Summary: | 碩士 === 國立成功大學 === 電機工程學系碩博士班 === 91 === Ground-based pseudolites can transmit GPS-liked signals and augment GPS constellations to enhance the accuracy, integrity, and availability. Pseudolites can overcome the limitation due to signal obstruction. Also, as most pseudolites are located at low elevation, the geometric dilution of precision is improved in a combined GPS/Pseudolites positioning system. Other applications of pseudolites are local-area augmentation system, indoor navigation, and so on. The thesis designs, implements, and tests an indigenous dual-frequency GPS pseudolite which consists of a FPGA encoder, RF circuit, and associated software. Furthermore, the pseudolite is also equipped with an L2C encoder to anticipate the modernization of GPS. The signal characteristics and clock properties are then analyzed in laboratory and field test.
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