Search Results (7)

This paper discusses the impact of wind farms on systems operating in the MF band. The presented material has been gathered by the authors during several measurement campaigns they conducted in recent years on the premises of various land wind farms in northern Poland. The results of this research, however, are particularly important and relevant in the context of offshore wind farms, since several radio systems crucial for safety of navigation and life at sea operate in the MF band, most notably components of the GMDSS. At the time of writing, however, no OWFs existed yet at the Baltic Sea in the Polish Exclusive Economic Zone; therefore, it was not possible to conduct such measurements in the target area under maritime conditions. This article presents the theoretical backgrounds of the topic, and then introduces the results obtained for the lower part of the MF band (DGPS) and the upper part of this band. The results obtained in the latter case can be directly applied to the higher frequencies of the LF band and the lower frequencies of the HF band as well. The results show that the impact of wind farms (in the context of EMF, radio shadowing, and interference) on those bands is minimal or even negligible, which is an important and positive conclusion in the context of extensive development of OWFs in Polish waters scheduled for the next few years. Full article

NAVTEX is a key component in the Global Maritime Distress and Safety System (GMDSS) that automatically transmits urgent maritime safety information such as navigational and meteorological warnings and forecasts to vessels. For the safe navigation of smart ships, this information from different systems should be shared harmoniously in the Common Maritime Data Structure (CMDS). To share NAVTEX messages as CMDS, words in NAVTEX messages must be semantically classified and placed within the CMDS structure. While traditional parsing methods are typically used to understand message semantics, NAVTEX requires natural language processing methods with deep learning due to its unstructured messages. This paper applies six types of Bi-LSTM CRF-based deep learning models to NAVTEX navigational safety messages and analyzes the results to find the most suitable model for understanding the semantics of each word in NAVTEX messages. This technique can be applied to accurately convey the meaning of NAVTEX navigational safety messages to equipment that requires navigational safety information on smart ships without human intervention. Full article

This article uses data generated by Port State Control (PSC) inspections of ships in national ports (Paris MoU) to assess their compliance with radio-communications safety regulations. By mainly applying binary logistic regression methods, the aim is to examine and understand the relationship between the severity of deficiencies in maritime communications and some characteristics of inspected ships. The raw data from the PSC detention database from 2005 to 2022 undergoes post-processing before being analyzed to explore patterns and coincidences with the rest of the potential risk areas. To do so, 23,725 PSC inspections were used. Several classification criteria have been proposed that can better gauge the risk related to distress communications at sea from the dataset. The results connect the probability of detention with the ship age at the inspection date, the flag of the registry, the type of ship, and the location of the port within the countries adhering to the Paris MoU. Another achievement is that the number of PSC inspections of maritime communications in a given period is a better indicator of the risk to safety than the total number of deficiencies detected in these inspections during the same period. This study also explores inspection deficiencies related to competency gaps identified in the Global Maritime Distress Safety System (GMDSS) operators, and precisely using the number of PSC inspections as a criterion of risk for safety is consistent with the recommendations of the Maritime Safety Committee Circular (2006), MSC.1/Circ.1208. Another finding from the time series is that a greater rate of decrease is identified for GMDSS equipment-related deficiencies compared to GMDSS training-related deficiencies. This alone poses a review of the refreshing courses and methods to maintain the General Operator Certificate (GOC) qualification to operate maritime radio communications facilities belonging to the (current and future) GMDSS. Full article

Ship communication systems are defined in one part as GMDSS, while the other part consists of systems with secondary importance in safety communications. Each of these devices and systems makes an independent or separate system that works in a specific frequency range and is, at some level, connected to other communication systems. A step forward regarding frequency range and level of networking can be achieved with the application of a software-defined radio. This paper examines a variety of GMDSS communication equipment in terms of technical discrepancy and frequency range. Furthermore, the software-defined radio and SDR configuration development are described according to their theoretical feasibility in the maritime domain. The paper proposes the concept of SDR-based communication systems quite different from conventional maritime communication systems. This approach, conducted in phases, would in turn ease the upgrading, enable flexibility and inter-operation, prolong system life cycle and integrate different maritime communication systems and devices. The proposed concept aims to develop a centralized communication system to incorporate the ship’s communication devices into one common ship communication system. Full article

This paper analysed the potentialities that have not yet been exploited of the Automatic Vessel Identification System on Medium Frequency (AVISOMEF) that was previously presented to the scientific community. This system expanded the spectrum of possibilities of the Global Maritime Distress and Safety System (GMDSS). By the time AVISOMEF was presented, one of the unexpected benefits was that it could constitute a platform capable of supporting a Maritime Communication Network on Medium Frequency; all remotely located vessels could communicate with each other by using AVISOMEF, making use of the new established network, within the geographic area of implementation, without needing to use satellite techniques. Medium frequency propagation is stable and is not subject to coverage restrictions. To conduct this experiment, we collaborated with the Spanish Maritime Safety Agency (SASEMAR). It was thanks to them that we gathered real-time information about the nationwide maritime traffic that navigated through the Spanish Search and Rescue jurisdiction waters from 2018 to 2020. Full article

Maritime non-commercial communications are performed using the equipment of Global Maritime Distress and Safety System (GMDSS), under the International Convention for the Safety of Life at Sea (SOLAS). This equipment includes numerous devices of different technologies, features and user interfaces, which every officer of the watch (OOW) must know how to use. Besides, the equipment, i.e., its technology has not changed significantly in the last 30 years. Therefore, the purpose of this research was to collect and analyze information on how often GMDSS devices are used and whether any modernization is needed. The main research method was a questionnaire survey intended for experienced officers. Each question, as well as the answers of the respondents, were analyzed in detail and presented graphically. The results of the survey analysis indicate that the VHF (Very High Frequency) radiotelephone, Navigational Telex (NAVTEX) receiver, and Enhanced Group Call (EGC) receiver are still very used, while Digital Selective Calling (DSC) devices and MF/HF (Medium Frequency/High Frequency) radios (telephone and telex) are almost unused onboard. Additionally, more than 80% of respondents believe that GMDSS needs modernization. Full article

Communication for processing relevant information plays a paramount role in developing a comprehensive understanding of Search and Rescue (SAR) situations and conducting operations in a successful and reliable manner. Nevertheless, communication systems have not changed considerably in the context of simplifying very high frequency (VHF) maritime communication and enhancing the value of SAR practices. The Automated Transcription of Maritime VHF Radio Communication for SAR Mission Coordination (ARTUS) project approaches this problem with the development of an assistance system which employs AI-based speech recognition and smart direction finding. First, ideas and specified needs of end users for designing the user interface are presented in this paper. Further, preliminary accomplishments of domain specific language training for maritime speech recognition, and the direction-finding algorithms for localizing senders are sketched out. While the preliminary results build a solid ground, additional field experiments will be conducted in order to enhance the accuracy and reliability of speech recognition and direction finding. The identified end user requirements across different personnel groups show commonalities, but call for a differentiated approach in order to meet the challenges and peculiar needs of the various working contexts. Full article