Patent ID: 7557750
Filing Date: 2009-07-07
Classification: G01S

Abstract:
1. A positioning device comprising: an estimated height storage section which stores an estimated height; a signal reception section which receives a satellite signal which is a signal from a satellite positioning system (SPS) satellite; a two-dimensional height calculation section which calculates a height of a present position as a two-dimensional height by performing two-dimensional positioning which locates the present position based on the received satellite signals using the estimated height as a distance from the center of the earth; a three-dimensional height calculation section which calculates the height of the present position as a three-dimensional height by performing preliminary three-dimensional positioning which preliminarily locates the present position based on the received satellite signals without using the estimated height when performing the two-dimensional positioning; a height selection section which selects the two-dimensional height or the three-dimensional height for updating the estimated height stored in the estimated height storage section; and an updating section which updates the estimated height stored in the estimated height storage section using the two-dimensional height or the three-dimensional height selected by the height selection section.