US3728728A
Expired / Lapsed
US
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Method and apparatus for automatic transponder delay correction
Assignee: International Standard Electric Corp
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Filing: 1970-06-05
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Granted: 1973-04-17
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Expires: 1990-06-05
Abstract
Abstract A method and apparatus is provided for determining the varying delays in a pulse interrogation system wherein a reply pulse is transmitted after a predetermined time following reception of an interrogation pulse. Transmitter and receiver delays are measured in a ring counter with the aid of a measuring pulse taken from the transmitter. This measured delay is subtracted from the predetermined time between the next pulse received and the following transmitted pulse thereby providing automatic transponder delay correction.
Inventors
- 👤 H Vogel
- 👤 H Kleiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:25
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/78; G01S13/785; G01S13/787
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
113 words
An improved method of determining the varying delays in the receiver and transmitter of a pulse interrogation system of the type wherein a pulse is transmitted from a ground station after a predetermined time following the reception of a pulse, and wherein the receiver is switched off during transmission, particularly for use in precision distance measuring in radio navigation, wherein the improvement comprises: measuring the delay in the transmitter stages; generating a measuring pulse at the transmitter at the start of transmission; measuring the delay in the receiver stage; and subtracting from the predetermined time between the next received pulse and the following transmitted pulse, the sum of the transmitter and receiver delays.
Claim 2
Dependent Claim
113 words
An improved method of determining the varying delays in the receiver and transmitter of a pulse interrogation system of the type wherein a pulse is transmitted from a ground station after a predetermined time following the reception of a pulse, and wherein the receiver is switched off during transmission, particularly for use in precision distance measuring in radio navigation, wherein the improvement comprises: measuring the delay in the transmitter stages; generating a measuring pulse at the transmitter at the start of transmission; measuring the delay in the receiver stage; and subtracting from the predetermined time between the next received pulse and the following transmitted pulse, the sum of the transmitter and receiver delays.
Claim 3
Dependent Claim
24 words
A method according to claim 1, wherein generating said measuring pulse includes coupling out a part of the transmitting energy as a measuring pulse.
Claim 4
Dependent Claim
63 words
A method according to claim 2, wherein measuring the delay in the receiver stage includes the steps of: passing said measuring pulse through at least part of the receiver stage; generating a trigger pulse from said measuring pulse; and stopping a ring counter with said trigger pulse, said ring counter defining said predetermined time by releasing a transmitting pulse at each zero passage.
Claim 5
Dependent Claim
28 words
A method according to claim 3, wherein the step of subtracting includes triggering said ring counter to count from the preset value upon reception of the next pulse.
Claim 6
Independent Claim
176 words
A device for improving the distance measurement accuracy of a radio navigation system which includes fixed and mobile transmitter-receiver arrangements and in which distance measurement is effected as a function of measured time delay between a coded interrogation pulse group comprising at least one pulse, transmitted from said mobile transmitter, and reception by said mobile receiver of a reply pulse group from said fixed transmitter, comprising: first means within said fixed transmitter-receiver arrangement to initiate said transmitted reply pulse group after a predetermined time delay from reception of said interrogation pulse group at said fixed receiver; second means within said fixed transmitter-receiver for developing a measuring pulse substantially at the time of occurrence of each of said transmitted reply pulse groups; and control means for directing said Measuring pulse through at least a portion of the circuits of said fixed receiver and thereafter to said first means at a time when operation of said fixed receiver is not required for receiving interrogation pulses, in a manner to control said predetermined time delay to a calibration value.
Claim 7
Independent Claim
176 words
A device for improving the distance measurement accuracy of a radio navigation system which includes fixed and mobile transmitter-receiver arrangements and in which distance measurement is effected as a function of measured time delay between a coded interrogation pulse group comprising at least one pulse, transmitted from said mobile transmitter, and reception by said mobile receiver of a reply pulse group from said fixed transmitter, comprising: first means within said fixed transmitter-receiver arrangement to initiate said transmitted reply pulse group after a predetermined time delay from reception of said interrogation pulse group at said fixed receiver; second means within said fixed transmitter-receiver for developing a measuring pulse substantially at the time of occurrence of each of said transmitted reply pulse groups; and control means for directing said Measuring pulse through at least a portion of the circuits of said fixed receiver and thereafter to said first means at a time when operation of said fixed receiver is not required for receiving interrogation pulses, in a manner to control said predetermined time delay to a calibration value.
Claim 8
Dependent Claim
84 words
Apparatus according to claim 5 in which said measuring pulses are derived from a portion of the energy of said transmitted reply pulses, said receiver includes a mixer, an intermediate frequency amplifier and decoder circuits for unambiguously recognizing said coded interrogation pulse groups including means to produce corresponding output triggers, and said logic control means are adapted to direct said measuring pulse first through said decoder circuits, next through said intermediate frequency amplifier, and then through said output trigger means to said first means.
Claim 9
Dependent Claim
69 words
Apparatus according to claim 6 in which said first means includes third means comprising a clock-driven, counting, delay-determing device responsive to said output trigger corresponding to said measuring pulse to terminate its count, said third means thereby assuming a delay value automatically applied from reception of the next interrogation pulse group to apply said predetermined time delay to generation of the corresponding reply pulse group by said fixed transmitter.
Claim 10
Dependent Claim
98 words
Apparatus according to claim 7 in which said third means comprises a ring counter adapted to count under the control of a clock pulse train and to terminate said count at the time of application of said measuring pulse, and to provide a transmitter trigger after completion of the count in response to the next interrogation pulse group through said fixed receiver, thereby to provide implicit subtraction of the delays of the loop including said fixed transmitter and receiver from the predetermined time between the next following received interrogation pulse group and the correspondingly generated fixed transmitter reply.
Claim 11
Dependent Claim
27 words
Apparatus according to claim 6 including a modulator connected to convert said measuring pulse to the IF domain before it is passed through said intermediate frequency amplifier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |