×

Global positioning system tag system

  • US 20040030496A1
  • Filed: 06/20/2003
  • Published: 02/12/2004
  • Est. Priority Date: 04/30/1999
  • Status: Active Grant
First Claim
Patent Images

1. A communications system for determining the position of an object, said system comprising:

  • an interrogator remote from the object and adapted to;

    receive GPS signals from GPS satellites;

    transmit pre-positioning data for each of the received GPS signals including the pseudorandom noise (PRN) code number, Doppler frequency offset and code phase offset and a tracking signal including reference time and frequency information; and

    determine the pseudorange associated with at least one of the GPS signals using a subsequently received correlation snapshot; and

    a transponder positioned on the object and adapted to;

    receive the pre-positioning data and tracking signal;

    collect RF samples of at least one of the GPS signals associated with one of the PRN code numbers;

    correlate the RF samples of the GPS signal against code replicas of the GPS signal based on the Doppler frequency offset, code phase offset and reference time and frequency information for that GPS signal to produce the correlation snapshot; and

    transmit the correlation snapshot to the interrogator.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×