On the receiver side, yeah. On the satellite side, I had vague memories they were weird when I wrote that. From some quick googling I think they are doing a tr

On the receiver side, yeah. On the satellite side, I had vague memories they were weird when I wrote that. From some quick googling I think they are doing a trick with clock synchronization from ground stations to avoid needing an atomic clock in space, since over Japan and Australia they will always have LOS to a ground-station (which they can use in place of the atomic clock as the master time source for each satellite)[1]. At least, that's what the 2008 Ph.D thesis "Remote Synchronization Method for the Quasi-Zenith Satellite System: study of a novel satellite timekeeping system which does not require on-board atomic clocks"[2] suggests that they were doing. That was published before the QZSS system actually flew, so I still am not sure if they actually went that way or stuck with the conventional atomic-clocks-in-space approach. So maybe they are unique in not needing so much hardware in space, perhaps? 1: GPS, designed to deal with at least the opening stages of nuclear war, had as a design goal the ability to operate without ground stations at least for a while, and there are large swathes of the world that don't have suitable ground stations, so they had to go with the atomic-clocks-in-space route to provide global coverage. By focusing on just a small area and ignoring the 'must operate for several days during a nuclear war' case, QZSS maybe could get away with something cheaper. 2: https://unsworks.unsw.edu.au/server/api/core/bitstreams/93862270-6598-4a9f-be97-db54ad62ef12/content https://unsworks.unsw.edu.au/server/api/core/bitstreams/9386...