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Availability of maritime radio beacon signals for R-Mode in the Southern Baltic Sea

Gewies S., Grundhöfer L., Hehenkamp N.

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

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2020

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Vol. 14, no. 1

170--163

EN

This paper presents an overview of the development of a terrestrial positioning system called Ranging Mode (R-Mode) in the Southern Baltic Sea region which utilizes already existing maritime radio infrastructure. Here, an R-Mode testbed is planned to be set up until 2020 that meets maritime user needs for resilient PNT. First measurements of radio beacon signals on-board a vessel sailing in the Southern Baltic Sea show the good availability of beacon signals in this region. A comparison of received signals with a coverage prediction based on the nominal range of radio beacons shows the shortcoming of this approach and emphasizes the need for more elaborated coverage predictions which consider all effects of medium frequency wave propagation at day and night. In the measurements results the skywave has a major impact on the beacon signal stability in the night. The time stability of the signal amplitude seems to be a good indicator for disturbed reception conditions.

2

R-Mode receiver development for medium frequency signals

Grundhöfer L., Gewies S.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2018

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nr 56 (128)

57--62

EN

Signals from Global Navigation Satellite Systems are the primary source for Position, Navigation and Time (PNT) information onboard any vessel today. As these signals are prone to interference, a maritime backup system is needed to provide reliable PNT data, R(anging)-Mode is such a system. It utilizes existing maritime radio beacons or base stations of the Automatic Identification System (AIS) by adding ranging components to the legacy signals. The first modified radio beacons transmit medium frequency (MF) R-Mode signals in northern Germany. This paper has described the current state of the authors’ research and development activities at the receiver level for MF R-Mode signals. The receiver platform has been introduced, which was based on off-theshelf components and the implemented algorithms for distance estimation have been explained. Furthermore, the results of the first ranging measurements have been presented, which have shown the general suitability of the R-Mode technology as a source for maritime positioning and timing data.

3

Trajectory-based multimodal transport management for resilient transportation

Engler E., Gewies S., Banyś P., Grunewald E.

Transport Problems

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2018

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T. 13, z. 1

81--96

EN

The transport of goods and persons with two or more transport carriers (road, rail, air, inland waterway, or sea) results in multipartite transport chains whose profitability depends on the cost-effectiveness of the transport carriers involved as well as on the capability of multimodal transport management. Currently, differences with regard to the technical equipment used and infrastructural facilities available as well as administrative and public organizational structures in place are the major obstacles to comprehensive multimodal transport management within and beyond European Union borders. Though information and communication technologies (ICT) have entered into all traffic and transport systems, the levels of ICT penetration achieved in controlling, monitoring, and managing of system operation and processes are currently quite different [1-5]. One of the reasons for that is the lack of homogenous ICT standards and, as a result, the technological barriers for interconnectivity between different systems, processes, applications, and stakeholders [2]. The proposed trajectory-based concept is considered as suitable approach to perform the smart and adaptable planning, operation, and management of systems with dissimilar structures, a wide diversity of actors, and distributed responsibilities. It is therefore expected that it will be especially well suited to facilitate multimodal transport management for future Intelligent Transport Systems (ITS). Based on the “transport trajectory” formulation introduced here, it will be shown that a trajectory-based status description is generally possible for all transport-relevant components and processes. The expected benefit of the trajectory-based transport management is illustrated by means of selected transportation scenarios.

4

Long term validation of high precision RTK positioning onboard a ferry vessel using the MGBAS in the Research Port of Rostock

Ziebold R., Gewies S.

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

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2017

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Vol. 11, no. 3

433--440

EN

In order to enable port operations, which require an accuracy of about 10cm, the German Aerospace Center (DLR) operates the Maritime Ground Based Augmentation Service (MGBAS) in the Research Port of Rostock. The MGBAS reference station provides GPS dual frequency code + phase correction data, which are continuously transmitted via an ultra-high frequency (UHF) modem. Up to now the validation of the MGBAS was rather limited. Either a second shore based station was used as an artificial user, or measurement campaigns on a vessel with duration of a few hours have been conducted. In order to overcome this, we have installed three separate dual frequency antennas and receivers and a UHF modem on the Stena Line ferry vessel Mecklenburg-Vorpommern which is plying between Rostock and Trelleborg. This paper concentrates on the analysis of the highly accurate phase based positioning with a Real Time Kinematic (RTK) algorithm, using correction data received by the UHF modem onboard the vessel. We analyzed the availability and accuracy of RTK fix solutions for several days, whenever the ferry vessel was inside the service area of the MGBAS.

5

Assessment of AIS vessel position report under the aspect of data reliability

Banyś P., Noack T., Gewies S.

Annual of Navigation

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2012

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No. 19, part 1

5--16

EN

Since its introduction the Automatic Identification System (AIS) has played an important part in improving safety at sea, making bridge watchkeeping duties more comfortable and enhancing vessel traffic management ashore. However the analysis of a AIS data set describing the vessel traffic of the Baltic Sea came to conclusion, that specific parameters with relevance to navigation seemed to be defective or implausible. Essentially, it concerned the true heading (THDG) and the rate of turn (ROT) parameters. With the paper we are trying to clarify, which parameters of the AIS position report and to what extent, are affected. The detailed data analysis gives answers on how reliable the AIS data in different traffic areas is.