections from the underlying surface and increase the contrast of the radar image. A simulation test of the developed methodology was carried out in order to confirm the reliability of the proposed algebraic expressions using a mathematical model implemented in the Matlab programming environment, and a conclusion is drawn about the practical quality of the technical solutions developed on the basis of the iteration method.
7
Content available Synthesis of Binary Group-Complementary Sequences
Koshevyy V.M.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2018
|
Vol. 12, no. 3
545--548
EN
Algorithm of binary {-1, 1} group-complementary sequences direct construction for any sequences length N is suggested. On the base of these sequences the signals with very wide frequency bandwidth may be constructed (up to the ultra wideband (UWB) signals). Synthesized sequences may found their application in radar and communication.
8
Content available The Selection of Signals for Continuous Wave Radar which Reduce the Sensitivity to Doppler Shift of Frequencies
Koshevyy V.M., Koshevyy I.V., Dolzhenko D.O.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2016
|
Vol. 10, no. 1
125--129
EN
The signals with ideal correlation properties are of interest for continuous wave radar. At the same time it’s important to provide low sensitivity to Doppler shifts of frequencies. There were considered signals with special structure due to amplitude modulation which provide capability of radar work with Search and Rescue Transponder (SART). Because the amplitude modulation has a drawback – not efficient use of signal energy, in a class of proposed signals there were considered signals with uniform amplitude. The mismatched filtering may be used by means special weighting functions for obtaining the necessary correlation properties.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.