Design and Implementation of a Buoy Positioning and Monitoring System Using Differential GNSS and LoRaWAN
When vessels at sea currently install sea marks, such as floating buoys, they use their own Global Navigation Satellite Systems (GNSS) receivers to acquire a position and use that as an estimate for the buoys’ position, but the buoys are typically installed from the rear of the vessel while the GNSS...
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| Format: | Thesis |
| Language: | English |
| Published: |
2022
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| Online Access: | http://hdl.handle.net/1946/42867 |
| Summary: | When vessels at sea currently install sea marks, such as floating buoys, they use their own Global Navigation Satellite Systems (GNSS) receivers to acquire a position and use that as an estimate for the buoys’ position, but the buoys are typically installed from the rear of the vessel while the GNSS receiver is closer to the middle of the vessel. These vessels are quite large and there are several meters between the GNSS receiver and the where the buoy is actually installed. Errors in the GNSS signals, which are mainly caused by Earth’s ionosphere, further add to the inaccuracy of the buoys’ position. The inaccuracy caused by the errors can be drastically mitigated by using GNSS correction data. The purpose of this thesis is to develop a system that includes a device that could be placed on a buoy in order to acquire a highly accurate position using GNSS and real-time GNSS correction data while also using low amounts of power. To achieve this a LoRa Wide Area Network (LoRaWAN) was set up which includes a LoRaWAN gateway that transmits corrections to the buoy device which uses them to acquire a position with a positioning error of less than a meter. The corrections are provided by a Continuously Operating Refer- ence Station (CORS) network operating in Iceland called IceCORS which streams the corrections over the internet. The corrections are fetched by a Raspberry Pi computer which relays them to the LoRaWAN gateway via Ethernet. The buoy device is an ESP32-based microcontroller equipped with a LoRa transceiver module and a GNSS receiver. The Raspberry Pi and gateway can be placed on the vessel installing the buoy (assuming the vessel has Internet connectivity) or on shore with a good view over the areas where buoys would be installed as LoRa communication requires a line of sight when communicating over distances of multiple kilometers. In-field testing revealed that the corrections transmitted via LoRa provided a signif- icant increase in the position accuracy and well within 1 m. They also revealed that ... |
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