US5774829A — Navigation and positioning system and method usin…

Claim 1

Independent Claim 208 words

A positioning system for determining location of a mobile unit, said system making use of a multiplicity of transmitters, at known locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals being of a predetermined repetition rate, said system comprising: an uncoordinated beacon positioning subsystem (UBS), said subsystem including a UBS receiver for receiving said beacon signals and for providing a UBS location of said mobile unit; an absolute positioning subsystem (APS) including an APS receiver for receiving APS signals and for providing an APS location of said mobile unit; and a processor for determining uncertainty of location information provided by said beacon signal receiver and said APS receiver, and updating a current location of said mobile unit based on said UBS and APS locations and said uncertainty of said location information; wherein the processor determines the uncertainty of location information for the APS receiver by measuring and evaluating at least one signal parameter associated with the APS signals, and determines the uncertainty of location information for the UBS receiver by measuring and evaluating at least one signal parameter associated with the received beacon signals.

Claim 2

Dependent Claim 208 words

A positioning system for determining location of a mobile unit, said system making use of a multiplicity of transmitters, at known locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals being of a predetermined repetition rate, said system comprising: an uncoordinated beacon positioning subsystem (UBS), said subsystem including a UBS receiver for receiving said beacon signals and for providing a UBS location of said mobile unit; an absolute positioning subsystem (APS) including an APS receiver for receiving APS signals and for providing an APS location of said mobile unit; and a processor for determining uncertainty of location information provided by said beacon signal receiver and said APS receiver, and updating a current location of said mobile unit based on said UBS and APS locations and said uncertainty of said location information; wherein the processor determines the uncertainty of location information for the APS receiver by measuring and evaluating at least one signal parameter associated with the APS signals, and determines the uncertainty of location information for the UBS receiver by measuring and evaluating at least one signal parameter associated with the received beacon signals.

Claim 3

Dependent Claim 39 words

The positioning system of claim 1, wherein said APS receiver comprises a global positioning system (GPS) receiver for receiving GPS signals, said processor including software for computing an indication of quality of location information provided by said GPS receiver.

Claim 4

Dependent Claim 22 words

The positioning system of claim 1, wherein said UBS receiver includes logic for computing an indication of quality of said UBS location.

Claim 5

Dependent Claim 45 words

The positioning system of claim 1, wherein said processor includes software for assigning said APS location to said UBS location when uncertainty of location information provided by said APS receiver is determined to be less than uncertainty of location information provided by said UBS receiver.

Claim 6

Dependent Claim 37 words

The positioning system of claim 1, wherein said processor includes software for assigning said APS location to said UBS location when uncertainty of location information provided by said UBS receiver is determined to exceed a predetermined level.

Claim 7

Dependent Claim 74 words

The positioning system of claim 1, wherein said UBS receiver includes a beacon signal receiver for receiving at least two of said beacon signals, said beacon signal receiver including phase detection circuitry for detecting the phases of at least three of said beacon signals at the location of said mobile unit, and processor for computing said UBS location based on said detected phases and on an initial location estimate provided by said APS receiver.

Claim 8

Dependent Claim 37 words

The positioning system of claim 1, wherein said processor includes software for assigning said UBS location to said APS location when uncertainty of location information provided by said APS receiver is determined to exceed a predetermined level.

Claim 9

Dependent Claim 30 words

The positioning system of claim 1, wherein said UBS receiver also receives local traffic information from one of said multiplicity of transmitters, said local traffic information being useable for navigation.

Claim 10

Dependent Claim 72 words

The positioning system of claim 1, wherein the processor, when the determined uncertainty of the UBS location is less than the determined uncertainty of the APS location, updates the current position in a manner selected from the set consisting of (A) based solely on the UBS location, and (B) based on a weighted combination of the UBS and APS locations wherein the UBS location is weighted more heavily than the APS location.

Claim 11

Dependent Claim 288 words

A positioning system for determining position of a mobile unit, comprising: a multiplicity of transmitters, at known locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters; each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency; a first receiver, at a known location relative to the locations of said multiplicity of transmitters, which (A) receives said beacon signals, (B) determines the relative phases of said beacon signals, and (C) broadcasts phase data representing said relative phases; a second receiver, disposed within said mobile unit, which receives said broadcast phase data from said first receiver and at least three of said beacon signals, said second receiver including phase detection circuitry for detecting the phases of said beacon signals at the location of said mobile unit, and data processing circuitry for computing a first estimated location of said mobile unit based on said broadcast values and said detected phases; an absolute positioning system (APS) receiver, disposed within said mobile unit, for receiving APS signals and for providing a second estimated location of said mobile unit; and a processor for evaluating positional uncertainty in said first and second estimated locations, and for updating a current position of said mobile unit based on said first and second estimated locations of said mobile unit and said positional uncertainty; wherein the processor determines the uncertainty of the first estimated location by measuring and evaluating at least one signal parameter associated with the beacon signals, and determines the uncertainty of the second estimated location by measuring and evaluating at least one signal parameter associated with the received APS signals.

Claim 12

Dependent Claim 288 words

A positioning system for determining position of a mobile unit, comprising: a multiplicity of transmitters, at known locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters; each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency; a first receiver, at a known location relative to the locations of said multiplicity of transmitters, which (A) receives said beacon signals, (B) determines the relative phases of said beacon signals, and (C) broadcasts phase data representing said relative phases; a second receiver, disposed within said mobile unit, which receives said broadcast phase data from said first receiver and at least three of said beacon signals, said second receiver including phase detection circuitry for detecting the phases of said beacon signals at the location of said mobile unit, and data processing circuitry for computing a first estimated location of said mobile unit based on said broadcast values and said detected phases; an absolute positioning system (APS) receiver, disposed within said mobile unit, for receiving APS signals and for providing a second estimated location of said mobile unit; and a processor for evaluating positional uncertainty in said first and second estimated locations, and for updating a current position of said mobile unit based on said first and second estimated locations of said mobile unit and said positional uncertainty; wherein the processor determines the uncertainty of the first estimated location by measuring and evaluating at least one signal parameter associated with the beacon signals, and determines the uncertainty of the second estimated location by measuring and evaluating at least one signal parameter associated with the received APS signals.

Claim 13

Dependent Claim 78 words

The positioning system of claim 10, wherein the processor, when the determined uncertainty of the first estimated location is less than the determined uncertainty of the second estimated location, updates the current position in a manner selected from the set consisting of (A) based solely on the first estimated location, and (B) based on a weighted combination of the first and second estimated locations wherein the first estimated location is weighted more heavily than the second estimated location.

Claim 14

Dependent Claim 234 words

A positioning system, comprising: a multiplicity of transmitters, at known locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters; each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency; and a mobile unit including: a beacon signal receiver for receiving at least three of said beacon signals, said beacon signal receiver including phase detection circuitry for detecting the phases of the at least three of said beacon signals received thereby, an absolute positioning system (APS) receiver for receiving APS signals and for estimating an initial position of said mobile unit therefrom, and a processor for computing a current location of said mobile unit based on: (i) said detected phases of the at least three of said beacon signals, and (ii) said estimate of said initial position; said processor including: a memory for storing estimates of location of said mobile unit made by said APS receiver at first and second calibration times, and for storing phases and frequencies of said beacon signals received from a plurality of said transmitters at said first and second calibration times, and software for determining phase and frequency drift of said beacon signals based on said stored estimates of location of said mobile unit and said stored phases and frequencies of said beacon signals.

Claim 15

Dependent Claim 234 words

A positioning system, comprising: a multiplicity of transmitters, at known locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters; each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency; and a mobile unit including: a beacon signal receiver for receiving at least three of said beacon signals, said beacon signal receiver including phase detection circuitry for detecting the phases of the at least three of said beacon signals received thereby, an absolute positioning system (APS) receiver for receiving APS signals and for estimating an initial position of said mobile unit therefrom, and a processor for computing a current location of said mobile unit based on: (i) said detected phases of the at least three of said beacon signals, and (ii) said estimate of said initial position; said processor including: a memory for storing estimates of location of said mobile unit made by said APS receiver at first and second calibration times, and for storing phases and frequencies of said beacon signals received from a plurality of said transmitters at said first and second calibration times, and software for determining phase and frequency drift of said beacon signals based on said stored estimates of location of said mobile unit and said stored phases and frequencies of said beacon signals.

Claim 16

Dependent Claim 90 words

The positioning system of claim 12, wherein said APS receiver comprises a global positioning system (GPS) receiver and wherein said processor includes: a memory for storing GPS time indications extracted from GPS signals received by said GPS receiver at first and second calibration times, and for storing local time indications registered by a local clock within said mobile unit at said first and second calibration times, and software for calibrating said local clock by comparing a difference between said local time indications to a difference between said GPS time indications.

Claim 17

Dependent Claim 77 words

The positioning system of claim 12, wherein said processor includes: a memory for storing APS time indications extracted from said APS signals received by said APS receiver at first and second calibration times, and for storing local time indications registered by a local clock within said mobile unit at said first and second calibration times, and software for calibrating said local clock by comparing difference between said local time indications to difference between said APS time indications.

Claim 18

Dependent Claim 54 words

The positioning system of claim 12, said beacon signal receiver including circuitry for acquiring position data specifying the positions of said multiplicity of transmitters; said processor including software for performing a predefined position computation using said position data to generate a position value for said mobile unit which is consistent with said position data.

Claim 19

Dependent Claim 28 words

The positioning system of claim 12, wherein said beacon signal transmitted by each of said transmitters comprise FM radio station pilot signals having frequencies of approximately 19 kHz.

Claim 20

Dependent Claim 29 words

The positioning system of claim 12, wherein said APS receiver comprises a receiver selected from the set consisting of: a global positioning system (GPS) receiver and a LORAN receiver.

Claim 21

Dependent Claim 26 words

The positioning system of claim 12, wherein said APS receiver comprises a receiver selected from the set consisting of: an OMEGA receiver and a TRANSIT receiver.

Claim 22

Dependent Claim 31 words

The positioning system of claim 12, wherein said beacon signal receiver also receives local traffic information from one of said multiplicity of transmitters, said local traffic information being useable for navigation.

Claim 23

Dependent Claim 209 words

In a positioning system which makes use of: (i) an uncoordinated beacon positioning subsystem (UBS), said subsystem including a multiplicity of transmitters, at known fixed locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency, and (ii) global positioning system (GPS) signals transmitted by a multiplicity of GPS satellites, a method for determining location of a mobile unit, said method comprising the steps of: receiving a plurality of said beacon signals and determining a UBS location of said mobile unit therefrom; receiving a plurality of said GPS signals and determining a GPS location of said mobile unit therefrom; and determining uncertainty of said GPS and UBS locations, and updating a current location of said mobile unit based on said UBS and GPS locations and said uncertainty thereof; wherein the determining step includes determining the uncertainty of GPS location by measuring and evaluating at least one signal parameter associated with the GPS signals, and determining the uncertainty of UBS location by measuring and evaluating at least one signal parameter associated with the received beacon signals.

Claim 24

Dependent Claim 209 words

In a positioning system which makes use of: (i) an uncoordinated beacon positioning subsystem (UBS), said subsystem including a multiplicity of transmitters, at known fixed locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency, and (ii) global positioning system (GPS) signals transmitted by a multiplicity of GPS satellites, a method for determining location of a mobile unit, said method comprising the steps of: receiving a plurality of said beacon signals and determining a UBS location of said mobile unit therefrom; receiving a plurality of said GPS signals and determining a GPS location of said mobile unit therefrom; and determining uncertainty of said GPS and UBS locations, and updating a current location of said mobile unit based on said UBS and GPS locations and said uncertainty thereof; wherein the determining step includes determining the uncertainty of GPS location by measuring and evaluating at least one signal parameter associated with the GPS signals, and determining the uncertainty of UBS location by measuring and evaluating at least one signal parameter associated with the received beacon signals.

Claim 25

Dependent Claim 28 words

The method of claim 20 wherein said step of determining uncertainty includes the step of computing a dilution of precision associated with said plurality of received GPS signals.

Claim 26

Dependent Claim 28 words

The method of claim 21 wherein said step of determining uncertainty includes the step of computing a UBS dilution of precision associated with said plurality of beacon signals.

Claim 27

Dependent Claim 35 words

The method of claim 20 further including the step of assigning said APS location to said UBS location when uncertainty of said APS location is determined to be less than uncertainty of said UBS location.

Claim 28

Dependent Claim 35 words

The method of claim 23 further including the step of assigning said UBS location to said APS location when uncertainty of said UBS location is determined to be less than uncertainty of said APS location.

Claim 29

Dependent Claim 55 words

The method of claim 20 wherein said step of determining a UBS location includes the steps of: receiving at least three of said beacon signals, detecting the phases of at least three of said beacon signals at the location of said mobile unit, and computing a change in UBS location based upon said detected phases.

Claim 30

Dependent Claim 26 words

The method of claim 20, further including receiving local traffic information from one of said multiplicity of transmitters, said local traffic information being useable for navigation.

Claim 31

Dependent Claim 73 words

The method of claim 20, wherein the determining step includes, when the determined uncertainty of the UBS location is less than the determined uncertainty of the APS location, updating the current position in a manner selected from the set consisting of (A) based solely on the UBS location, and (B) based on a weighted combination of the UBS and APS locations wherein the UBS location is weighted more heavily than the APS location.

Claim 32

Dependent Claim 293 words

In a positioning system which makes use of an uncoordinated beacon positioning subsystem and an absolute positioning subsystem (APS), said uncoordinated beacon positioning subsystem including a multiplicity of transmitters, at known fixed locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency, a method for determining location of a mobile unit comprising the steps of: at a known location relative to the locations of said multiplicity of transmitters, receiving said beacon signals, determining the relative phases of said beacon signals, and broadcasting phase data representing said relative phases; at said mobile unit, receiving said broadcast phase data and receiving at least three of said beacon signals, detecting the phases of said beacon signals received at said mobile unit, and computing a first estimated location of said mobile unit based on said broadcast values and said detected phases; at said mobile unit, receiving APS signals generated at known locations within a coordinated system of said APS subsystem, and providing a second estimated location of said mobile unit using said received APS signals; and evaluating positional uncertainty in said first and second estimated locations, and updating a current position of said mobile unit based on said first and second estimated locations of said mobile unit and said positional uncertainty; wherein the evaluating step includes determining the uncertainty of the first estimated location by measuring and evaluating at least one signal parameter associated with the beacon signals, and determining the uncertainty of the second estimated location by measuring and evaluating at least one signal parameter associated with the received APS signals.

Claim 33

Dependent Claim 293 words

In a positioning system which makes use of an uncoordinated beacon positioning subsystem and an absolute positioning subsystem (APS), said uncoordinated beacon positioning subsystem including a multiplicity of transmitters, at known fixed locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency, a method for determining location of a mobile unit comprising the steps of: at a known location relative to the locations of said multiplicity of transmitters, receiving said beacon signals, determining the relative phases of said beacon signals, and broadcasting phase data representing said relative phases; at said mobile unit, receiving said broadcast phase data and receiving at least three of said beacon signals, detecting the phases of said beacon signals received at said mobile unit, and computing a first estimated location of said mobile unit based on said broadcast values and said detected phases; at said mobile unit, receiving APS signals generated at known locations within a coordinated system of said APS subsystem, and providing a second estimated location of said mobile unit using said received APS signals; and evaluating positional uncertainty in said first and second estimated locations, and updating a current position of said mobile unit based on said first and second estimated locations of said mobile unit and said positional uncertainty; wherein the evaluating step includes determining the uncertainty of the first estimated location by measuring and evaluating at least one signal parameter associated with the beacon signals, and determining the uncertainty of the second estimated location by measuring and evaluating at least one signal parameter associated with the received APS signals.

Claim 34

Dependent Claim 26 words

The method of claim 28, further including receiving local traffic information from one of said multiplicity of transmitters, said local traffic information being useable for navigation.

Claim 35

Dependent Claim 79 words

The method of claim 28, wherein the determining step includes, when the determined uncertainty of the first estimated location is less than the determined uncertainty of the second estimated location, updating the current position in a manner selected from the set consisting of (A) based solely on the first estimated location, and (B) based on a weighted combination of the first and second estimated locations wherein the first estimated location is weighted more heavily than the second estimated location.

Claim 36

Independent Claim 256 words

A method of determining a mobile unit's current location with respect to the positions of a multiplicity of transmitters that are positioned at known locations, wherein each transmitter transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency, the steps of the method comprising: receiving, at said mobile unit, at least three of said beacon signals, and detecting the phases of the at least three of said beacon signals received at said mobile unit; receiving, at said mobile unit, signals provided by an absolute positioning system (APS), and estimating an initial position of said mobile unit using said APS signals received at said mobile unit; and computing said current location of said mobile unit based on: (i) said detected phases of the at least three of said beacon signals, and (ii) said estimate of said initial position; said step of computing includes the steps of: estimating location of said mobile unit based on APS signals received at said mobile unit at first and second calibration times, and storing phases and frequencies of ones of said beacon signals received from a plurality of said transmitters at said first and second calibration times, and determining phase and frequency drift and drift rates of said beacon signals based on said stored estimates of location of said mobile unit and said stored phases and frequencies of said beacon signals.

Claim 37

Independent Claim 256 words

A method of determining a mobile unit's current location with respect to the positions of a multiplicity of transmitters that are positioned at known locations, wherein each transmitter transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency, the steps of the method comprising: receiving, at said mobile unit, at least three of said beacon signals, and detecting the phases of the at least three of said beacon signals received at said mobile unit; receiving, at said mobile unit, signals provided by an absolute positioning system (APS), and estimating an initial position of said mobile unit using said APS signals received at said mobile unit; and computing said current location of said mobile unit based on: (i) said detected phases of the at least three of said beacon signals, and (ii) said estimate of said initial position; said step of computing includes the steps of: estimating location of said mobile unit based on APS signals received at said mobile unit at first and second calibration times, and storing phases and frequencies of ones of said beacon signals received from a plurality of said transmitters at said first and second calibration times, and determining phase and frequency drift and drift rates of said beacon signals based on said stored estimates of location of said mobile unit and said stored phases and frequencies of said beacon signals.

Claim 38

Dependent Claim 86 words

The method of claim 31 wherein said absolute positioning system comprises the global positioning system (GPS), and wherein said step of computing includes the steps of: storing GPS time indications extracted from GPS signals received at said mobile unit at first and second calibration times, and storing local time indications registered by a local clock within said mobile unit at said first and second calibration times, and calibrating said local clock by comparing difference between said local time indications to difference between said GPS time indications.

Claim 39

Dependent Claim 21 words

The method of claim 31 further including the step of receiving, at said mobile unit, local traffic information useable for navigation.

Claim 40

Dependent Claim 293 words

In a positioning system which makes use of: (A) an uncoordinated beacon positioning subsystem, said uncoordinated beacon positioning subsystem including a multiplicity of transmitters, at known fixed locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency, and (B) a multiplicity of global positioning system (GPS) satellites, each of which transmits a GPS signal having a predefined phase relationship to the GPS signals transmitted by the other satellites, wherein each of said GPS signals includes information indicative of a position of the GPS satellite within a GPS coordinate system at the time of transmission of the GPS signal therefrom; a method for determining location of a mobile unit comprising the steps of: at said mobile unit, (i) receiving at least three of said beacon signals and computing a first set of estimated ranges between a current position of said mobile unit within said predefined coordinate system and the three of said beacon signal transmitters from which were transmitted said at least three of said beacon signals; (ii) receiving a plurality of said GPS signals and computing a second set of estimated ranges between a current position of said mobile unit within said GPS coordinate system and said GPS satellites from which were transmitted said plurality of GPS signals; (iii) forming a set of simultaneous position equations based on said first and second sets of estimated ranges, said set of simultaneous position equations being referenced to said GPS coordinate system; and (iv) solving said set of simultaneous equations in order to determine said current location of said mobile unit.

Claim 41

Dependent Claim 293 words

In a positioning system which makes use of: (A) an uncoordinated beacon positioning subsystem, said uncoordinated beacon positioning subsystem including a multiplicity of transmitters, at known fixed locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency, and (B) a multiplicity of global positioning system (GPS) satellites, each of which transmits a GPS signal having a predefined phase relationship to the GPS signals transmitted by the other satellites, wherein each of said GPS signals includes information indicative of a position of the GPS satellite within a GPS coordinate system at the time of transmission of the GPS signal therefrom; a method for determining location of a mobile unit comprising the steps of: at said mobile unit, (i) receiving at least three of said beacon signals and computing a first set of estimated ranges between a current position of said mobile unit within said predefined coordinate system and the three of said beacon signal transmitters from which were transmitted said at least three of said beacon signals; (ii) receiving a plurality of said GPS signals and computing a second set of estimated ranges between a current position of said mobile unit within said GPS coordinate system and said GPS satellites from which were transmitted said plurality of GPS signals; (iii) forming a set of simultaneous position equations based on said first and second sets of estimated ranges, said set of simultaneous position equations being referenced to said GPS coordinate system; and (iv) solving said set of simultaneous equations in order to determine said current location of said mobile unit.

Claim 42

Dependent Claim 50 words

The method of claim 34 wherein said forming step includes forming said set of simultaneous position equations using four range estimates included within said first and second sets of estimated ranges, said set of simultaneous position equations being referenced to said GPS coordinate system and to a GPS time system.

Claim 43

Dependent Claim 216 words

A positioning system for determining location of a mobile unit, said system making use of a multiplicity of transmitters, at known locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals being of a predetermined repetition rate, said system comprising: an uncoordinated beacon positioning subsystem (UBS), said subsystem including a UBS receiver for receiving said beacon signals and for generating a UBS pseudorange residual signal; an absolute positioning subsystem (APS) including an APS receiver for receiving APS signals and for generating an APS pseudorange residual signal, said APS receiving including a code loop detector that generates said APS pseudorange residual signal and a code loop oscillator in a feedback arrangement with said code loop detector; and an estimator for filtering and combining said UBS pseudorange residual signal and said ABS pseudorange residual signal to generate a velocity signal used to control said code loop oscillator in said APS and to generate a change-in-position signal; said feedback arrangement in said APS including apparatus for combining said change-in-position signal with a signal generated by said code loop oscillator to generate an a priori APS pseudorange signal that is feed back to said code loop detector.

Claim 44

Dependent Claim 216 words

A positioning system for determining location of a mobile unit, said system making use of a multiplicity of transmitters, at known locations, each of which transmits a beacon signal having a phase that is at least partially un-synchronized with the phases of the beacon signals of the other transmitters, each of said beacon signals being of a predetermined repetition rate, said system comprising: an uncoordinated beacon positioning subsystem (UBS), said subsystem including a UBS receiver for receiving said beacon signals and for generating a UBS pseudorange residual signal; an absolute positioning subsystem (APS) including an APS receiver for receiving APS signals and for generating an APS pseudorange residual signal, said APS receiving including a code loop detector that generates said APS pseudorange residual signal and a code loop oscillator in a feedback arrangement with said code loop detector; and an estimator for filtering and combining said UBS pseudorange residual signal and said ABS pseudorange residual signal to generate a velocity signal used to control said code loop oscillator in said APS and to generate a change-in-position signal; said feedback arrangement in said APS including apparatus for combining said change-in-position signal with a signal generated by said code loop oscillator to generate an a priori APS pseudorange signal that is feed back to said code loop detector.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2001-06-29	2001-12-29	2002-06-30	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2005-06-29	2005-12-29	2006-06-30	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2009-06-29	2009-12-29	2010-06-30	$7700.00	Window Closed / Lapsed

Navigation and positioning system and method using uncoordinated beacon signals in conjunction with an absolute positioning system

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