Patent ID: 7986264
Filing Date: 2011-07-26
Classification: G01S

Abstract:
1. A positioning system estimating the position of a receiver, comprising: a velocity-vector calculating unit that calculates velocity vectors of a plurality of GPS (Global Positioning System) satellites on the basis of signals sent from the GPS satellites and received by the receiver, wherein the plurality of velocity vectors indicate a relative movement of the GPS satellites with respect to each other; a signal-transmitter selecting unit that generates a combination of velocity vectors from the velocity vectors calculated by the velocity-vector calculating unit and selects GPS satellites from the plurality of GPS satellites on the basis of the generated combination of velocity vectors; a position calculating unit that calculates positions of the receiver at a plurality of times, the times being signal transmission times, on the basis of signals transmitted from the GPS satellites selected by the signal-transmitter selecting unit and received by the receiver; a transmission-time setting unit that evaluates the accuracy of the positions of the receiver calculated by the position calculating unit and sets one time selected from the plurality of times corresponding to the plurality of positions as a transmission time; and an estimated-position setting unit that sets the position of the receiver corresponding to the transmission time set by the transmission-time setting unit as an estimated position of the receiver.