碩士 / 國立臺灣大學 / 電機工程學研究所 / 88 / GNSS (Global Navigation Satellites System) is the general meaning of the satellites-based navigation system. The available two systems include GPS (Global Positioning System) of the United States and GLONASS (Global Navigation Satellites System) of the Russia.
GPS is a global, all-weather and twenty-four-hours, precise three-dimensional navigation system. It is developed by DOD of the United States. WGS-84 coordinate and UTC-USNO time system are adopted in GPS. The signal transmitted by the techniques of CDMA (Code Division Modulation Access). The location of the satellite is figured out by the Keplerian orbital equation. GLONASS likes GPS. It is developed by the Russia for military purpose. Those satellites are distributed in high latitude areas. The PZ-90 coordinate and UTC-SU time system are adopted in GLONASS. The signal transmitted by the techniques of FDMA (Frequency Division Modulation Access). The numerical iterative algorithm in rectangular coordinate is used to calculate the positions of satellites.
Both GPS and GLONASS used the principle of triangulation. To combine them, we transfer the coordination of GLONASS satellites from PZ-90 to WGS-84. Next, the difference of time and frequency between the two systems should be carefully treaded. The time-alignment problem between two receivers is solved by appropriate receiver operation command. To increase the accuracy of the position of GLONASS satellite, a suitable time step for iteration is selected. Also, the previous data of the satellite positions can save computation time.
We successfully combined the GPS and GLONASS for navigation. In static experiments, we completed the single receiver positioning (SA on and SA off), and the double receivers positioning. The algorithms are associated to the observables of code, carrier phase and carrier smoothed code. In dynamic experiments, the vehicles used are handcart and automatic course-tracking vehicles. The observables used are carrier phases. The two receivers’ configuration is applied to handcart. We can get the vehicle trajectory. The three receivers’ configuration is applied to automatic course-tracking vehicles. We can get the vehicle trajectory and heading angles.
According to the data from the above experiments, we confirm that GPS and GLONASS integrated system is more precise than that of GPS or GLONASS alone. Furthermore, this integration can increase the number of satellites in view. Satellites from both systems will cover the high, middle, and low latitude areas. The experience of the GPS and GLONASS integration will help us to integrate some other satellite navigation system in the future.
| Identifer | oai:union.ndltd.org:TW/088NTU00442056 |
| Date | January 2000 |
| Creators | 蔡宜學 |
| Contributors | , 張帆人, 王立昇 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 133 |
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