# Decentralized Documentation of Maritime Traffic Incidents to Support Conflict Resolution
## 5 Application and Evaluation
### Evaluation Scenario  
During mooring maneuvers, collisions between vessels and the quay walls occur regularly. Often, minor damages remain undetected at first and are only noticed by the port operator after some time. A subsequent clarification of which vessel caused the damage is no longer possible so that the port remains on the incurred costs. To prevent this, port operators are interested in documenting the berthing maneuvers of vessels in a trustworthy way. To evaluate the presented approach for the decentralized documentation of maritime incidents, we applied our system to a real-world problem of port operators and assessed it with respect to its functionality and performance. For this purpose, the system was embedded in the _SmartKai_ testbed in Cuxhaven, Germany (c.f. Figure 5(a)). The _SmartKai_ testbed was set up for the development of a port-side assistance system to support pilots and captains during the berthing of vessels. This is realized by measuring the distance of a vessel to the quay wall using LiDAR sensors and making it available to the stakeholders in real-time. In contrast to AIS, the measurements are not limited to a single reference point but cover the entire contour of a vessel and are available to the stakeholders at a much higher frequency (5 Hz). In total, the _SmartKai_ testbed provides 8 LiDAR sensors, radar, and AIS data over the entire port area, and other environmental data such as tidal, weather, and visibility information. Due to the high number of available sensors and the realistic environmental conditions such as the used hardware and network, the testbed is ideally suited to evaluate the presented approach properly. The functionality of the presented approach is demonstrated by a mooring maneuver of the vessel _Steubenhoeft_ at the quay wall in the harbor of Cuxhaven. The _Steubenhoeft_ is a dredger that is 40 m long and 10 m wide (c.f. Figure 5(b)). In principle, the proposed approach could also be used to document any other traffic situation. Within the evaluation mooring scenario, a total of three participants take part (c.f. Figure 7):  
1. The Port Operator who operates the port is interested in ensuring that the quay wall of the port is not damaged and has installed 8 LiDAR sensors at the quay wall with an update frequency of 5 Hz. The sensors' measurements are synchronized so that they can be collected and signed together. Furthermore, the Port Operator trusts TSA1 and TSA2 but does not rely on any other external entity. 2. The Vessel Traffic Service Operator knows the Port Operator and supports the berthing documentation by providing valuable environmental data about the port area. The VTS operator collects AIS, visibility, tidal, and wind data. The AIS data is received several times per second from surrounding vessels at irregular intervals. The installed wind sensors update with a frequency of 10 Hz, and the visibility sensor every minute. In contrast, the tidal information is retrieved only once per hour.The VTS Operator mainly trusts TSA3. If it is not possible to agree directly on the first priority, the VTS Operator also trusts the TSAs of its trusted entity--the BSH. Figure 6: (a) LiDAR sensor at the quay wall in Cuxhaven, Germany, to measure the distance between the quay wall and vessels (part of the SmartKai infrastructure) (b) Dredger vessel _Steubenhoeft_ with which the mooring maneuver that has to be documented was performed. 3. The Berthing Vessel is the vessel that wants to moor in the port. The Berthing Vessel stores its received AIS messages and own GPS positions. The GPS data is encoded in the NMEA0183 format and is updated with 1 Hz. The vessel relies primarily on TSA4 and TSA5. However, the vessel is willing to expand its list in two additional iterations: Once by the TSAs of its trusted entities--the DLR and the IALA and another time by the TSAs of the trusted entities of the DLR and IALA. The hardware and software of the three participants is deployed on three separate machines.