The Multi-functional Satellite Augmentation System (MSAS) is a Japanese Satellite Based Augmentation System (SBAS) [1] which provides Differential GPS (DGPS) corrections and is designed to supplement GPS by reporting and monitoring the reliability and accuracy of GPS signals in real time. MSAS consists of two satellites, (MTSAT-1R at 140E longitude and MTSAT-2 at 145E longitude), four Ground Monitor Stations (GMS), two Master Control Stations (MCS),…