Ranging Accuracy of MSAS Signal

Abstract

SBAS (Satellite-Based Augmentation System) is the standard system which augments GNSS using geostationary satellites. The structure of SBAS signal is same with GPS and this means the SBAS satellites have capability to work as additional ranging satellites like GPS. Japanese SBAS called MSAS once provided messages for this ranging function, but nowadays does not. Recently MSAS has updated its geostationary satellite in April 2020, and this likely means the ranging accuracy also has some difference due to change in the signal generation payload if MSAS provides the ranging function again. The authors have evaluated the ranging accuracy of the MSAS signal before and after the replacement of its geostationary satellite and confirm an improvement over the past to the same level with GPS.