US3913099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic, digitally controlled radar target matched filter
Assignee: United States Department of the Navy
•
Filing: 1970-06-24
•
Granted: 1975-10-14
•
Expires: 1990-06-24
Abstract
Abstract An automatic, digitally controlled apparatus for improving radar target recognition and identification capabilities of high-range resolution radars. A transmitted high-range resolution pulse train produces a complex echo signal from a target illuminated thereby. The echo signal from the target illuminated consists of a series of discrete RF response pulses reflected from the scatter centers on the target. Each scatter center produces a reflected RF pulse response that is separated in time with respect to the other RF pulses an amount proportional to the position of its corresponding scatter center on the target with respect to the other scatter centers. Each response is processed in a different one of a plurality of delay channels having a variable delay element that is responsive to digital control signals. By selectively energizing each delay element in the delay channels, the RF pulses or responses received first are delayed until the last RF pulse or response in each echo signal is received. The processed response from each of the scatter centers can then be combined such that the combined peak response from the target will comprise an algebraic superposition of the individual responses from the scatter centers. Stored digital control signals based upon a priori target range profile signature data and corresponding to matched conditions for known targets are applied to the delay channels so that when the response from the target under surveillance matches to a matched condition for a known target, the target under surveillance is thereby identified.
Inventors
- 👤 Donald R Wehner
- 👤 Michael J Prickett
- 👤 Raymond B Gylling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:06
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/28; G01S7/2806
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
301 words
A digital system for automatically identifying a remote radar target having a plurality of scatter centers comprising: microwave energy means for illuminating said target with a highrange resolution RF pulse train; receiver means for receiving reflected microwave energy from said target; said reflected microwave energy comprising a range profile signature of said target and consisting of a plurality of discrete RF pulses, each of said RF pulses corresponding to the energy reflected from one of said plurality of scatter centers of said target, and each of said RF pulses having a time-separation with respect to each other proportional to the physical separation of said scatter centers of said target; matched filter means connected to said receiver means, said filter means comprising a plurality of variable, microwave delay channels, and further including power divider means for coupling each of said discrete RF pulses to a different one of said delay channels, each of said delay channels comprising a bank of delay lines, each of said delay lines having a fixed delay and further including digital switch means associated with each of said delay lines; a source of digital control signals connected to said filter means, means for applying digital control signals from said source to energize selectively predetermined ones of said switch means to thereby connect in series the corresponding delay lines whereby in each channel a total delay is obtained which is substantially equal to the sum of the serially connected delay lines in that channel; each of said discrete RF pulses being delayed in its corresponding delay channel an amount substantially equal to said time-separation between said RF pulses; and means for coherently combining said time-delayed RF pulses to obtain an output waveform having an amplitude substantially equal to the sum of the amplitudes of the several discrete RF pulses.
Claim 2
Dependent Claim
301 words
A digital system for automatically identifying a remote radar target having a plurality of scatter centers comprising: microwave energy means for illuminating said target with a highrange resolution RF pulse train; receiver means for receiving reflected microwave energy from said target; said reflected microwave energy comprising a range profile signature of said target and consisting of a plurality of discrete RF pulses, each of said RF pulses corresponding to the energy reflected from one of said plurality of scatter centers of said target, and each of said RF pulses having a time-separation with respect to each other proportional to the physical separation of said scatter centers of said target; matched filter means connected to said receiver means, said filter means comprising a plurality of variable, microwave delay channels, and further including power divider means for coupling each of said discrete RF pulses to a different one of said delay channels, each of said delay channels comprising a bank of delay lines, each of said delay lines having a fixed delay and further including digital switch means associated with each of said delay lines; a source of digital control signals connected to said filter means, means for applying digital control signals from said source to energize selectively predetermined ones of said switch means to thereby connect in series the corresponding delay lines whereby in each channel a total delay is obtained which is substantially equal to the sum of the serially connected delay lines in that channel; each of said discrete RF pulses being delayed in its corresponding delay channel an amount substantially equal to said time-separation between said RF pulses; and means for coherently combining said time-delayed RF pulses to obtain an output waveform having an amplitude substantially equal to the sum of the amplitudes of the several discrete RF pulses.
Claim 3
Dependent Claim
197 words
Digitally-controlled, matched filter apparatus for use with high-range resolution radar systems wherein a remote target to be identified is illuminated with a pulse train to produce a target range profile signature return which is unique for the particular target under surveillance and comprising: power divider means for dividing said signature into the discrete, constituent responses thereof and produced by the individual scatter centers of said target; a plurality of like delay channel means, each of said channel means being connected to the output of said power divider means to receive a different one of said responses and comprising: input terminal means for receiving said response; output terminal means; a bank of microwave delay means connected between said input and output terminals; digitally-responsive switch means connected to each of said delay means; a source of digital control signals for energizing any of said switch means or any combination thereof whereby the corresponding delay lines are connected in a series manner with respect to each other between said input and output terminal means; and, power combiner means connected to the output of each of said delay channel means to combine the outputs thereof into a single composite output signal.
Claim 4
Dependent Claim
197 words
Digitally-controlled, matched filter apparatus for use with high-range resolution radar systems wherein a remote target to be identified is illuminated with a pulse train to produce a target range profile signature return which is unique for the particular target under surveillance and comprising: power divider means for dividing said signature into the discrete, constituent responses thereof and produced by the individual scatter centers of said target; a plurality of like delay channel means, each of said channel means being connected to the output of said power divider means to receive a different one of said responses and comprising: input terminal means for receiving said response; output terminal means; a bank of microwave delay means connected between said input and output terminals; digitally-responsive switch means connected to each of said delay means; a source of digital control signals for energizing any of said switch means or any combination thereof whereby the corresponding delay lines are connected in a series manner with respect to each other between said input and output terminal means; and, power combiner means connected to the output of each of said delay channel means to combine the outputs thereof into a single composite output signal.
Claim 5
Dependent Claim
36 words
The apparatus of claim 2 wherein each of said delay means comprises a coaxial delay line and wherein each of said switch means comprises two pairs of PIN-diode phase-shifters connected across the input and output thereof.
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) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |