RESSOX experiments using a low-elevation-angle geostationary satellite

We have been conducting research on the remote synchronization system for the onboard crystal oscillator (RESSOX), which does not require onboard atomic clocks, for the QZSS since 2003. Since a QZSS does not yet exist, we have been conducting synchronization experiments using a current geostationary satellite to confirm that RESSOX is an excellent system for timing synchronization. To examine the applicability of RESSOX under severe conditions of tropospheric delay, Intelsat-4 was selected. Intelsat-4 is located at an elevation angle of 7.9 degrees as viewed from our institute. The experimental setup, the results of experiments, and some discussions will be presented.