The Role of Antennas on GNSS Pseudorange and Multipath Errors and Their Impact on DFMC Multipath Models for Avionics

Kurzfassung

Current satellite navigation systems are providing more and more dual frequency capabilities, enabling an improved navigation accuracy and reduction of residual errors (e.g. from ionosphere)[1,2]. Recently, the aviation community has started an effort to achieve new standardized minimum operational performance specifications (MOPS) for GNSS equipment, in order to allow for use of dual frequency multi constellation (DFMC) systems in the future, with clear benefits in terms of obtainable navigation performance. In such conditions, residual errors introduced by the user GNSS antenna become more and more relevant and need to be properly identified and bounded, both in the antenna specifications and, in the models for aircraft multipath. The present work tackles this problem and shows the results of an activity aiming at developing the airborne multipath models for L1/E1, L5/E5a and for their ionospheric-free (Ifree) combination. The paper shows a detailed investigation of the physical rationale of such errors.