| 摘要 |
PROBLEM TO BE SOLVED: To directly judge whether a received GPS signal is a multipass or not by observing the signal, thereby eliminating the influence of the multipass from the positioning solution of GPS. SOLUTION: The estimated Doppler shift amountΔfr of a received GPS signal is calculated based on the position and velocity victor (ud) of an own vehicle calculated by a dead reckoning function according to the definition, represented byΔfr=-fT. (v-ud).a/c} (wherein v is the velocity vector of a GPS satellite; a is a unit directional vector; and c is the velocity of light). The carrier wave of the received GPS signal is measured to obtain a measured Doppler shift amountΔf. A differenceΔf' betweenΔf andΔfr is calculated, and whenΔf' is equal to or larger than a prescribed threshold value, it is judged that the received signal is a multipass, and a GPS positioning operation is performed after eliminating the GPS signal judged as a multipass. |
