In the paper, the measurement and simulation results of the VDES (VHF Data Exchange System) terrestrial component are discussed. It is anticipated that VDES will be one of the major solutions for maritime communications in the VHF band and its performance will be sufficient to fulfill the requirements of the e-navigation applications. The process of the VDES standardization (ITU R, IALA) has not been officially completed yet, but substantial amount of technical information about the future system’s terrestrial component (VDE-TER) is already available. The paper is divided into three general parts: (a) theoretical presentation of the system’s physical layer and the radio channels applicable to VDES, (b) simulation results (BER, BLER, channel delay between two propagation paths and its influence on bit rates) and (c) measurement results (useful ranges, BER). It turned out that in real maritime conditions, the VDES system can offer ranges between 25 and 38 km for the configurations assumed during the measurement campaign. Those results are generally compliant with the theoretical data in the line-of-sight conditions. In the NLOS scenarios, where fading becomes the dominant phenomenon, the discrepancies between the measurements and the theoretical results were more significant. The obtained results confirmed that VDES provides a large coding gain, which significantly improves the performance of data transmission and increases the bit rate compared to the existing maritime radiocommunication solutions. It should be noted that the results presented in the article were used by the IALA while developing the current version of the VDES specification.

This article presents the work conducted in the R-Mode Baltic project, which aims to launch the R-Mode demonstrator in the Baltic Sea area. The article describes the concept of the Automatic Identification System (AIS) infrastructure and VHF Data Exchange System (VDES) signal utilization with respect to their potential role in the future R-Mode System. It also contains the analysis of the distance determination accuracy in the designed system based on calculation of the correlation between the received signal and the known transmitted signal, as well as the achievable ranges for various system configurations. Additionally, the paper discusses the implementation of the test-bed transmitter and receiver, the methodology of measurement campaigns carried out in the Baltic Sea on the Gdynia-Karlskrona route, as well as the obtained results. The collected measurement results were thoroughly analyzed and compared with theoretical values. The summary contains conclusions, as well as the plans for the next phase of measurement research.

This article discusses several aspects related to the modeling of the radio channel in the wind farm propagation environment. The first part of the article is filled with the analysis of the ITU-R BT.1893-1 model, which—as will be shown—is also applicable to systems operating in the VHF and UHF bands. The conducted measurement campaign makes it possible to model a radio channel for VHF operating systems in the wind farm propagation environment. Thanks to the obtained results, the authors propose the VHF radio channel model for that environment. Using the software implementation of this model, the authors carry out a detailed simulation analysis of the impact of wind turbines on radio systems operating in the VHF band. The main motivation for this work is the growing importance of the offshore wind energy in general, numerous investments in that area in Poland, and the lack of existing mathematical models regarding the wind farms’ impact on the VHF systems. The VHF band is of special interest here, as this part of the spectrum is utilized by numerous marine administration and border protection radio systems, which can be adversely affected by the wind turbines (due to interference and/or radio shadowing).

The article presents an analysis of the features of selected correlators impacting the accuracy of determining the receiver’s range and position in VHF marine environment. The paper introduces the concept of various correlators – including the double delta correlator – and describes the proposed measurement scenarios that have been designed to demonstrate the effectiveness of those components. The entire work was performed as part of the R-Mode Baltic and R-Mode Baltic 2 projects, with our goals including analyzing the impact of multipath phenomena, changes in the sampling frequency or Signac type on the determination of the received signal delay at the receiver. The measured data were processed in a signal correlation application and in a TOA-based tool in order to determine the receiver’s position. This process made it possible to compare the selected correlating devices. The results presented in this article are to be used by IALA in developing a current version of the VHF data exchange system’s (VDES) specification.

This article discusses several aspects related to modeling the impact of offshore wind farms on maritime radar systems operating in the X and S bands. The first part of the paper focuses on theoretical models and analyses, taking into account radio shadowing and false radar echoes. Additionally, the issue of spatial modeling of wind turbines, with diffraction phenomena considered, is reviewed with the help of suitable propagation models. By relaying on a software-based implementation of the proposed model, the authors carried out a detailed simulation of the impact of wind turbines on radar systems operating in the X and S bands. The results of these simulations are presented and discussed in the second part of the article.

As part of the work in the IDSoC project, an innovative framework, using a specialized integrated circuit and software, has been designed, to perform various cryptographic functions, particularly dedicated for use in electronic identification systems with a high level of confidence. All the activities have been carried out in the Common Criteria (CC) regime with the target EAL4+ level, which had a significant impact on the entire organization of work in the project. It is the authors’ goal that once the project’s outputs are finalized, they will successfully undergo the Common Criteria evaluation and certification. This article describes in detail how software component of the dedicated framework was developed – with a particular attention paid to the aspects resulting from the CC requirements. The standards on which the simulator implementation process was based, as well as the assumptions necessary for its initial development phase, are discussed here. It also describes the entire communication process from the first exchange of messages between the card and the inspection system to the end of the message exchange procedure. The paper consists of five parts, starting with an overview of the Common Criteria requirements relevant to this work. After that, the requirements for the inspection system, which is a necessary element for card-terminal communication, have been specified. The implementation concept of the communication simulator was presented along with the discussion of its modules. The methodology of testing the simulator was also introduced. Finally, plans for further development of the project product are described.