Patent ID: 6825801
Filing Date: 2004-11-30
Classification: G01S

Abstract:
A global positioning system satellite emulator for testing the capacity of a GPS system receiver to receive, demodulate and process navigation data and coarse acquisition code comprising:an oscillator; a radio frequency bi-phase shift key modulator receiving an input from the oscillator; a clock signal generator circuit receiving input from the oscillator, for generating a clock signal; a G-epoch generator circuit receiving an input from the clock signal generator circuit and for outputting a G-epoch signal, at a frequency different from the clock signal; a first linear feedback shift register receiving the G-epoch signal and the clock signal, and for outputting a G-1 signal; space vehicle select circuitry including a first EPROM including a set of user activated switches for encoding said first EPROM with G-2 signal delay data for emulating the G-2 signal of a selected satellite; a navigation message generator circuit receiving input of the G-epoch signal, said navigation message generator circuit having a second EPROM for storing and outputting a navigation message; and glitch elimination circuitry.