Geometric Sensitivity Index for the GNSS Using Inner Products of Line of Sight Vectors

• Published in: International journal of aeronautical and space sciences Vol. 16; no. 3; pp. 437 - 444
• Main Authors: Won, Dae Hee, Ahn, Jongsun, Sung, Sangkyung, Lee, Chulsoo, Bu, Sungchun, Jang, Jeagyu, Lee, Young Jae
• Format: Journal Article
• Language: English
• Published: 한국항공우주학회 01.09.2015
• Subjects: 항공우주공학; Inner Product; Sensitivity; Performance Index; GNSS; Line of Sight Vector
• ISSN: 2093-274X; 2093-2480
• DOI: 10.5139/IJASS.2015.16.3.437

Satellite selection and exclusion techniques have been applied to the global navigation satellite system (GNSS) with the aim of achieving a balance between navigational performance and computational efficiency. Conventional approaches to satellite selection based on the best dilution of precision (DOP) are excessively computational and complicated. This paper proposes a new method that applies a geometric sensitivity index of individual GNSS satellites. The sensitivity index is derived using the inner product of the line of sight (LOS) vector of each satellite. First, the LOS vector is computed, which accounts for the geometry between the satellite and user positions. Second, the inner product of each pair of LOS vectors is calculated, which indicates the proximities of the satellites to one another. The proximity can be determined according to the sensitivity of each satellite. A post-processing test was conducted to verify the reliability of the proposed method. The proposed index and the results of a conventional approach that measures the dilution of precision (DOP) were compared. The test results demonstrate that the proposed index produces results that are within 96% of those of the conventional approach and reduces the computational burden. This index can be utilized to estimate the sensitivity of individual satellites, obtaining a navigation solution. Therefore, the proposed index applies to satellite selection and exclusion as well as to the sensitivity analyses of multiple GNSS applications. KCI Citation Count: 0