The almanac data from the GPS accepting station and GPS standard station

摘要

PROBLEM TO BE SOLVED: To provide a GPS receiving terminal, a GPS reference station and a computer software capable of improving reliability in positioning by a GPS positioning system, capable of picking up at least three satellites with high probability, especially even in a poor positioning environment, such as in urban area or mountainous region.;SOLUTION: The GPS receiving terminal 1 comprises a GPS receiving part 11 for receiving an almanac data and an Ephemeris data from the GPS satellites 3; an orbit estimating part 14 for estimating the GPS orbits, by using the received almanac data; a positioning process part 13 for positioning process by using Ephemeris data; and a communication part 12 for data transmission/reception to/from a GPS reference station 2. The communication part 12 receives the Ephemeris data from the GPS reference station 2, before an unsuitable time zone for GPS positioning, such as the time zone supposed to be reduced in number of visible GPS satellites, or the time zone to be increased in number of switching of visible GPS satellite.;COPYRIGHT: (C)2004,JPO&NCIPI