US3631486A
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Processing method and commutation system for pulse doppler radar
Assignee: Westinghouse Electric Corp
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Filing: 1969-06-24
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Granted: 1971-12-28
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Expires: 1989-06-24
Abstract
Abstract In a pulse Doppler radar system, a threshold level for target detection is automatically adjusted as a function of clutter and noise. A commutation network for interrogating each of a plurality of Doppler channels simultaneously interrogates channels of adjacent higher and lower frequencies for deriving a threshold signal comprising an average or normalized detection threshold for the interrogated channel, for all channels. The commutation system also provides for enhancement of the accuracy of velocity measurement of a given number of Doppler channels by interpolating between consecutive pairs of channels.
Inventors
- 👤 Roland A Anders
- 👤 David E Callahan
- 👤 F Stewart Myers Jr
- 👤 James M Saboe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:25
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/58; G01S13/585
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
183 words
In a pulse Doppler radar system having a plurality of filter channels of predetermined bandwidths and different, successive ranges of frequencies to which received signals are applied and each of which produces an output responsive to the received signal content in the corresponding frequency range, a method for processing the filter channel outputs comprising: applying received signals to said plurality of filter channels, interrogating said filter channels in succession to define a plurality of signal sources throughout a predetermined range of frequencies to be examined for the detection of target signals, selecting filter channels having outputs of predetermined frequency relationship to said signal sources to define a plurality of reference sources corresponding to the plurality of signal sources, interrogating said corresponding reference source filter channels in simultaneous succession with the interrogation of said signal source filter channels, and comparing the values of the signal sources with the values of the corresponding reference sources in each successive simultaneous interrogation to detect as target signals all signal sources having values exceeding the values of the corresponding reference sources in accordance with a predetermined relationship therebetween.
Claim 2
Dependent Claim
183 words
In a pulse Doppler radar system having a plurality of filter channels of predetermined bandwidths and different, successive ranges of frequencies to which received signals are applied and each of which produces an output responsive to the received signal content in the corresponding frequency range, a method for processing the filter channel outputs comprising: applying received signals to said plurality of filter channels, interrogating said filter channels in succession to define a plurality of signal sources throughout a predetermined range of frequencies to be examined for the detection of target signals, selecting filter channels having outputs of predetermined frequency relationship to said signal sources to define a plurality of reference sources corresponding to the plurality of signal sources, interrogating said corresponding reference source filter channels in simultaneous succession with the interrogation of said signal source filter channels, and comparing the values of the signal sources with the values of the corresponding reference sources in each successive simultaneous interrogation to detect as target signals all signal sources having values exceeding the values of the corresponding reference sources in accordance with a predetermined relationship therebetween.
Claim 3
Dependent Claim
67 words
A processing method as recited in claim 1, further comprising: interrogating said filter channels in an alternate succession of individual, successive filter channels and respectively next successive adjacent pairs of filter channels to define as the plurality of signal sources the alternate succession of outputs of individual, successive filter channels and interpolated filter channel outputs comprising the average of the outputs of adjacent pairs of filter channels.
Claim 4
Dependent Claim
59 words
A processing method as recited in claim 1 further comprising: selecting as reference sources for each signal source, filter channels of higher and lower frequencies than that of the corresponding signal source, and comparing the value of each signal source with the average value of the corresponding higher and lower frequency reference sources, for each signal source in succession.
Claim 5
Dependent Claim
31 words
A processing method as recited in claim 3 comprising: selecting as reference sources corresponding to each signal source the two successively higher frequency and the two successively lower frequency filter channels.
Claim 6
Dependent Claim
66 words
A processing method as recited in claim 3 comprising: interrogating said filter channels in an alternate succession of individual, successive filter channels and respectively next successive adjacent pairs of filter channels to define as the plurality of signal sources the alternate succession of outputs of individual, successive filter channels and interpolated filter channel outputs comprising the average of the outputs of adjacent pairs of filter channels.
Claim 7
Dependent Claim
179 words
In a pulse Doppler radar system having a plurality of filter channels of predetermined bandwidths in different, successive ranges of frequencies to which received signals are applied and each of which produces an output responsive to the received signal content in the corresponding frequency range, a commutation and signal processing system comprising: means for interrogating said filter channels selectively and in succession to derive from the outputs thereof a plurality of signal sources over a predetermined range of frequencies to be examined for the detection of target signals, means for interrogating selected ones of said filter channels to define a plurality of reference sources corresponding to and of predetermined frequency relationship to each of said signal sources, means for simultaneously actuating said signal sources and said corresponding reference sources in succession, and means for comparing the values of the signal sources with the values of the corresponding reference sources in each successive simultaneous interrogation to detect as target signals all signal sources having values exceeding the values of the corresponding reference sources in accordance with a predetermined relationship therebetween.
Claim 8
Dependent Claim
179 words
In a pulse Doppler radar system having a plurality of filter channels of predetermined bandwidths in different, successive ranges of frequencies to which received signals are applied and each of which produces an output responsive to the received signal content in the corresponding frequency range, a commutation and signal processing system comprising: means for interrogating said filter channels selectively and in succession to derive from the outputs thereof a plurality of signal sources over a predetermined range of frequencies to be examined for the detection of target signals, means for interrogating selected ones of said filter channels to define a plurality of reference sources corresponding to and of predetermined frequency relationship to each of said signal sources, means for simultaneously actuating said signal sources and said corresponding reference sources in succession, and means for comparing the values of the signal sources with the values of the corresponding reference sources in each successive simultaneous interrogation to detect as target signals all signal sources having values exceeding the values of the corresponding reference sources in accordance with a predetermined relationship therebetween.
Claim 9
Dependent Claim
99 words
A system as recited in claim 6 wherein: said interrogating means for deriving said signal sources comprises a first plurality of switches respectively associated with the plurality of filter channels to be interrogated as signal sources and selectively actuatable by said actuating means for interrogating the respectively associated filter channels as signal sources, and said interrogating means for defining said reference sources comprises a second plurality of switches respectively associated with the plurality of filter channels to be interrogated as reference sources and selectively actuatable by said actuating means for interrogating the respectively associated filter channels as reference sources.
Claim 10
Dependent Claim
56 words
A system as recited in claim 7 wherein said comparing means includes: signal source scaling means connected in common to said first plurality of switches, reference source scaling means connected in common to said second plurality of switches, and a comparison circuit connected to said signal source scaling means and to said reference source scaling means.
Claim 11
Dependent Claim
94 words
A system as recited in claim 7 wherein: said interrogating means for defining said reference sources provides for interrogation of selected higher and lower frequency channels defining higher and lower frequency reference sources corresponding to each of said signal sources, and said second plurality of switches includes a first set thereof connected to said filter channels and selectively actuatable for defining higher frequency reference sources and a second set thereof connected to said filter channels and selectively actuatable for defining lower frequency reference sources respectively corresponding to each of said plurality of signal sources.
Claim 12
Dependent Claim
44 words
A system as recited in claim 9 wherein: said interrogation means for defining said reference sources provides for interrogation of the next two successively higher and the next two successively lower frequency channels for defining corresponding reference sources for each of said signal sources.
Claim 13
Dependent Claim
85 words
A system as recited in claim 7 wherein: said actuating means including means to selectively actuate said first plurality of switches in an alternate succession of individual switches associated with successive individual filter channels and pairs of switches associated with respectively next successive pairs of filter channels to define as the plurality of signal sources the alternate succession of outputs of the individual, successive filter channels and interpolated filter channel outputs comprising the average of the outputs of the next successive pairs of filter channels.
Claim 14
Dependent Claim
116 words
A system as recited in claim 6 wherein said actuating means comprises: first and second shift register means each having a plurality of stages with the stages of said first shift register respectively associated with odd numbered ones of said plurality of filter channels and the stages of said second shift register respectively associated with even numbered ones of said plurality of filter channels, said first and second shift registers being responsive to opposite phases of a shift register clock pulse train for switching each stage between set and reset states at a rate one-half the rate of interrogation of successive signal sources, cyclically and in succession for the plurality of stages of each shift register.
Claim 15
Dependent Claim
62 words
A system as recited in claim 12 wherein: each stage of said first shift register, when set, provides for interrogation of a reference source filter channel next preceding a simultaneously interrogated signal source filter channel, and each stage of said second shift register, when set, provides for interrogating a reference source filter channel next succeeding a simultaneously interrogated signal source filter channel.
Claim 16
Dependent Claim
43 words
A system as recited in claim 13 wherein each stage of each of said first and second shift register means, when set, provides for interrogation of two reference source filter channels next succeeding and next preceding, respectively, simultaneously interrogated signal source filter channels.
Claim 17
Dependent Claim
91 words
A system as recited in claim 6 wherein said actuating means comprises: shift register means having a plurality of stages respectively corresponding to the plurality of filter channels and adapted to be switched to a set state in successive pairs thereof, each stage being maintained in a set state for four equal intervals, and gating means associated with and responsive to each of said shift register stages and enabled during the first three successive intervals of the set states thereof for generating interrogation signals for interrogating the respectively corresponding filter channels.
Claim 18
Dependent Claim
110 words
A system as recited in claim 15 wherein: said gating means includes a plurality of gates respectively associated with said shift register stages, and each of said gates is individually enabled during the second of said three interrogation intervals and pairs of adjacent ones of said gates are simultaneously enabled during the first and third of said interrogation intervals for interrogating said plurality of filter channels in an alternate succession of individual and successive pairs thereof to define as the plurality of signal sources the alternate succession of outputs of individual, successive filter channels and interpolated outputs comprising the average of the outputs of successive, adjacent pairs of filter channels.
Claim 19
Dependent Claim
103 words
A system as recited in claim 15 wherein said interrogation means for defining said reference sources includes: means respectively associated with said stages of said shift register and responsive to the set states thereof for interrogating a predetermined lower frequency filter channel as a lower frequency reference source simultaneously with the interrogation of a signal source filter channel respectively associated therewith, and gating means respectively associated with said signal source gating means and responsive to the signal source interrogation signals generated thereby for interrogating a predetermined higher frequency filter channel as a higher frequency reference source for each interrogated signal source filter channel.
References Cited (Backward Citations)
US3140486A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |