SATELLITE NAVIGATION SYSTEM

• Main Author: HIRATA SEIICHIRO
• Format: Patent
• Language: English
• Published: 05.03.1992
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; GYROSCOPIC INSTRUMENTS; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; MEASURING DISTANCES, LEVELS OR BEARINGS; NAVIGATION; PHOTOGRAMMETRY OR VIDEOGRAMMETRY; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; SURVEYING; TESTING

PURPOSE:To obtain exact two-dimensional position measurement data of a moving body by requesting the altitude data of this time from an altitude deviation accompanying the altitude data of the previous data and the movement of a moving body to compoute the two-dimensional position measurement data of the moving body in the case where the number of satellites is 3 or less. CONSTITUTION:At first, a signal A of a Global Position System (GPS) included in a Z wave of a position measurement satellite is received through an antenna 1 and a GPS receiving part 2. A judgement part 3 judges whether the number N of satelites is 4 and more or not on the basis of a received signal A to output a control signal B into a position operation part 8. If the number N of the satellites 4 and more, the operation part 8 performs normal three-dimensional position measurement operation. In the case where the number N of the satelites is 3, the operation part 8 reads the altitude data H of the previous time from an altitude storage part 7, an altitude deviation calculation part 6 calculates an atmospheric deviation accompanying the movement of the moving body from the output of an atmosphere sensor 4 to calculate the altitude deviation DELTAH accompanying the movement thereof as DELTAH = F(DELTAP). Next the altitude of the present time is calculated to store this value as data H into the storage part 7 so as to calculate to output the two-dimensional position measurement data on the basis of the signal a and data H.