Effect of ground station geometric distribution on wide area multilateration positioning performance

• Main Authors: JasonGuo, 郭家昇
• Other Authors: Shau-Shiun Jan
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/06419113489652906462

碩士 === 國立成功大學 === 民航研究所 === 103 === Global navigation satellite system (GNSS) is essential to aviation communication, navigation, surveillance, and air traffic management. A continuous accurate positioning service allows a GNSS-supported surveillance system to keep up with the growing requirements of civil aviation. However, many studies have shown that GNSS signals are susceptible to interference. To continue accurate positioning service in the case of GNSS failure, various alternative positioning, navigation, and timing (APNT) systems have been proposed. The objectives of APNT systems are to provide navigation and surveillance services to ensure flight safety when GNSS fails. In the first part of this thesis, the wide area multilateration (WAM) mechanism for APNT systems is developed using commercial off-the-shelf components, and a city-size multilateration experiment is carried out in the proximity of Tainan, Taiwan. Using the four ground reference stations surrounding Tainan, the differential time of arrival positioning algorithm is employed to calculate the positions of aircraft passing above Tainan. The positioning results show positive positioning result with positioning error around 100 meters horizontally. However, this experiment also showed the mechanism’s limitation on the positioning due to the geometry of stations. In the second part of this thesis, to overcome the geometry limitation, a viable concept is developed based on a multi-measurement positioning algorithm. A simulation is conducted to validate the proposed concept. In comparison to the original WAM based APNT, the results showed that the positioning service coverage is increased about 10% using multi-measurement positioning algorithm.