GPSD, How to get the last known location?

if GPS-module disconnected, or if GPS antenna gets moved into building, I wan't to know the last available location. I tried to log location every 10 or so seconds with systemd-timers; However, exactly when log-file is updating every 10 sec, there is an instance cat -ing log-file returns empty. This needs to be robust as possible, since inexperienced user will be operating the system. Are there anything tools within GPSD tools that provide this?