EFFICIENT USE OF EXPECTED USER ALTITUDE DATA TO AID IN DETERMINING POSITION OF MOBILE STATION

摘要

PROBLEM TO BE SOLVED: To provide a method of calculating a three-dimensional position of a point to be positioned in a short time by using a terrain database available for a memory of a mobile station having severe capacity limitations.;SOLUTION: An initial position is calculated on the basis of a global coarse altitude estimate and at least three global positioning system satellite measurements. One of databases including only the most populous areas or specific regions is identified on the basis of the initial position, instead of using the entire terrain model of the earth or an entire country as an altitude estimate and a terrain database. This reduces the size of the information in the database, which in turn reduces the amount of time to compute the position of a wireless device.;COPYRIGHT: (C)2015,JPO&INPIT