Jongsun Ahn and YoungJae Lee/ DaeHee Won/ Hyang-Sig Jun and Chanhong Yeom/Sangkyung Sung and Jeong-Oog Lee
International Journal of Aeronautical and Space Sicences, vol. 16, no. 1, pp.89-101, 2015

Abstract : To satisfy civil aviation requirements using the Global Navigation Satellite System (GNSS), it is important to guarantee system integrity. In this work, we propose a fault detection algorithm for GNSS ephemeris anomalies. The basic principle concerns baseline length estimation with GNSS measurements (pseudorange, broadcasted ephemerides). The estimated baseline length is subtracted from the true baseline length, computed using the exact surveyed ground antenna positions. If this subtracted value differs by more than a given threshold, this indicates that an ephemeris anomaly has been detected. This algorithm is suitable for detecting Type A ephemeris failure, and more advantageous for use with multiple stations with various long baseline vectors. The principles of the algorithm, sensitivity analysis, minimum detectable error (MDE), and protection level derivation are described and we verify the sensitivity analysis and algorithm availability based on real GPS data in Korea. Consequently, this algorithm is appropriate for GNSS regional implementation.

Keyword : GNSS, integrity, ephemeris failure detection, baseline length estimation