GB1403358A - Doppler movement detectors - Google Patents

Doppler movement detectors

Info

Publication number
GB1403358A
GB1403358A GB4005171A GB4005171A GB1403358A GB 1403358 A GB1403358 A GB 1403358A GB 4005171 A GB4005171 A GB 4005171A GB 4005171 A GB4005171 A GB 4005171A GB 1403358 A GB1403358 A GB 1403358A
Authority
GB
United Kingdom
Prior art keywords
gate
square wave
doppler
output
aug
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
GB4005171A
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.)
EMI Ltd
Original Assignee
EMI 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 EMI Ltd filed Critical EMI Ltd
Priority to GB4005171A priority Critical patent/GB1403358A/en
Publication of GB1403358A publication Critical patent/GB1403358A/en
Expired legal-status Critical Current

Links

Classifications

    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/50—Systems of measurement based on relative movement of target
    • G01S13/52—Discriminating between fixed and moving objects or between objects moving at different speeds
    • G01S13/56—Discriminating between fixed and moving objects or between objects moving at different speeds for presence detection

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)

Abstract

1403358 Intruder alarms EMI Ltd 29 Aug 1972 [26 Aug 1971] 40051/71 Heading G4N [Also in Division H4] In a Doppler radar or sonar intruder alarm system, the echo signal is combined separately in mixers 5A and 5B with phase quadrature samples of the transmitted signal to give phase quadrature Doppler frequency signals which are processed to give a Doppler frequency pulse train output from either an advance gate 14 or a recede gate 15 according to whether the reflecting object is approaching or receding and said output pulse trains are coupled to a bi-directional counter 16 which triggers an alarm when the resultant count exceeds a threshold N corresponding to a predetermined radial displacement of said object. As shown the Doppler output from the mixer 5A is amplified, filtered and converted to a corresponding square wave by a trigger unit having a predetermined amplitude threshold, the gates 14 and 15 being enabled by the positive half cycles of said square wave and the corresponding square wave signal derived from mixer 5B being differentiated and applied directly to gate 15 and via an inverter to gate 14.
GB4005171A 1971-08-26 1971-08-26 Doppler movement detectors Expired GB1403358A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB4005171A GB1403358A (en) 1971-08-26 1971-08-26 Doppler movement detectors

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4005171A GB1403358A (en) 1971-08-26 1971-08-26 Doppler movement detectors

Publications (1)

Publication Number Publication Date
GB1403358A true GB1403358A (en) 1975-08-28

Family

ID=10412928

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4005171A Expired GB1403358A (en) 1971-08-26 1971-08-26 Doppler movement detectors

Country Status (1)

Country Link
GB (1) GB1403358A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0095300A2 (en) * 1982-05-25 1983-11-30 Plessey Overseas Limited Vehicle mounted Doppler radar system
GB2285358A (en) * 1993-12-28 1995-07-05 Fujitsu Ltd CW homodyne radar

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0095300A2 (en) * 1982-05-25 1983-11-30 Plessey Overseas Limited Vehicle mounted Doppler radar system
EP0095300A3 (en) * 1982-05-25 1984-05-23 Plessey Overseas Limited Vehicle mounted doppler radar system
US4635059A (en) * 1982-05-25 1987-01-06 Plessey Overseas Limited Vehicle mounted Doppler radar system
GB2285358A (en) * 1993-12-28 1995-07-05 Fujitsu Ltd CW homodyne radar
US5506585A (en) * 1993-12-28 1996-04-09 Fujitsu Limited Continuous wave radar effective for preventing collision of mobile object
GB2285358B (en) * 1993-12-28 1998-02-25 Fujitsu Ltd Continual wave radar

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee