GB1308957A - Methods and apparatus for determining the distance of an object - Google Patents

Methods and apparatus for determining the distance of an object

Info

Publication number
GB1308957A
GB1308957A GB1348470A GB1348470A GB1308957A GB 1308957 A GB1308957 A GB 1308957A GB 1348470 A GB1348470 A GB 1348470A GB 1348470 A GB1348470 A GB 1348470A GB 1308957 A GB1308957 A GB 1308957A
Authority
GB
United Kingdom
Prior art keywords
light
incident
frequency
varied
beams
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB1348470A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Philips Electronics UK Ltd
Original Assignee
Philips Electronic and Associated Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Philips Electronic and Associated Industries Ltd filed Critical Philips Electronic and Associated Industries Ltd
Publication of GB1308957A publication Critical patent/GB1308957A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
    • G01B9/02055—Reduction or prevention of errors; Testing; Calibration
    • G01B9/02075—Reduction or prevention of errors; Testing; Calibration of particular errors
    • G01B9/02078—Caused by ambiguity
    • G01B9/02079—Quadrature detection, i.e. detecting relatively phase-shifted signals
    • G01B9/02081—Quadrature detection, i.e. detecting relatively phase-shifted signals simultaneous quadrature detection, e.g. by spatial phase shifting
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • G01S17/32—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
    • G01S17/34—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
    • G01B2290/70—Using polarization in the interferometer

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Instruments For Measurement Of Length By Optical Means (AREA)

Abstract

1308957 Measuring displacements PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 20 March 1970 [25 March 1969] 13484/70 Heading G4H If in a Michelson type interferometer the frequency or other parameter of the incident light is varied about an average value, the number of zero crossings of the intensity during a fixed time period is proportional to the displacement of one mirror with the respect to the other, and to the modulating frequency. Thus by counting the number of zero crossings the distance between the two mirrors may be measured. Light incident from a source 1 on a Michelson type interferometer passes via beam splitter 3, through quarter-wave plates 21 and 28. In this way the light passing through 28 comprises two beams of circularly polarized light which combine to form a single beam of linearly polarized light whose plane polarization is rotated with respect to that of the incident light, the angle of rotation being proportional to the displacement of the mirror 7. The light may be monitored by means of polarizer 23 and photodetechtor 25 whose output feeds into counter 26, and polarizer 24 whose angle is at 90 degrees to that of 23, and photo-electric detector 27 which also feeds into counter 26. The light incident at 1 may comprise two linearly polarized beams with planes of polarization at 90 degrees. The frequency of the incident light may be varied, or the frequencies of the two incident beams may be different, and the difference frequency may be varied.
GB1348470A 1969-03-25 1970-03-20 Methods and apparatus for determining the distance of an object Expired GB1308957A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL6904621A NL6904621A (en) 1969-03-25 1969-03-25

Publications (1)

Publication Number Publication Date
GB1308957A true GB1308957A (en) 1973-03-07

Family

ID=19806529

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1348470A Expired GB1308957A (en) 1969-03-25 1970-03-20 Methods and apparatus for determining the distance of an object

Country Status (5)

Country Link
BE (1) BE747836A (en)
CH (1) CH520319A (en)
FR (1) FR2035878B1 (en)
GB (1) GB1308957A (en)
NL (1) NL6904621A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2129124A (en) * 1982-10-16 1984-05-10 Ferranti Plc Aligning mask with body
GB2256480A (en) * 1991-06-05 1992-12-09 Marconi Gec Ltd Optical sensor

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2468099A1 (en) * 1979-10-17 1981-04-30 Anvar METHOD AND APPARATUS FOR LASER INTERFEROMETRY WITH TWO WAVE LENGTHS
DD201191B1 (en) * 1981-09-24 1987-07-15 Ilmenau Tech Hochschule KIPPINVARIANT INTERFEROMETER WITH LEVELS MIRROR
GB2127960B (en) * 1982-09-29 1985-12-11 British Aerospace Ring laser gyroscope readout arrangements

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1086053A (en) * 1953-07-02 1955-02-09 Csf Improvements to frequency-modulated telemetry systems
US3366954A (en) * 1966-11-04 1968-01-30 Air Force Usa Spectrographical range finder
AU409380B2 (en) * 1966-12-06 1971-01-07 Improvements in or relating to optical mixing devices

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2129124A (en) * 1982-10-16 1984-05-10 Ferranti Plc Aligning mask with body
GB2256480A (en) * 1991-06-05 1992-12-09 Marconi Gec Ltd Optical sensor
GB2256480B (en) * 1991-06-05 1995-02-01 Marconi Gec Ltd Improvements to optical sensors

Also Published As

Publication number Publication date
CH520319A (en) 1972-03-15
DE2012946A1 (en) 1970-10-01
NL6904621A (en) 1970-09-29
DE2012946B2 (en) 1975-07-24
FR2035878B1 (en) 1974-09-20
BE747836A (en) 1970-09-23
FR2035878A1 (en) 1970-12-24

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee