# AIS Data Vulnerability Indicated by a Spoofing Case-Study
## 2 Methodology  
A systematic literature review followed by a comprehensive, explicit, reproducible and idiosyncratic implicit method of data collection was conducted and structured following the documented guidelines [23; 24; 25]. This method consists of ten steps that can be divided into three main phases. In the first phase, planning focused on defining a review question to guide the search: \"What are the implications of AIS spoofing in the maritime domain?\" The second (review) phase identified the appropriate time frame for documents to be included from relevant research databases such as Scopus, Science Direct, Web of Science, Google Scholar and open sources. \"AIS\" and \"spoofing\" were identified as search keywords to be reviewed. After refining the selection to identify relevant documents, they were analyzed  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**AIS Class A Transponder-Ships Dynamic Conditions** & **Dual-Channel** & **Single-Channel** \\ \hline Ship at anchor or moored & 3 min & 6 min \\ SOG 0–14 knots & 10 s & 20 s \\ SOCG 0–14 knots and changing & 3.3 s & 6.6 s \\ SOCG 14–23 knots & 6 s & 12 s \\ SOCG 14–23 knots and changing course & 2 s & 4 s \\ SOCG \(>\) 23 knots & 2 s & 4 s \\ Ship static information & 6 min & 12 min \\ \hline \hline
**AIS Class B Transponder-Ships Dynamic Conditions** & **Dual-Channel** & **Single-Channel** \\ \hline SOG \textless{} 2 knots & 3 min & 6 min \\ SOCG \textgreater{} 2 knots & 30 s & 1 min \\ SOCG & & \\ Ship static information & 6 min & 12 min \\ \hline \hline \end{tabular}
\end{table}
Table 2: AIS reporting intervals [1].  
and synthesized by context, methodological approaches, and results. Our final list included 55 documents limited to AIS spoofing (28 articles, 18 peer-reviewed journal articles, and 9 reports from specialized agencies) covering the area of \"AIS spoofing\" in the period from 2019 to 2020. Some previous studies on this topic were also considered.  
In the third phase (Reporting and Dissemination), we report our findings from the literature review. The specific aspect of AIS/Global Positioning System (GPS) spoofing is corroborated by the case study analysis in Section 4 from the Faculty of Maritime Studies and Transport, University of Ljubljana, regarding a particular AIS spoofing event near Elba Island in late 2019.  
As part of the research, AIS data were first obtained through cooperation with the Slovenian Maritime Administration, which is stored at MARES regional data exchange program. Additional AIS day data were subsequently obtained from the Italian Coastguard. These data were used to analyze the strength of signals received at the AIS BS on the island of Elba. The French agency maintaining the AIS system and the commercial providers MarineTraffic and VesselFinder were also contacted. An investigation into the consequences of this event followed; seven vessels were found to be in a spoofing cloud, a letter was sent to those in charge of the International Safety Management code (ISM) implementation to enquire about the possible consequences for the safety of shipping. Afterward, the archive data were streamed again using the application AIS Network Data Client and played in two different VTS applications Navi-Harbor (Wartsila) and Pelagus (Elman). A navigation scenario was then configured in the affected area. The AIS spoofing data were displayed on ECDIS and RADAR applications via the ship tracking simulator Navi Trainer Pro (Wartsila). An analysis of the collected data follows. Finally, using the European Marine Observation and Data Network (EMODnet) method [26], a traffic density map (TDM) was created by using ship positioning data from terrestrial and S-AIS data sources, maritime infrastructure, and the SafeSeaNet Ecosystem Graphical Interface (SEG) application.