2010年將有一套完整的CNS/ATM系統產生，其中在導航方面以區域性增強系統為主要的機場導航設施，以地面虛擬衛星彌補傳統GPS衛星在導航上的不足。為滿足區域性增強系統性能需求中的精確度，本研究以載波相位平滑化法及差分修正法提昇定位精確度。
本研究主要的目標為使用載波相位修正法，抑制衛星的雜訊至公分等級，並設計實驗，考慮加入虛擬衛星、GDOP值與衛星顆數等變因，解算出公分等級的精度。
結果顯示，本研究中所使用方法搭配虛擬衛星，在平面上或垂直高程上皆有公分等級的定位精度。飛行測試則因虛擬衛星發生遮蔽，垂直高程精度約為1.36公尺。

After 2010, there will be a complete CNS/ATM system available. In the subsystem of Navigation, the LAAS will become the primary GPS navigation aid in airports. It is intended to compensate the GPS satellite geometric distribution with ground pseudolite facility. To analyze the LAAS accuracy in order to understand its performance, this study adopts the carrier phase smoothing method and DGPS technique to improve the GPS positioning.

One of the goals in this research is the application of phase-smoothed method in reducing the measurement noise to achieve the centimeter accuracy. The other goal is to use the pseudolite to improve the GDOP value and hence the satellite distribution. The results show that the adopted smoothed method provides centimeter accuracy in both horizontal and vertical directions while non-smoothed results are in meter level. Two flight experiments were conducted to impose a real environmental test. Although the pseudolite signal was blocked by nearby hill several times, the vertical solutions are good in meter level.

【1】Braff, “Description of the FAA’s Local Area Augmentation System (LAAS)”, Journal of the Institute of Navigation, Vol. 44, No. 4, Winter 1997-1998.
【2】H. S. Cobb, “GPS Pseodolites: Theory, Design, and Applications”, Ph.D. Thesis of the Dept. of Aeronautics and Astronautics, Stanford University, September 1997.
【3】D. Somerville, “LAAS Testing at the University of Oklahoma”, FAA SatNav, December 2001.
【4】莊智清, “雙頻虛擬衛星發射器之建立”, 第五屆GPS衛星科技研討會,November 2002.
【5】莊智清, “虛擬衛星擴增式導航與定位之研究”, 第五屆GPS衛星科技研討會, November 2002.
【6】羅正方, “虛擬衛星應用於GPS-RTK測量之驗證”, 第五屆GPS衛星科技研討會, November 2002.
【7】T. G. Morley, “Augmentation of GPS with Pseudolites in a Marine Environment”, M.S. Thesis of the Dept. of Geomatics Engineering, The University of Calgary, Calgary, Alberta, Canada, May 1997.
【8】http://www.novatel.com/Documents/Papers/Dlseries.pdf