# The Impact of Space-Based AIS Antenna Orientation on In-Orbit AIS Detection Performance
## 4 Conclusions  
Within this paper, the analysis on the impact of varying the orientation of monopole \(\lambda\)/4 AIS antenna on its message reception performance has been presented. The analysis has been carried out by involving AIS datasets collected under 45\({}^{\circ}\)-maneuvered and 90\({}^{\circ}\)-maneuvered flight configuration applied on LAPAN-A2, an equatorial orbiting microsatellite. In this case, the 45\({}^{\circ}\)-maneuvered and 90\({}^{\circ}\)-maneuvered, respectively, refer to the satellite attitude configuration in which the antenna is oriented 45 and 90\({}^{\circ}\) towards the satellite flight direction. Based on the analysis over those datasets, it is confirmed that the highest message reception performance can be achieved by orienting the monopole \(\lambda\)/4 antenna 45\({}^{\circ}\) toward the flight direction. This antenna orientation gives a significant increase in overall AIS messages reception, including class A and class B type ships. From this finding, it is recommended for a small satellite or other satellite type carrying AIS payload to mount its monopole antenna orientation 45\({}^{\circ}\) towards its orbital flight direction.  
Further study may be done by using other orientation angles or a combination of another type of antenna and different frequency. It also might be interesting to observe the performance of dual-polarization antennas for space-based AIS.  
This research contributed with the following contribution; conceptualization, W.H.; methodology; W.H.; software, K., W.H.; data curation; K., W.H.; validation, W.H., M.M., and U.R.; formal analysis, W.H., M.M., K., U.R.; visualization, W.H., K., and M.M.; supervision U.R.; writing--original draft, W.H., K.; writing--review and editing, W.H., K., M.M., and U.R.  
This research received no external funding.  
We would like to acknowledge the additional contribution from Satellite Operation Team in Satellite Technology Center, National Institute of Aeronautics & Space (LAPAN) Indonesia and also RF team that support this research.  
The authors declare no conflict of interest.  
Figure 17: Class B sample of ship tracking detection.  
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