Patent ID: 6424297
Filing Date: 2002-07-23
Classification: G01S

Abstract:
A moving body position detection method for detecting a current position of a mobile station capable of movement and also capable of data communication between itself and at least fixed stations using radio waves, comprising the steps of:storing precise positions of the fixed stations in advance in the mobile station; storing precise positions of one of the fixed stations and a radio wave clock base station in advance in the one of the fixed stations; synchronizing a clock of each fixed station with clocks of GPS satellites based on time information contained in radio waves sent by the GPS satellites, for keeping a common time respectively in the fixed stations, or alternatively, synchronizing the clock of each fixed station with a clock of the radio wave clock base station by: calculating the radio wave propagation time between each fixed station and the radio wave clock base station based on the positions of each fixed station and the radio wave clock base station and the speed of light, receiving the radio waves containing the time information sent by the radio wave clock base station, subtracting the radio wave propagation time from the time information of the radio wave clock base station, and setting the subtraction result in the clock of each fixed station; wherein the fixed stations send radio waves containing time information of the clocks therein, the mobile station receives the radio waves sent by the fixed stations and calculates distances between the mobile station and the fixed stations by determining differences between a clock provided in the mobile station and the time information contained in the radio waves sent by the fixed stations; and the mobile station calculates the position of the mobile station from the calculated distances and from the precise positions of the fixed stations that were stored in advance.