Patent ID: 8339310

Claim:
A positioning method for a positioning device comprising: executing a first positioning mode or a second positioning mode, an LS positioning process that is performed using a least-square method based on a positioning signal and a KF positioning process that is performed using a Kalman filter based on the positioning signal utilizing a positioning result obtained by the LS positioning process as a base value being performed in the first positioning mode, and the KF positioning process being further performed in the second positioning mode utilizing a positioning result obtained by the KF positioning process as a base value; determining the accuracy of a positioning result obtained by the KF positioning process performed in the positioning mode that has been currently executed; changing the positioning mode to be subsequently executed to the first positioning mode or the second positioning mode based on a result of the accuracy determination; determining an elapsed time from the preceding KF positioning process; and determining whether or not to perform the KF positioning process in the positioning mode to be subsequently executed based on a result of the elapsed time determination.