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US5739786A Expired / Lapsed US ⏱️ 0.0 years remaining

GPS transfer initialization system

Assignee: Charles Stark Draper Laboratory Inc
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Filing: 1996-06-12
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Granted: 1998-04-14
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Expires: 2016-06-12
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Abstract

Abstract A GPS transfer initialization system for initializing a mobile unit from a base unit, includes a GPS receiver in the mobile unit for receiving a GPS signal including a time register, a frequency register, and a GPS reference oscillator for generating a GPS carrier signal of a first frequency; a mobile transmitter/receiver circuit on the mobile unit responsive to the GPS carrier signal, for generating and transmitting a transfer carrier signal of a second frequency that is a multiple of the first frequency; a base transmitter/receiver circuit on the base unit including a GPS calibrated frequency and time reference for providing a GPS calibrated signal of a third frequency; an error detection circuit for comparing the GPS calibrated signal and the transfer carder signal to generate a frequency error signal determined from the difference between them and representative of the error in the frequency of the GPS reference oscillator; and an error correction circuit responsive to the GPS calibrated frequency and time reference and to the error detection circuit for generating and transmitting the GPS time and error signal; the mobile transmitter/receiver circuit including an initializing circuit responsive to the GPS time and the error signal for adjusting the time register and frequency register to the correct GPS time and frequency.

Inventors

  • 👤 Richard L. Greenspan
  • 👤 Joseph M. Przyjemski

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 12:15
CPC Classifications
G; G01; G01S; G01S19/00; G01S19/01; G01S19/13; G01S19/23; G01S19/235; G01S19/03; G01S19/14; G01S19/18; G01S19/21; G01S19/215; G01S2205/00; G01S2205/001; G01S2205/002; G01S2205/003

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 212 words
A GPS Transfer Initialization System for initializing a mobile unit from a base unit, comprising: a GPS receiver in the mobile unit for receiving a GPS signal including a time register, a frequency register, and a GPS reference oscillator for generating a GPS carrier signal of a first frequency; a mobile transmitter/receiver circuit on said mobile unit responsive to said GPS carrier signal, for generating and transmitting a transfer carder signal of a second frequency that is a multiple of said first frequency; a base transmitter/receiver circuit on the base unit including: a GPS calibrated frequency and time reference for providing a GPS calibrated signal of a third frequency; an error detection circuit for comparing said GPS calibrated signal and said transfer cartier signal to generate a frequency error signal determined from the difference between them and representative of the error in the frequency of said GPS reference oscillator; and an error correction circuit responsive to said GPS calibrated frequency and time reference and to said error detection circuit for generating and transmitting the GPS time and said error signal; said mobile transmitter/receiver circuit including an initializing circuit responsive to said GPS time and said error signal for adjusting said time register and frequency register to the correct GPS time and frequency.
Claim 2
Dependent Claim 212 words
A GPS Transfer Initialization System for initializing a mobile unit from a base unit, comprising: a GPS receiver in the mobile unit for receiving a GPS signal including a time register, a frequency register, and a GPS reference oscillator for generating a GPS carrier signal of a first frequency; a mobile transmitter/receiver circuit on said mobile unit responsive to said GPS carrier signal, for generating and transmitting a transfer carder signal of a second frequency that is a multiple of said first frequency; a base transmitter/receiver circuit on the base unit including: a GPS calibrated frequency and time reference for providing a GPS calibrated signal of a third frequency; an error detection circuit for comparing said GPS calibrated signal and said transfer cartier signal to generate a frequency error signal determined from the difference between them and representative of the error in the frequency of said GPS reference oscillator; and an error correction circuit responsive to said GPS calibrated frequency and time reference and to said error detection circuit for generating and transmitting the GPS time and said error signal; said mobile transmitter/receiver circuit including an initializing circuit responsive to said GPS time and said error signal for adjusting said time register and frequency register to the correct GPS time and frequency.
Claim 3
Dependent Claim 19 words
The GPS transfer initialization system of claim 1 in which the mobile unit is included on an ordinance projectile.
Claim 4
Dependent Claim 18 words
The GPS transfer initialization system of claim 1 in which said base transmitter/receiver circuit includes a directional antenna.
Claim 5
Dependent Claim 18 words
The GPS transfer initialization system of claim 1 in which said mobile transmitter/receiver circuit includes a directional antenna.
Claim 6
Dependent Claim 20 words
The GPS transfer initialization system of claim 1 in which said second frequency transfer carrier signal is approximately 30-300 GHz.
Claim 7
Dependent Claim 20 words
The GPS transfer initialization system of claim 1 in which said second frequency transfer carrier signal is approximately 40-60 GHz.

References Cited (Backward Citations)

US5319374A Cited
US5510797A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-04-13 2001-10-13 2002-04-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-04-13 2005-10-13 2006-04-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-04-13 2009-10-13 2010-04-14 $7700.00 Window Closed / Lapsed

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