GB1490751A - Doppler radar - Google Patents

Doppler radar

Info

Publication number
GB1490751A
GB1490751A GB1205/75A GB120575A GB1490751A GB 1490751 A GB1490751 A GB 1490751A GB 1205/75 A GB1205/75 A GB 1205/75A GB 120575 A GB120575 A GB 120575A GB 1490751 A GB1490751 A GB 1490751A
Authority
GB
United Kingdom
Prior art keywords
signal
amplitude
comparison signal
quadrature
switch
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
GB1205/75A
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.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
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 Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Publication of GB1490751A publication Critical patent/GB1490751A/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
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/28—Details of pulse systems
    • G01S7/285—Receivers
    • G01S7/292—Extracting wanted echo-signals
    • G01S7/2923—Extracting wanted echo-signals based on data belonging to a number of consecutive radar periods
    • G01S7/2928—Random or non-synchronous interference pulse cancellers

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

1490751 Radar TELEFONAKTTEBOLAGET L M ERICSSON 10 Jan 1975 [15 Jan 1974] 1205/75 Heading H4D In a pulse Doppler radar, of the type wherein the echo signals are quadrature phase detected to give quadrature signals i, q. circuitry to stop large amplitude interference being passed to further processing circuitry, comprises an amplitude former 7 receiving the quadrature signals and producing a signal (comparison signal) representing the amplitude of the echo signal, and a comparator 8 comparing the 'comparison signal' instantly occurring with that which was produced from a previous echo period and causing the operation of switches 4, 4<SP>1</SP> such that the instant signal is blocked, when the instant comparison signal is significantly larger than the previous comparison signal. The digital quadrature signal i, is first filtered at 1, and then passed to a circuit 4, 5, 6 comprising the twoway switch 4a, one p.r.p. delay 5 and an adder 6 which gives (with switch 4 in the position shown) signal i 1 , being the sum of the instant quadrature signal and that of the previous p.r.p., which sum signal i 1 used for the amplitude former 7 is freer from ground echo interference. The output from comparator 8 switches over switch 4 and also a switch 9 such that with interference being received, the comparison signal which is tapped to the upper input of the comparator is continuously the last received non-interference or low comparison signal. Likewise the provision of delay 5 and the closed loop formed by switch 4 ensures that it is the last received low quadrature signal which is continuously fed to the processing circuits. The amplitude of the instant comparison signal may be monitored in a threshold detector 10 to provide an output signal which, together with the comparator output, enables an AND gate 12. The amplitude former may perform either of the calculations:
GB1205/75A 1974-01-15 1975-01-10 Doppler radar Expired GB1490751A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE7400484A SE371299B (en) 1974-01-15 1974-01-15

Publications (1)

Publication Number Publication Date
GB1490751A true GB1490751A (en) 1977-11-02

Family

ID=20319913

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1205/75A Expired GB1490751A (en) 1974-01-15 1975-01-10 Doppler radar

Country Status (8)

Country Link
AT (1) AT347506B (en)
CH (1) CH578182A5 (en)
DK (1) DK137408B (en)
GB (1) GB1490751A (en)
IT (1) IT1028379B (en)
NL (1) NL7500466A (en)
NO (1) NO134640C (en)
SE (1) SE371299B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0126032A2 (en) * 1983-05-04 1984-11-21 SELENIA INDUSTRIE ELETTRONICHE ASSOCIATE S.p.A. Device for the identification and suppression of unwanted second trace echoes in radar systems
WO2013051944A1 (en) * 2011-10-07 2013-04-11 3D-Radar As Adaptive interference suppression for georadar
EP2743722A1 (en) * 2012-12-14 2014-06-18 BAE Systems PLC Mitigation of anomalous propagation effects in radar
WO2014091230A1 (en) * 2012-12-14 2014-06-19 Bae Systems Plc Mitigation of anomalous propagation effects in radar

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0126032A2 (en) * 1983-05-04 1984-11-21 SELENIA INDUSTRIE ELETTRONICHE ASSOCIATE S.p.A. Device for the identification and suppression of unwanted second trace echoes in radar systems
EP0126032A3 (en) * 1983-05-04 1987-05-27 Selenia Industrie Elettroniche Associate S.P.A. Device for the identification and suppression of unwanted second trace echoes in radar systems
WO2013051944A1 (en) * 2011-10-07 2013-04-11 3D-Radar As Adaptive interference suppression for georadar
CN103959087A (en) * 2011-10-07 2014-07-30 3D雷达公司 Adaptive interference suppression for georadar
CN103959087B (en) * 2011-10-07 2016-12-14 3D雷达公司 The adaptive interference mitigation of GPR
EP2743722A1 (en) * 2012-12-14 2014-06-18 BAE Systems PLC Mitigation of anomalous propagation effects in radar
WO2014091230A1 (en) * 2012-12-14 2014-06-19 Bae Systems Plc Mitigation of anomalous propagation effects in radar
US9810773B2 (en) 2012-12-14 2017-11-07 Bae Systems Plc Mitigation of anomalous propagation effects in radar

Also Published As

Publication number Publication date
NO134640B (en) 1976-08-09
CH578182A5 (en) 1976-07-30
IT1028379B (en) 1979-01-30
DE2500877B2 (en) 1977-07-07
SE371299B (en) 1974-11-11
DE2500877A1 (en) 1975-07-24
DK7075A (en) 1975-09-15
DK137408C (en) 1978-08-07
ATA23575A (en) 1978-05-15
NO750102L (en) 1975-08-11
NO134640C (en) 1976-11-17
DK137408B (en) 1978-02-27
NL7500466A (en) 1975-07-17
AT347506B (en) 1978-12-27

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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