There has been known a private wireless system that can confirm a position of a PHS terminal with high accuracy by using a GPS and can detect the position of the PHS terminal even when base station areas overlap with each other (see Patent Document 1: Japanese Laid-open Patent Publication No. 2015-28442). In the private wireless system, the position detection by the GPS is switched to a positioning system using a PHS wireless unit when it is detected by an acceleration sensor that a movement distance of the PHS terminal exceeds a position measurable range of the base station area.
There has been known a navigation system that can quickly and appropriately switch a positioning means by displaying a desired positioning means to be selectable at user's desired timing (see Patent Document 2: Japanese Laid-open Patent Publication No. 2011-69789).
There has been known a positioning device that detects a characteristic of the light irradiated to an electronic device, identify whether the electronic device is in the indoors or outdoors, and switches to any one of a position measured by an indoor positioning unit and a position measured by an outdoor positioning unit (see Patent Document 3: Japanese Laid-open Patent Publication No. 2013-120131).