US2017038404A1PendingUtilityA1

Propagation medium velocity measurement system

44
Individually held — no corporate assignee on recordPriority: Feb 10, 2014Filed: Aug 9, 2016Published: Feb 9, 2017
Est. expiryFeb 10, 2034(~7.5 yrs left)· nominal 20-yr term from priority
Inventors:Selwyn WrightKelvin F. Wright
G01P 3/36G01S 11/12G01S 11/02
44
PatentIndex Score
0
Cited by
0
References
0
Claims

Abstract

An apparatus measures an electromagnetic signal (e.g., light) propagation time delay that varies with system speed relative to its propagation medium. A one-way light propagation time measurement in the medium between two fixed points moving relative to the medium is used. The delay is compared with light propagating in a constant reference path that is independent of motion. A two-way system is also used, as well as increasing sensitivity through a light zigzag and fiber optic coil delay. The apparatus is a compact and extremely sensitive speedometer.

Claims

exact text as granted — not AI-modified
We claim: 
     
         1 . A method of measuring a velocity of an apparatus, said method comprising:
 while said apparatus is at a reference velocity, transmitting a first portion of an electromagnetic beam via a first path on said apparatus to a receiver, wherein a distance said first portion travels via said first path is dependent on any velocity of said apparatus;   while said apparatus is at said reference velocity, transmitting a second portion of said beam via a second path on said apparatus to said receiver, wherein a distance said second portion travels via said second path is independent of any velocity of said apparatus;   determining a reference phase difference at said receiver between said first portion traveling via said first path at said reference velocity and said second portion traveling via said second path at said reference velocity;   while said apparatus is at said velocity, determining a velocity phase difference at said receiver between said first portion traveling via said first path and said second portion traveling via said second path;   determining a total phase difference between said velocity phase difference and said reference phase difference; and   calculating said velocity of said apparatus using at least said total phase difference, a frequency of said beam, and the speed of light.   
     
     
         2 . The method as recited in  claim 1  wherein said reference velocity is zero relative to the surface of the Earth. 
     
     
         3 . The method as recited in  claim 1  wherein said first portion traveling via said first path travels in the direction of said velocity of said apparatus. 
     
     
         4 . The method as recited in  claim 1  wherein said first portion traveling via said first path propagates in a propagation medium. 
     
     
         5 . The method as recited in  claim 1  wherein said first path includes a zigzag portion. 
     
     
         6 . The method as recited in  claim 1  wherein said first path includes a solid medium that is longer than the distance between a source of said beam and said receiver. 
     
     
         7 . An apparatus for calculating a velocity of said apparatus, said apparatus comprising:
 a receiver;   a source that generates an electromagnetic beam of which a first portion of said beam is directed toward said receiver via a first path and of which a second portion of said beam is directed toward said receiver via a second path, wherein a distance said first portion travels via said first path is dependent on any velocity of said apparatus, and wherein a distance said second portion travels via said second path is independent of any velocity of said apparatus;   a phase comparator coupled to said receiver, said phase comparator being arranged to determine a reference phase difference between said first portion traveling via said first path and said second portion traveling via said second path when said apparatus is at a reference velocity, said phase comparator being further arranged to determine a velocity phase difference between said first portion traveling via said first path and said second portion traveling via said second path when said apparatus is at said velocity; and   a computing device arranged to calculate said velocity of said apparatus using at least said reference phase difference, said velocity phase difference, a frequency of said beam, and the speed of light.   
     
     
         8 . The apparatus as recited in  claim 7  wherein said reference velocity is zero relative to the surface of the Earth. 
     
     
         9 . The apparatus as recited in  claim 7  wherein said first path is a straight line. 
     
     
         10 . The apparatus as recited in  claim 7  wherein said first portion traveling via said first path propagates in a propagation medium. 
     
     
         11 . The apparatus as recited in  claim 7  wherein said first path includes a zigzag portion. 
     
     
         12 . The apparatus as recited in  claim 7  wherein said first path includes a solid medium that is longer than the distance between said source and said first receiver. 
     
     
         13 . The apparatus as recited in  claim 7  further comprising:
 a beam splitter that splits said beam from said source into said first portion traveling via said first path and said second portion traveling via said second path. 
 
     
     
         14 . The apparatus as recited in  claim 7  wherein a second receiver is located in physical contact with said source, said apparatus further comprising:
 an electrical conductor that conducts a signal from said second receiver to said phase comparator. 
 
     
     
         15 . A method as recited in  claim 1  wherein a source of said beam, said second path and said receiver are all contained in a bulk material having a refractive index greater than 1. 
     
     
         16 . A method as recited in  claim 1  wherein said second path is a zig-zag path perpendicular to said velocity of said apparatus. 
     
     
         17 . A method as recited in  claim 1  wherein said second path travels through a solid medium which maintains a coherent polarization of said beam. 
     
     
         18 . A method as recited in  claim 17  wherein said second path travels in one or more loops. 
     
     
         19 . A method as recited in  claim 1  wherein said second path travels in one or more loops. 
     
     
         20 . An apparatus as recited in  claim 7  wherein said source, said second path and a second receiver are all contained in a bulk material having a refractive index greater than 1. 
     
     
         21 . An apparatus as recited in  claim 7  wherein said second path is a zig-zag path perpendicular to said velocity of said apparatus. 
     
     
         22 . An apparatus as recited in  claim 7  wherein said second path travels through a solid medium which maintains a coherent polarization of said beam. 
     
     
         23 . A method as recited in  claim 22  wherein said second path travels in one or more loops. 
     
     
         24 . A method as recited in  claim 7  wherein said second path travels in one or more loops. 
     
     
         25 . A method as recited in  claim 1  wherein said beam at said reference velocity is a pulse and wherein said beam at said velocity is a pulse. 
     
     
         26 . An apparatus as recited in  claim 7  wherein said beam at said reference velocity is a pulse and wherein said beam at said velocity is a pulse. 
     
     
         27 . A method as recited in  claim 1  wherein said second path includes fiber optic cable having loops that are spaced apart evenly. 
     
     
         28 . An apparatus as recited in  claim 7  wherein said second path includes fiber optic cable having loops that are spaced apart evenly. 
     
     
         29 . A method as recited in  claim 1  wherein said first and second paths are within solid, transparent material. 
     
     
         30 . A method as recited in  claim 29  wherein said first and second paths are within fiber optic cable. 
     
     
         31 . A method as recited in  claim 1  wherein said receiver includes first and second receivers, wherein said first path ends at said first receiver and wherein said second path ends at said second receiver. 
     
     
         32 . An apparatus as recited in  claim 7  wherein said first and second paths are within solid, transparent material. 
     
     
         33 . An apparatus as recited in  claim 7  wherein said first and second paths are within fiber optic cable. 
     
     
         34 . An apparatus as recited in  claim 7  wherein said receiver includes first and second receivers, wherein said first path ends at said first receiver, wherein said second path ends at said second receiver, and wherein said phase comparator is coupled to both said first and second receivers. 
     
     
         35 . A method as recited in  claim 1  wherein said first path is orientated in the direction of motion of said apparatus and wherein said second path is at least one loop of fiber optic cable. 
     
     
         36 . An apparatus as recited in  claim 7  wherein said first path is orientated in the direction of motion of said apparatus and wherein said second path is at least one loop of fiber optic cable. 
     
     
         37 . A method as recited in  claim 1  wherein a length of said second path is about ten times a length of said first path. 
     
     
         38 . An apparatus as recited in  claim 7  wherein a length of said second path is about ten times a length of said first path.

Join the waitlist — get patent alerts

Track US2017038404A1 — get alerts on status changes and closely related new filings.

We store only your email — no account needed. See our privacy policy.