Patent ID: 8521179

Claim:
A mobile unit's position measurement apparatus comprising: a reception portion that receives signals from a plurality of satellites; an observation data selection portion that calculates a plurality of estimated error values that correspond respectively to a plurality of pieces of observation data obtained by observing the signals received by the reception portion, that generates groups, each of which includes estimated error values corresponding to at least a predetermined number of satellites, and then extracts, from the estimated error value groups generated, estimated error value groups in which a difference between a maximum value and a minimum value of the estimated error values included is less than a predetermined value, and that consequently selects pieces of observation data provided by the signals from the satellites that correspond to the estimated error values that are included in an estimated error value group whose standard deviation of the estimated error values is smallest among the estimated error value groups extracted; and a positioning computation portion that performs a positioning computation based on the pieces of observation data selected by the observation data selection portion.