uNav公司的GPS系统简介

GPS Tutorial 1GPS Tutorial # 1
Overview

Darren Sessions

GPS Overview


GPS System Calculating a Position Receiver Outputs Accuracy and Availability







GPS System


NAVSTAR GPS
Navigation Satellite Timing and Ranging Global Positioning System Funded and controlled by U. S. Department of Defense.




Comprised of three segments
Space Segment Control Segment User Segment


Space Segment


Space segment consists of the GPS space vehicles (SVs). Nominally 24 SVs plus spares.
Each vehicle has a12 hour orbit. Repeats same ground track daily. 6 orbital planes with 4 vehicles each. Planes are equally spaced 60 degrees apart. Inclined 55 degrees from equatorial plane. 20,200 km above the earth. 5 to 8 SVs visible from anywhere on earth.


Space Segment

Control Segment


SVs are controlled by