GB1333546A - Radio interferometer - Google Patents

Radio interferometer

Info

Publication number
GB1333546A
GB1333546A GB1333546DA GB1333546A GB 1333546 A GB1333546 A GB 1333546A GB 1333546D A GB1333546D A GB 1333546DA GB 1333546 A GB1333546 A GB 1333546A
Authority
GB
United Kingdom
Prior art keywords
phase
discriminators
degrees
ground
pairs
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
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 Components Ltd
Original Assignee
Mullard 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 Mullard Ltd filed Critical Mullard Ltd
Publication of GB1333546A publication Critical patent/GB1333546A/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
    • G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received
    • G01S3/02—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using radio waves
    • G01S3/14—Systems for determining direction or deviation from predetermined direction
    • G01S3/46—Systems for determining direction or deviation from predetermined direction using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
    • G01S3/48—Systems for determining direction or deviation from predetermined direction using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems the waves arriving at the antennas being continuous or intermittent and the phase difference of signals derived therefrom being measured

Abstract

1333546 Radio direction-finders MULLARD Ltd 10 May 1972 [2 June 1971] 21832/72 Heading H4D [Also in Division G4] In a radio direction-finder there is a vertically extending rectilinear array which includes a plurality of pairs of equally spaced aerial elements, phase discriminator means to derive from each pair of elements a measure of elevation angle # of incoming waves, and means to derive the average of the measurements. The invention reduces errors due to ground-reflection. In a microwave embodiment the aerial elements at the L.H.S. have a spacing 16d (d=6À5 cms., frequency 5 GHz) for each of pairs 16/3 and 3, 16/C and C, 16/2 and 2, and 16/4 and 4; element 3 is spaced near to ground e.g. at a height of 12 cms. Items B are superheterodyne receivers all supplied in identical phase from a common local oscillator not shown. Discriminators D measure phase differences at an I.F., e.g. 40 Me/s., digitally, e.g. as described in Specification 1,191,831. Phases derived from the four widest spaced pairs are converted to four bit binary code in converters C and are averaged by addition and scale shift division in device A. Logic L resolves ambiguity and provides a ten bit binary measure of elevation angle. Phase-measuring, Fig. 4.-A transmission line T is (3#)/8 long and has tappings E, F, G, H spaced apart by #/8; outputs from squarelaw detectors J are compared in subtractors S to yield the outputs as shown (i.e. phase digitized to within 45 degrees) for the indicated inputs to the line. Modification to Fig. 3.-The receivers B do not feed directly into discriminators D but the output from each receiver is applied to a phase modulator (PM, Fig. 5, not shown) consisting of a voltage-dependent resistor/capacitor phase shifter and a triangular 500 Hz waveform is applied thereto to effect a phase excursion equivalent to the digital interval of the phase discriminators (22¢ degrees). It is stated that by integrating over a number of pulses, phase measurement accuracy is improved. In an experiment two aircraft could be separated in elevation when the angle between them from the ground was greater than (0À1 degrees sec#).
GB1333546D 1972-05-10 1972-05-10 Radio interferometer Expired GB1333546A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2183272 1972-05-10

Publications (1)

Publication Number Publication Date
GB1333546A true GB1333546A (en) 1973-10-10

Family

ID=10169566

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1333546D Expired GB1333546A (en) 1972-05-10 1972-05-10 Radio interferometer

Country Status (1)

Country Link
GB (1) GB1333546A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5621410A (en) * 1992-11-05 1997-04-15 New Mexico Tech Research Foundation Remote prediction of lightning hazards
GB2309842A (en) * 1995-03-07 1997-08-06 Stephen Joseph Robinson Radio direction finder and beacon
US5812091A (en) * 1996-02-01 1998-09-22 Robinson; Stephen J. Radio interferometric antenna for angle coding

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5621410A (en) * 1992-11-05 1997-04-15 New Mexico Tech Research Foundation Remote prediction of lightning hazards
GB2309842A (en) * 1995-03-07 1997-08-06 Stephen Joseph Robinson Radio direction finder and beacon
GB2309842B (en) * 1995-03-07 1997-09-17 Stephen Joseph Robinson Radio interferometric antenna for angle coding
US5812091A (en) * 1996-02-01 1998-09-22 Robinson; Stephen J. Radio interferometric antenna for angle coding

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Legal Events

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