US4106019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Range resolving doppler radar system
Assignee: Raytheon Co
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Filing: 1972-10-05
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Granted: 1978-08-08
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Expires: 1992-10-05
Abstract
Abstract A system for measuring unambiguous target range for targets at high velocities in which target range and doppler frequency data from three sequential transmission dwells of radar returns are stored, each dwell having a different pulse repetition frequency (PRF). The dwell storage unit which includes three sets of dynamic registers is loaded and unloaded serially with respect to range and supplied to a 17 path doppler frequency correlator. After the three dwell storage registers have been loaded with a basic PRF plus jitter, the range interval unfolding is performed by a recirculation process in each of the registers. During recirculation the data is applied to a correlation unit, the purpose of which is to insure that the velocity of the target satisfies a 17 path algorithm across three adjacent dwells in at least one of five range azimuth profiles or paths. Because the same target velocity may cause outputs in adjacent doppler filters due to PRF jitter, the correlation utilizes a criteria that for all three possible PRF sequences the filter numbers across the three range bins and paths must be within one of each other. As the filter correlation function is capable of multiple path selection the filter path outputs are priority selected to produce a valid target. The final output from the system is a verification that the data in the three range bins of interest satisfies the seventeen path correlation algorithm formed of three dwells and three adjacent range bins with a possible PRF jitter of one filter in each range bin.
Inventors
- 👤 Thomas F. Alexander
- 👤 Gary J. Griff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:31
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/28; G01S7/285; G01S7/292; G01S7/2923; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/10; G01S13/106
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
143 words
A range determining system responsive to a doppler filter bank having a plurality of doppler filters, said system receiving radar transmission signals for a plurality of dwells over a plurality of range bins, said filter bank providing a filter number signal when a target return signal occurs in a doppler filter, each filter number signal identifying a doppler filter of said bank comprising: first, second and third storage registers responsive to the doppler filters to store the filter number signals in each range bin for three radar dwells; recirculating control means coupled to said storage registers for controlling said registers to recirculate the stored filter number signals in said first, second and third registers to unfold target information; and correlator means having a plurality of correlators responsive to said stored filter number signals in said storage registers for detecting an unfolded target signal.
Claim 2
Dependent Claim
143 words
A range determining system responsive to a doppler filter bank having a plurality of doppler filters, said system receiving radar transmission signals for a plurality of dwells over a plurality of range bins, said filter bank providing a filter number signal when a target return signal occurs in a doppler filter, each filter number signal identifying a doppler filter of said bank comprising: first, second and third storage registers responsive to the doppler filters to store the filter number signals in each range bin for three radar dwells; recirculating control means coupled to said storage registers for controlling said registers to recirculate the stored filter number signals in said first, second and third registers to unfold target information; and correlator means having a plurality of correlators responsive to said stored filter number signals in said storage registers for detecting an unfolded target signal.
Claim 3
Dependent Claim
50 words
The system of claim 1 in which said system includes means to transmit a plurality of pulses for each dwell, each with a different pulse repetition frequency repetitive on a modulo 3 basis and in which said recirculating control means includes means to control the length of said storage registers.
Claim 4
Dependent Claim
54 words
The system of claim 1 in which the doppler filter number signals from each dwell are transferred to said first register and further including transfer control means coupled to said storage registers to transfer the filter number signals derived from each dwell between said first, second and third storage registers, during each dwell period.
Claim 5
Dependent Claim
43 words
The system of claim 3 in which said correlator means includes means for providing a plurality of range-ozimuth paths for a selected number of adjacent dwells and means for detecting a target when a filter number signal occurs in one of said paths.
Claim 6
Dependent Claim
36 words
The system of claim 4 in which said means for providing a plurality of range-azimuth paths includes means for responding to filter number signals varying by one adjacent dopper filter number to detect an unfolded target.
Claim 7
Dependent Claim
23 words
The system of claim 5 in which said means for providing a plurality of range-azimuth paths provides 17 paths for detecting a target.
Claim 8
Dependent Claim
40 words
The system of claim 1 in which multiplexing means is included in said correlator means for applying the filter number signals from said first, second and third storage registers to said correlator means in a predetermined pulse repetition frequency order.
Claim 9
Independent Claim
196 words
A system for detecting unambiguous target range over a plurality of range bins in a radar system transmitting a plurality of bursts of pulses, each burst during a burst interval, with each sequential burst being at a different pulse repetition frequency and being repetitive on a modulo 3 basis, the radar system receiving return pulses comprising: doppler processing means having a plurality of filters for providing doppler filter number signals for each filter responding to the reception of said return pulses; first, second and third recirculating storage means coupled in series, with said first storage means coupled to said doppler processing means for receiving and storing said filter number signals; first control means coupled to said recirculating storage means for transferring the stored filter number signals between the first, second and third storage means after each burst interval; second control means coupled to said recirculating storage means for recirculating the stored filter number signals on a range bin basis in each storage means; and correlating means responsive to the stored signals recirculated in said storage means for determining as a function of doppler filter number, range bin number and storage means number, an unambiguous target range.
Claim 10
Independent Claim
196 words
A system for detecting unambiguous target range over a plurality of range bins in a radar system transmitting a plurality of bursts of pulses, each burst during a burst interval, with each sequential burst being at a different pulse repetition frequency and being repetitive on a modulo 3 basis, the radar system receiving return pulses comprising: doppler processing means having a plurality of filters for providing doppler filter number signals for each filter responding to the reception of said return pulses; first, second and third recirculating storage means coupled in series, with said first storage means coupled to said doppler processing means for receiving and storing said filter number signals; first control means coupled to said recirculating storage means for transferring the stored filter number signals between the first, second and third storage means after each burst interval; second control means coupled to said recirculating storage means for recirculating the stored filter number signals on a range bin basis in each storage means; and correlating means responsive to the stored signals recirculated in said storage means for determining as a function of doppler filter number, range bin number and storage means number, an unambiguous target range.
Claim 11
Dependent Claim
54 words
The system of claim 8 in which multiplexing means is included in said correlating means to provide said doppler signals in a predetermined pulse repetition frequency order from said first, second and third storage means to said correlating means as the pulse repetition frequency order changes in said first, second and third storage means.
Claim 12
Dependent Claim
40 words
The system of claim 9 in which said correlating means includes means for detecting the presence of at least one of a predetermined number of range versus dwell paths provided over filter numbers varying positively and negatively by one number.
Claim 13
Dependent Claim
14 words
The system of claim 10 in which said correlating means includes 17 predetermined paths.
Claim 14
Dependent Claim
31 words
The system of claim 11 including threshold means at the input to said first storage means so that doppler filter number signals are only provided when a predetermined threshold is exceeded.
Claim 15
Dependent Claim
27 words
The system of claim 12 including range counting means responsive to the detecting of a target by said correlating means to provide unambiguous range of said target.
Claim 16
Dependent Claim
253 words
An unambiguous radar range determining system responsive to transmitted bursts of pulses with each burst representing a dwell period and being transmitted at different pulse repetition frequencies on a modulo 3 basis, said system defining a plurality of range bins and including a doppler filter bank having a plurality of frequency adjacent doppler filters responding to signals derived from radar return signals to provide filter numbers comprising: first, second and third recirculating shift registers coupled in series, with the first register coupled to said doppler filter bank for receiving data including filter numbers during each dwell period; control means coupled to said recirculating shift registers for controlling said registers during each dwell period to load said first register, to recirculate the data in said first, second and third registers and to transfer the data in sequence between said first, second and third registers with the data received in said third register during the previous dwell period being removed therefrom, said registers storing data in three dwell orders; multiplexing means coupled to said first, second and third registers to provide the data in a predetermined one of said three dwell orders; correlator means coupled to said multiplexing means to receive said data in said predetermined order and having a plurality of range versus dwell detecting paths responding to filter numbers for detecting the presence of an unfolded target signal in each range bin; and priority means responsive to detection of unfolded target signals by said correlator means to provide an unambiguous target range signal.
Claim 17
Dependent Claim
253 words
An unambiguous radar range determining system responsive to transmitted bursts of pulses with each burst representing a dwell period and being transmitted at different pulse repetition frequencies on a modulo 3 basis, said system defining a plurality of range bins and including a doppler filter bank having a plurality of frequency adjacent doppler filters responding to signals derived from radar return signals to provide filter numbers comprising: first, second and third recirculating shift registers coupled in series, with the first register coupled to said doppler filter bank for receiving data including filter numbers during each dwell period; control means coupled to said recirculating shift registers for controlling said registers during each dwell period to load said first register, to recirculate the data in said first, second and third registers and to transfer the data in sequence between said first, second and third registers with the data received in said third register during the previous dwell period being removed therefrom, said registers storing data in three dwell orders; multiplexing means coupled to said first, second and third registers to provide the data in a predetermined one of said three dwell orders; correlator means coupled to said multiplexing means to receive said data in said predetermined order and having a plurality of range versus dwell detecting paths responding to filter numbers for detecting the presence of an unfolded target signal in each range bin; and priority means responsive to detection of unfolded target signals by said correlator means to provide an unambiguous target range signal.
Claim 18
Dependent Claim
33 words
The combination of claim 14 in which said correlator means includes 17 range versus dwell detecting paths over a range of doppler filter number variations of plus or minus one adjacent filter number.
References Cited (Backward Citations)
US3727215A
Cited
US3532867A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-08-07 | 1982-02-06 | 1982-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-07 | 1986-02-06 | 1986-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-07 | 1990-02-06 | 1990-08-08 | $7700.00 | Window Closed / Lapsed |