For a variety of different applications in public institutions and companies
it might become necessary to use Automatic Identification System Data. Various online offers allow an easy access to these data. However, for its usage a detailed analysis of the legal grounds is necessary in order to derive sound statements.
Introduction
The joint research project of the University of Rostock and the University of Applied Sciences Wismar aims[ds_preview] at developing a method that helps to calculate the capacity of straits on international sea routes. The depth of the navigable channel is often sufficient for the maritime traffic. However, geological reasons as well as multilateral agreements which regulate restrictions of fairways might narrow the available route significantly. In analogy to road traffic, the maximum capacity of the observed area (Kadet Trench) is calculated on the occurrence of timely similar phenomenons of traffic jam. For this purpose the relation between speed and distance behaviour of traffic participants is analysed. Furthermore, unbiased basis data had to be extracted based on Automatic Identification System (AIS) data from 2010 to 2012. With the help of these data the capacity of the Kadet Trench may be calculated.
Basics of the AIS
The AIS is a broadcast radio process which is based on the Recommendation ITU-R M.1371 standard and which transfers coded information. The transmitted information can be categorized as static ship data (e. g. MMSI, vessel name, vessel type, vessel size), dynamic travel data (e. g. ship’s position, course, speed, rate of turn, heading) and specific travel data (e.g. class of hazardous material, destination, ETA, people on board). The standard that was confirmed by the IMO on 6 December2000 as well as by the SOLAS regulation for AIS aims at a land side traffic guidance through the respective littoral state – including detailed information on the ship or cargo – and therefore contributes to a collision avoidance between vessels for an increased safety on sea.
The AIS has been in use since the year 2000. Since 1 January 2001, all newly built ships with equipment falling under the carriage requirement regulations have to be equipped with AIS. Vessels already in service were granted a transition period. Since 1 January 2004 all merchant vessels on international routes with more than 300 gt have been obliged to carry AIS equipment. Since 1 July 2008 the regulation applies to all merchant vessels on national routes with more than 500 gt and vessels with more than 50 passengers or a length of more than 50m.
Functions of WSD North
According to the Federal Maritime Responsibilities Act (»Seeaufgabengesetz«) the German Waterways and Shipping Directorate North (WSD-N) has to guarantee amongst others a smooth flow of traffic in German territories. In order to fulfil the requirements of §9 of the Federal Maritime Responsibilities Act, the German Waterways and Shipping Directorate North operates AIS land stations and traffic control centres whose positions are outlined in Figure 1.
Through its infrastructure, the WSD-N receives the transmitted AIS data, concentrates these in a data base and makes them accessible to authorised personnel. The overlapping of covered areas avoids the loss of data flow in case of interruptions or interferences of the receiving station. Traffic control centres – as regular data consumers – are equipped with a comprehensive AIS-supported visual map.
Consistency of the data base
According to the Federal Maritime Responsibilities Act, the WSD-N has fully taken over the backup and processing of data and has been the central contact institution for requesting access to AIS data of the German territories since 1 January 2010. Findings of the research project have shown, however, that due to technical reasons, data has only been available from 1 March 2010 onwards. A closer diagnosis of the consistency of the data within the claimed time frame from 1 March 2010 to 21 December 2012 in the sea area of the Kadet Trench (coordinates 054°38’ North/012°28’ East and 054°19’ North/011°53’ East) found a number of time gaps. These time gaps range from 5–60 seconds and have been detected in ca. 2,000 positions of the data. The time gaps do not have a significant effect on the approximation of the ship’s course and the later evaluation of the capacity of the sea route. Bigger gaps that range from 36–60 seconds over a number of days have a more significant effect and usually occur due to technical retrofittings or system failures of the archive. With regard to the claimed time frame a very good temporal consistency of more than 99% can be reported.
Privacy Act and AIS data
According to Paragraph 1 of the Freedom of Information Act, all natural individuals have the right to access official data. The right to access AIS data is based on this act. However, it has to be clarified if AIS data is personal data and therefore falls under the German Federal Data Protection Act (»Bundesdatenschutzgesetz«) which applies to all natural individuals. Until the moment of application, it remained unclear if the historical AIS data can be defined as personal data.
In order to clarify the state of AIS data according to the German Federal Data Protection Act, a request was sent to the Data Protection Supervisor of Mecklenburg-Western Pomerania and to the Data Protection Supervisor of the University of Applied Sciences Wismar. Against our premier estimations, the protection of data under the Privacy Act according to the Telecommunications Act (§ 88, 89, 91) as well as the Data Protection Act of the federal state of Mecklenburg-Western Pomerania (§34) is to be applied. As long as personal data is being anonymised, their usage for research purposes does not contradict these acts. In rare cases, non-anonymised data may only be used for research purposes with the consent of the person concerned.
Due to this legal perspective, it can be assumed that historical AIS data which can be accessed through the website Marine Traffic contradicts German legal regulations. Therefore, the usage of data of other sources other than the WSD-N has to be questioned for users in Germany.
Legal position of the case study
At the WSD-N, AIS data can generally not be accessed in a non-anonymised format. The application needs to contain a valid reason for the necessity and will be put under legal examination. Our research project applied for non-anonymised data and the valid reasons were proved. The following step included the balancing of the individual case between the reasons of access and the right of every person on information-related self-determination. For our research project it was decided that data protection has priority over research interest and the project could also be completed successfully with anonymised data. This applies also to the freedom of science, research and teaching regulated in basic law (§5).
In order to guarantee data protection in the production of anonymised data, the ship’s name is being removed and substituted by the MMSI. For the consistency of data and for evaluation purposes, the MMSI for the first data record of ships is being fixed arbitrarily to 10,000,000 and is being incremented by one with every further ship. This procedure allows to assign each data record a single traffic participant without identifying them directly.
Useful modus operandi for the application process
For the application for AIS data, a form that is being provided by the WSD-N needs to be filled out. Next to the contact data, the purpose for the usage needs to be explained plausibly and in detail. The purpose is being examined according to formal reasons of §7 section 1 of the Information Act. In case of applying for non-anonymised data, the applicant has to explain in detail the necessity of accessing these data records.
For the definition of sea routes the coordinates have to be listed in WGS84 format with longitude and latitude (geodetic reference system). It is highly recommended to opt for a geometrical structure such as rectangle defined through the corner points.
Depending on the workload of the WSD-N it takes four to twelve weeks until the applicant receives a DVD data medium which stores monthly AIS data in data bank format (*.db). The data records are stored in chronological order according to the processing dates of the IT infrastructure. Each data record is preceded by two biunique time stamps. The original AIS data is stored in NMEW 0183 format. The currently valid AIS standard only allows listing the time of the position specification of the receiver in relation to the actual minute after GPS in the dimension of 0–59 seconds. Sticking to this standard would lead to severe difficulties in interpreting the data records with the correct time. The additional time stamp allows for a correct mapping including time gaps of 60 seconds. Due to the high AIS net coverage, the same signal differs only in radio time and may be received by two different infrastructure institutions. For these reasons the same data records may appear numerous times in the data base. The costs for the application in our illustrated case amount to roughly 200€ for ca. 300 mill. AIS data records. The visualisation of these data for the month of March 2010 is demonstrated in Figure 2.
Conclusion
Against a fee, companies and research institutions can apply at the WSD-N for AIS data that cover sea areas for a specific amount of time. Despite specific data protection regulations, the data records can be used in their original form or in an anonymised format in individual cases. Offers by third-party services are not relevant. Due to the above mentioned legal grounds the usage of online data is questionable.
Authors:
Dipl.-Ing. Carsten Hilgenfeld, M.Sc.
carsten.hilgenfeld@hs-wismar.de
Dipl.-Ing. Frank Hartmann, both at Hochschule Wismar –
University of Applied Sciences, Department of Maritime Studies
Prof. Dr.-Ing. Manfred Ahn, Hochschule Wismar –
University of Applied Sciences, Department of Civil Engineering
Carsten Hilgenfeld, Frank Hartmann, Manfred Ahn
