Satelitní komunikace prostřednictvím technologie Lora

Abstract

This diploma thesis deals with the design and implementation of a receiving system for the reception of satellite LoRa (Long Range) transmissions from low Earth orbit (LEO) satellites within the TinyGS community network. The aim of the thesis is to design a technical solution enabling the comparison of the influence of different antenna configurations on reception quality and reception success, while also creating a system for automatic satellite tracking based on TLE (Two-Line Element) data.

The theoretical part summarizes the principles of satellite communication, radio channel degradation, the properties of LoRa technology in the satellite environment, and an overview of available communication modules applicable to satellite communication. The practical part describes the design of three ground stations based on LILYGO LoRa32 modules, the selection of the antenna system, the construction and tuning of a helical antenna for the 435 MHz band, and the selection of a suitable rotator for automatic satellite tracking.

The solution also includes a custom software layer running on the Raspberry Pi platform, which processes MQTT (Message Queuing Telemetry Transport) data from the TinyGS network, assigns TLE models, calculates the azimuth and elevation of satellites, controls the antenna mount, and stores operational as well as quality-related data in a database. The experimental evaluation of a 48-hour measurement showed that the directional helical antenna achieved the best RSSI (Received Signal Strength Indicator) and SNR (Signal-to-Noise Ratio) values, while the linear whip antenna achieved a higher frame count and a higher probability of receiving at least one frame during a pass. The result of the thesis is a functional platform for receiving satellite LoRa transmissions, demonstrating that practical reception success depends not only on antenna gain, but also on operational robustness, polarization matching, and antenna elevation coverage.