Development of a Satellite Communication System for the Submarines of the Royal Netherlands Navy

Abstract

The Brik-II satellite is a Nano-Satellite which has the main objective to be a technology demonstrator and prove the use of self owned military satellites. One of the payloads onboard the Brik-II satellite is called the Store and Forward payload. It has the capability to Store and Forward messages from and to different military assets. To demonstrate this capability it has been purposed to design and install a communication system onboard the Royal Netherlands Navy submarines enabling communication with Brik-II. Subsequently, this would be a good way to demonstrate the performance and operational relevance of such system.
The first step was to identify the problem that should be solved. The main objective of this MSc thesis was to design, manufacture and test an operationally deployable communication system for the submarines operated by the Royal Netherlands Navy. Based on the main objective and consultation with the Navy the requirements of the system were compiled. From the requirements it was concluded that there are a number of similarities between the Remote Radio Station (RRS) and the submarine communication system. However, the antenna system installed on the RRS cannot meet the size requirements. Therefore a new antenna systems had to be design that would comply with the requirements. This has been the main focus of this MSc thesis.
To find the optimal design for the antenna, a simulation tool for the communication between the submarine and Brik-II was developed. In the model different antennas were tested to identify the optimal design. The type of antenna used in the optimisation is a helical antenna. Once the optimal design was identified it was manufactured used the 3D printing facilities at the 982 Squadron in Dongen. Hereafter, measurements were conducted to verify that the radiation pattern of the antenna corresponds with the predicted radiation pattern. The similarities in shape between the predicted and measured pattern were evident. However, the measured gain of the antenna was lower than the predicted gain. To meet the requirements the losses will have to be mitigated. Multiple solutions were purposed to reduce the losses. A communication test between the antenna and the satellite could not be conducted due to technical difficulties during testing.
Part of the main objective was to develop an operationally deployable system. This first prototype developed in this MSc thesis provides a basis for further iteration. The current design imposes two constraints on the deployability. First the antenna gain losses have to be mitigated since the lower gain results in less than required data throughput. The losses can be reduced by implementing the proposed solutions. Second, the choice of a helical antenna with an omnidirectional radiation pattern results in an increased chance of detection by possible adversaries. This functional constraint cannot be remedied due to the size requirements. In conclusion, the antenna design proposed in this thesis gives a basis for a system that can provide added value to the operations of the submarine.