Performance Bounds for VDES R-mode

The Very High Frequency (VHF) Data Exchange System (VDES) is a new radio communication system being developed by the international maritime community, with the principal objectives to safeguard existing Automatic Identification System (AIS) core functions and enhance maritime communication applications, based on robust, efficient and secure data transmission with wider bandwidth than the AIS. VDES is also being considered as a potential component of the R-mode concept, where the same signals used for communication are also used for ranging, thus mitigating the impact of disruptions to satellite positioning services. This paper establishes statistical performance bounds on the ranging precision of VDES R-mode, assuming an additive white Gaussian noise propagation channel. Modified Cramér-Rao bounds on the pseudorange estimation error are provided for all waveforms currently proposed for use in terrestrial VDES communications. These are then used to estimate the maximum usable ranges for AIS/VDES R-mode stations. The results show that, under the assumed channel conditions, all of the new VDES waveforms provide better ranging performance than the AIS waveform, with the best performance being achieved using the 100 kHz bandwidth terrestrial VDE waveforms.

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Influence of Aircraft Power Electronics Processing on Backup VHF Radio Systems

Electronics ◽

10.3390/electronics10070777 ◽

2021 ◽

Vol 10 (7) ◽

pp. 777

Author(s):

Jan Leuchter ◽

Radim Bloudicek ◽

Jan Boril ◽

Josef Bajer ◽

Erik Blasch

Keyword(s):

Power Electronics ◽

Electromagnetic Interference ◽

Communication Systems ◽

Electromagnetic Compatibility ◽

Intermediate Frequency ◽

Radio Communication ◽

Very High Frequency ◽

Switching Power ◽

Radio Systems ◽

The Impact

The paper describes the influence of power electronics, energy processing, and emergency radio systems (ERS) immunity testing on onboard aircraft equipment and ground stations providing air traffic services. The implementation of next-generation power electronics introduces potential hazards for the safety and reliability of aircraft systems, especially the interferences from power electronics with high-power processing. The paper focuses on clearly identifying, experimentally verifying, and quantifiably measuring the effects of power electronics processing using switching modes versus the electromagnetic compatibility (EMC) of emergency radio systems with electromagnetic interference (EMI). EMI can be very critical when switching power radios utilize backup receivers, which are used as aircraft backup systems or airport last-resort systems. The switching power electronics process produces interfering electromagnetic energy to create problems with onboard aircraft radios or instrument landing system (ILS) avionics services. Analyses demonstrate significant threats and risks resulting from interferences between radio and power electronics in airborne systems. Results demonstrate the impact of interferences on intermediate-frequency processing, namely, for very high frequency (VHF) radios. The paper also describes the methodology of testing radio immunity against both weak and strong signals in accordance with recent aviation standards and guidance for military radio communication systems in the VHF band.

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Improving Near Miss Detection in Maritime Traffic in the Northern Baltic Sea from AIS Data

Journal of Marine Science and Engineering ◽

10.3390/jmse9020180 ◽

2021 ◽

Vol 9 (2) ◽

pp. 180

Author(s):

Lei Du ◽

Osiris A. Valdez Banda ◽

Floris Goerlandt ◽

Pentti Kujala ◽

Weibin Zhang

Keyword(s):

Baltic Sea ◽

Perceived Risk ◽

Maritime Transportation ◽

Near Miss ◽

Automatic Identification ◽

Identification System ◽

Collision Risk ◽

Ship Collision ◽

The Impact ◽

Ship Behavior

Ship collision is the most common type of accident in the Northern Baltic Sea, posing a risk to the safety of maritime transportation. Near miss detection from automatic identification system (AIS) data provides insight into maritime transportation safety. Collision risk always triggers a ship to maneuver for safe passing. Some frenetic rudder actions occur at the last moment before ship collision. However, the relationship between ship behavior and collision risk is not fully clarified. Therefore, this work proposes a novel method to improve near miss detection by analyzing ship behavior characteristic during the encounter process. The impact from the ship attributes (including ship size, type, and maneuverability), perceived risk of a navigator, traffic complexity, and traffic rule are considered to obtain insights into the ship behavior. The risk severity of the detected near miss is further quantified into four levels. This proposed method is then applied to traffic data from the Northern Baltic Sea. The promising results of near miss detection and the model validity test suggest that this work contributes to the development of preventive measures in maritime management to enhance to navigational safety, such as setting a precautionary area in the hotspot areas. Several advantages and limitations of the presented method for near miss detection are discussed.

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Comprehensive Analysis of Automatic Identification System (AIS) Data in Regard to Vessel Movement Prediction

Journal of Navigation ◽

10.1017/s0373463314000253 ◽

2014 ◽

Vol 67 (5) ◽

pp. 791-809 ◽

Cited By ~ 32

Author(s):

Philipp Last ◽

Christian Bahlke ◽

Martin Hering-Bertram ◽

Lars Linsen

Keyword(s):

Large Data ◽

Automatic Identification ◽

Identification System ◽

Very High Frequency ◽

Database Queries ◽

Related Data ◽

Movement Prediction ◽

Time Period ◽

Current Usage ◽

Exchange Vessel

AIS was primarily developed to exchange vessel-related data among vessels or AIS stations by using very-high frequency (VHF) technology to increase safety at sea. This study evaluates the formal integrity, availability, and the reporting intervals of AIS data with a focus on vessel movement prediction. In contrast to former studies, this study is based on a large data collection of over 85 million AIS messages, which were continuously received within a time period of two months. Thus, the evaluated data represent a comprehensive and up-to-date view of the current usage of AIS systems installed on vessels. Results of previous studies concerning the availability of AIS data are confirmed and extended. New aspects such as reporting intervals are additionally evaluated. Received messages are stored in a database, which allows for performing database queries to evaluate the obtained data in an automatic way. This study shows that almost ten years after becoming mandatory for professional operating vessels, AIS still lacks availability for both static and dynamic data and that the reporting intervals are not as reliable as specified within the technical AIS standard.

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Securing the Automatic Identification System (AIS): Using public key cryptography to prevent spoofing whilst retaining backwards compatibility

Journal of Navigation ◽

10.1017/s0373463321000837 ◽

2021 ◽

pp. 1-13

Author(s):

Gareth Wimpenny ◽

Jan Šafář ◽

Alan Grant ◽

Martin Bransby

Keyword(s):

Data Exchange ◽

Situational Awareness ◽

Public Key Cryptography ◽

Satellite System ◽

Public Key ◽

Automatic Identification ◽

Identification System ◽

Automatic Identification System ◽

Safe Navigation ◽

Global Navigation Satellite

Abstract The civilian Automatic Identification System (AIS) has no inherent protection against spoofing. Spoofed AIS messages have the potential to interfere with the safe navigation of a vessel by, amongst other approaches, spoofing maritime virtual aids to navigation and/or differential global navigation satellite system (DGNSS) correction data conveyed across it. Acting maliciously, a single transmitter may spoof thousands of AIS messages per minute with the potential to cause considerable nuisance; compromising information provided by AIS intended to enhance the mariner's situational awareness. This work describes an approach to authenticate AIS messages using public key cryptography (PKC) and thus provide unequivocal evidence that AIS messages originate from genuine sources and so can be trusted. Improvements to the proposed AIS authentication scheme are identified which address a security weakness and help avoid false positives to spoofing caused by changes to message syntax. A channel loading investigation concludes that sufficient bandwidth is available to routinely authenticate all AIS messages whilst retaining backwards compatibility by carrying PKC ‘digital signatures’ in a separate VHF Data Exchange System (VDES) side channel.

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Comprehensive Assessment of Automatic Identification System (AIS) Data Application to Anti-collision Manoeuvring

Journal of Navigation ◽

10.1017/s0373463314000897 ◽

2015 ◽

Vol 68 (4) ◽

pp. 697-717 ◽

Cited By ~ 16

Author(s):

Andrzej Felski ◽

Krzysztof Jaskólski ◽

Paweł Banyś

Keyword(s):

Collision Avoidance ◽

Ship Motion ◽

Supplementary Information ◽

Automatic Identification ◽

Identification System ◽

Radio Communication ◽

Dynamic Information ◽

Automatic Identification System ◽

Ideal System ◽

Motion Parameters

The use of radar information for collision avoidance is common, however it is effective only for constant values of ship motion parameters. As information delays or information errors occur, it is reasonable to supplement the information derived from radar with another information system. An ideal system should operate automatically and continuously. A system that appears to be suitable to provide this kind of information is the Automatic Identification System (AIS), which may be classified as a radio communication system that uses radio waves to transmit data with regard to ship motion parameters. In this paper the topic of integrity and completeness of AIS information is discussed and the research results for the completeness and integrity of dynamic information are presented. In addition, the outcomes of AIS information correctness from the Gulf of Gdańsk were compared with studies carried out in the Baltic Sea, east of Bornholm, between Trelleborg and Arkona. The results of research for AIS dynamic information with the highest completeness (Position, Course over Ground and Speed over Ground) are presented. The research outcomes presented in the paper lead to the conclusion that AIS could deliver useful supplementary information in the process of collision avoidance.

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Assessing the Impact of Disruptive Events on Port Performance and Choice: The Case of Gothenburg

Journal of Marine Science and Engineering ◽

10.3390/jmse9020145 ◽

2021 ◽

Vol 9 (2) ◽

pp. 145

Author(s):

Martin Svanberg ◽

Henrik Holm ◽

Kevin Cullinane

Keyword(s):

Performance Metrics ◽

Automatic Identification ◽

Identification System ◽

Container Port ◽

Medium Term ◽

Short Term ◽

Labour Dispute ◽

Container Ports ◽

The Impact ◽

The Relationship

This paper assesses the impact of a major disruptive event at the port of Gothenburg, Scandinavia’s largest container port. Automatic Identification System (AIS) data is analyzed, in combination with official port statistics on container handling in the four main container ports in Sweden, from 2014–2018. Particular attention is paid to the relationship between container volumes handled and calculated performance metrics at the specific times of the intense labour dispute at the port of Gothenburg during the periods Q2 (2016) and Q4 (2016)–Q2 (2017). The paper concludes that the decline in container volumes handled at Gothenburg over the period is specifically due to fewer ships calling at the port following each of the intense periods of the labour dispute. It is also concluded that the effect on competitor ports in the region were significant in terms of both increased volumes of gateway container traffic and the resulting short-term and medium term impacts on both port user profiles and port efficiency levels.

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The Methodology for Assessing the Impact of Offshore Wind Farms on Navigation, Based on the Automatic Identification System Historical Data

Energies ◽

10.3390/en14206559 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6559

Author(s):

Krzysztof Naus ◽

Katarzyna Banaszak ◽

Piotr Szymak

Keyword(s):

Wind Farm ◽

Wind Farms ◽

Offshore Wind ◽

Automatic Identification ◽

Identification System ◽

Large Set ◽

Data Set ◽

Offshore Wind Farms ◽

Automatic Identification System ◽

The Impact

Mounting offshore renewable energy installations often involves extra risk regarding the safety of navigation, especially for areas with high traffic intensity. The decision-makers planning such projects need to anticipate and plan appropriate solutions in order to manage navigation risks. This process is referred to as “environmental impact assessment”. In what way can these threats be reduced using the available Automatic Identification System (AIS) tool? This paper presents a study of the concept for the methodology of an a posteriori vessel traffic description in the form of quantitative and qualitative characteristics created based on a large set of historical AIS data (big data). The research was oriented primarily towards the practical application and verification of the methodology used when assessing the impact of the planned Offshore Wind Farm (OWF) Baltic II on the safety of ships in Polish Marine Areas, and on the effectiveness of navigation, taking into account the existing shipping routes and customary and traffic separation systems. The research results (e.g., a significant distance of the Baltic II from the nearest customary shipping route equal to 3 Nm, a small number of vessels in its area in 2017 amounting to only 930) obtained on the basis of the annual AIS data set allowed for an unambiguous and reliable assessment of the impact of OWFs on shipping, thus confirming the suitability of the methodology for MREI spatial planning.

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Issues of building an intelligent water transport management system

E3S Web of Conferences ◽

10.1051/e3sconf/202132600029 ◽

2021 ◽

Vol 326 ◽

pp. 00029

Author(s):

Artem Butsanets ◽

Evgeniy Ol’Khovik ◽

Vladimir Karetnikov ◽

Victor Senchenko

Keyword(s):

Information System ◽

Geographical Information System ◽

Route Planning ◽

Geographical Information ◽

Transport Systems ◽

Automatic Identification ◽

Identification System ◽

Data Types ◽

Very High Frequency ◽

Analyse Data

The current level of technology in terms of instruments, devices and software enables the construction of local intelligent transport systems that contribute to the prevention of accidents. It has become possible to build crewless and unmanned vessels. Geographical information services such as Google Maps, Mapbox, OpenStreetMap have already shown their effectiveness. The relevance of the study stems from the possibility to partially automate ship’s route planning nowadays. As navigation monitoring is carried out by means of VHF (very high frequency) - Automatic Identification System (AIS) receivers, the authors propose to collect and analyse data. However, for the construction of the geographical information system and data processing, the authors justified the proposal to build the concept, methodological foundations, mathematical models and scenarios, which will serve as the basis for the development of software for the geographical information system. They propose data types for constructing time/speed matrices for planning optimal routes based on the current navigational situation. The data collected will provide a 12-36 hour forecast and allow for the determination of vessel speeds and times, considering vessel specifications, traffic of other vessels, queue at locks, forecast of hydro- and meteorological conditions, estimates of traffic intensity and density. The service is expected to optimise the route in terms of speed and journey time to meet the transport and logistics challenge.

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Software and technological complex of identification of sea vessels based on the use of radar space images Sentinel 1

Ukrainian journal of remote sensing ◽

10.36023/ujrs.2021.8.4.205 ◽

2021 ◽

Vol 8 (4) ◽

Author(s):

Anatolii Kuzmin ◽

Leonid Grekov ◽

Georgii Veriuzhskyi ◽

Oleksii Petrov

Keyword(s):

Speckle Noise ◽

Sea Surface ◽

Automatic Identification ◽

Identification System ◽

Space Images ◽

Probability Of Error ◽

Technological Complex ◽

Local Background ◽

Evaluation Of Parameters ◽

The Impact

The paper considers the problem of using images from SAR satellites for the identification of seagoing vessels. It describes the main functions of software and technological complex of the automated monitoring. The system is operated with utilizing space images of SAR satellites Sentinel 1A (B). The algorithmic part, which implements the detection on the sea surface the marks associated with ships, is described in details. To reduce the impact of speckle-noise, the image is pre-processed with the improved Lee-filter. Further processing lies in using an adaptive threshold algorithm that provides detection for each local background fragment of the image the unusually bright pixels, at the same time the algorithm provides a constant probability of error. By solving a nonlinear equation, for each position of the background window the algorithm finds the threshold brightness value and then all pixels above this value are considered vessels. In advance the evaluation of parameters of statistical distribution of pixels’ brightness is performed for each position of the background window. K-mean is used for such distribution. The selected bright pixels are combined into compact groups and their size and coordinates are being determined. The obtained results are compared with the data of the AIS, Automatic Identification System of ships, and the results are displayed on a cartographic basis.

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A Model of OFDM based Maritime VHF Communication System for Data Exchange

Polish Maritime Research ◽

10.2478/pomr-2018-0051 ◽

2018 ◽

Vol 25 (2) ◽

pp. 27-36

Author(s):

Sanjin Valčić ◽

Tibor Pogány ◽

Zoran Mrak

Keyword(s):

Communication System ◽

Orthogonal Frequency Division Multiplexing ◽

Data Exchange ◽

Simulation Models ◽

Automatic Identification ◽

Very High Frequency ◽

Ofdm Modulation ◽

Data Rates ◽

Validation Parameters ◽

Very High

Abstract In the maritime Very High Frequency (VHF) band, there are no systems for transmitting large amounts of data. Therefore, it is necessary to develop new systems that would modernize the Global Maritime Distress and Safety System (GMDSS), significantly relieve the Automatic Identification System’s (AIS) communication channels, and set guidelines for the development of communication infrastructure of the e-Navigation. In line with this, analytical and simulation models of the maritime VHF data transmission communication system using Orthogonal Frequency Division Multiplexing (OFDM) modulation are worked out in this paper. The achieved data rate, the spectral efficiency and the bit error rate (BER) represent validation parameters on which the results of the analytical and simulation models are evaluated. It is concluded that the application of the digital OFDM modulation in the maritime VHF band may improve the GMDSS system by achieving higher data rates compared to the current terrestrial mandatory systems for data exchange, i.e. Digital Selective Calling (DSC) and AIS.

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