US3787846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Close-in ranger system
Assignee: United States Department of the Navy
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Filing: 1972-08-10
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Granted: 1974-01-22
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Expires: 1992-08-10
Abstract
Abstract A range measuring system wherein a transponder at a remote location is interrogated by coded signals from a base location. If the interrogation is correctly coded the transponder replies. Receipt of a correct reply interrupts the generation of a ramp voltage at the base location. The ramp voltage is measured to determine the range from the base to the transponder. Novel circuitry including a ramp current generator, selectively variable impedance input range switch means, a selectively variable initial voltage ramp set range switch means, shaper gate means and a timer with pulse repetition frequency gate means, is provided to obtain superior accuracy in range measurements.
Inventors
- 👤 W Bishop
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:58
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/78; G01S13/785; G01S13/787
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
196 words
In a range measuring system, the improvement comprising: a. a ranger and signal selector means, b. an interrogator connected to said ranger means to receive an interrogation command signal and to transmit time-coded radio frequency pulses, c. a transponder responsive to said time-coded pulses to transmit a returning radio frequency pulse, d. a receiver for receiving said radio frequency pulse and developing a video pulse output, e. said ranger including a ramp capacitor, a ramp current generator for charging said ramp capacitor, ramp switch means connecting said ramp generator and capacitor, and a timing circuit means for producing said itnerrogation command and for actuating said ramp switch means to begin charging said ramp capacitor, f. said signal selector means being connected to said receiver and to said timing circuit means to interrupt the charging of said ramp capacitor when a video signal output is developed from said receiver, g. said signal selector means including a main AND gate, shaper means for excluding noise spike signals and time and pulse repetition frequency gate means for excluding interference signals, said shaper and pulse repetition frequency gatE being connected through said main AND gate to said timing circuit means.
Claim 2
Dependent Claim
196 words
In a range measuring system, the improvement comprising: a. a ranger and signal selector means, b. an interrogator connected to said ranger means to receive an interrogation command signal and to transmit time-coded radio frequency pulses, c. a transponder responsive to said time-coded pulses to transmit a returning radio frequency pulse, d. a receiver for receiving said radio frequency pulse and developing a video pulse output, e. said ranger including a ramp capacitor, a ramp current generator for charging said ramp capacitor, ramp switch means connecting said ramp generator and capacitor, and a timing circuit means for producing said itnerrogation command and for actuating said ramp switch means to begin charging said ramp capacitor, f. said signal selector means being connected to said receiver and to said timing circuit means to interrupt the charging of said ramp capacitor when a video signal output is developed from said receiver, g. said signal selector means including a main AND gate, shaper means for excluding noise spike signals and time and pulse repetition frequency gate means for excluding interference signals, said shaper and pulse repetition frequency gatE being connected through said main AND gate to said timing circuit means.
Claim 3
Dependent Claim
85 words
Apparatus according to claim 1, said timing circuit means including: a. a clock having frequency adjustment RC network means and an output pulse width adjustment RC network means, b. a clock flip-flop circuit, c. a ramp flip-flop connected to actuate said ramp switch, and d. an adjustable delay circuit means connected to receive a pulse from said interrogator and to pass a delayed pulse to said ramp flip-flop, said delay being set to match the combined inherent fixed delays of said transponder and receiver circuits.
Claim 4
Dependent Claim
97 words
Apparatus according to claim 2 including: a. a range switch for connecting said ramp current generator to a source of voltage and having selective impedance means for varying the sensitivity of said ranger circuit for application to different range measurements, b. a normally closed dump switch, c. an additional range switch with additional selective impedance means, d. said dump switch, range switch and additional impedance means being connected in series between opposite sides of said ramp capacitor to vary the initial charged condition thereof and thereby vary sensitivity of said range circuit to obtain improved range measurements.
Claim 5
Dependent Claim
72 words
Apparatus according to claim 3, said range circuit including a range meter, an operational amplifier, a memory capacitor connected to sample said ramp capacitor voltage via said operational amplifier and hold the range voltage on said meter between samples and boxcar delay, pulser and switch means connected to said timer and to said ramp and memory capacitor to time the sampling of said ramp capacitor allowing setting time for said operational amplifier.
Claim 6
Dependent Claim
45 words
Apparatus according to claim 1, including: a range switch for connecting said ramp current generator to a source of voltage and having selective impedance means for varying the sensitivity of said ranger circuit for application to different range measurements and thereby obtain improved range measurements.
Claim 7
Dependent Claim
63 words
Apparatus according to claim 5 including: a. a normally closed dump switch, b. an additional range switch with additional selective impedance means, c. said dump switch, range switch and additional impedance means being connected in series between opposite sides of said ramp capacitor to vary the initial charged condition thereof and thereby vary sensitivity of said range circuit to obtain improved range measurements.
Claim 8
Dependent Claim
63 words
Apparatus according to claim 1, including: a. a normally closed dump switch, b. an additional range switch with additional selective impedance means, c. said dump switch, range switch and additional impedance means being connected in series between opposite sides of said ramp capacitor to vary the initial charged condition thereof and thereby vary sensitivity of said range circuit to obtain improved range measurements.
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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |