Positioning system and positioning method

A positioning system for estimating the position of a receiver that has a GPS positioning function, a base station positioning function, and a wireless communication function, the system comprising:

• GPS reception means for receiving signals from a GPS satellite;
• position estimation means for estimating the position of a receiver from a received GPS signal;
• reception state information acquisition means for acquiring reception state information indicating the reception state of a radio wave produced by the wireless communication function of the receiver;
• position estimation means for estimating the position of the receiver on the basis of the reception state information acquired by the reception state information acquisition means;
• end decision means for deciding whether or not to end the position estimation by the position estimation means on the basis of a specific end condition, and, if it is decided not to end, causing the position estimation means to estimate the position of the receiver on the basis of new reception state information acquired by the reception state information acquisition means at a different timing from that of the reception state information used by the position estimation means to estimate the position;
• indoor/outdoor determination means for determining whether the receiver is indoors or outdoors on the basis of the reception state information acquired by the reception state information acquisition means;
• and
• end condition determination means for determining the specific end condition on the basis of a result of determination by the indoor/outdoor determination means.