US3911432A
Expired / Lapsed
US
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Technique for eliminating mutual interference between adjacent asynchronous radar systems
Assignee: United States Department of the Navy
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Filing: 1974-04-17
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Granted: 1975-10-07
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Expires: 1994-04-17
Abstract
Abstract A method for eliminating mutual interference between two adjacent radar systems without the use of transmission pulse synchronization wherein A. IF THE RADAR SYSTEMS ARE IN A SEARCH MODE AND THEIR OPERATING FREQUENCIES ARE CLOSE ENOUGH TO CAUSE INTERFERENCE, THEN THE RECEIVERS ARE BLANKED; B. IF THE SYSTEMS ARE USING RANGE-GATE MODES (TRACKING) AND THERE IS AN OVERLAP OF ONE SYSTEM''S TRANSMISSION WITH ANOTHER SYSTEM''S RANGE-GATE, THEN TIME DELAYS ARE INSERTED IN THE TRANSMISSION AND RANGE-GATE TABLES OF THE SYSTEMS TO ELIMINATE THIS OVERLAP, I. THE TIME DELAYS MAY BE INSERTED SO AS TO INTERWINE THE TRANSMISSIONS AND RANGE-GATES OF THE SYSTEMS, OR II. THE TIME DELAYS MAY BE INSERTED SO AS TO SHIFT THE INTERFERING TRANSMISSIONS COMPLETELY PAST THE LAST RANGE-GATE OF THE INTERFERED-WITH SYSTEM.
Inventors
- 👤 James K Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:29
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/023; G01S13/00; G01S13/87; G01S7/0235
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
206 words
A method to eliminate mutual interference between two radar systems each system containing a digital processor comprising the steps of: a. monitoring by each system of the present and future transmission and reception activity of the other system; b. slaving the digital processor of each system to the same master clock; c. synchronizing periodically the operation of the digital processors to a reference signal; d. when a system desires to transmit a radar beam, comparing its transmission frequency with the transmission frequency of the other system; e. determining whether the difference between these two frequencies is less than some predetermined number; f. if these systems are in a search-beam mode and if this difference is less than this predetermined number, blanking the receivers of both systems; g. if these systems are in a tracking-mode and if this difference is less than the predetermined number, determining whether the transmit and range-gate time of this system will overlap the transmit and range-gate time of the other system; h. if the overlap will occur, determining a time delay so that there will be no overlap of a transmission with a range-gate; i. inserting this time delay into the timing table of the beam to be transmitted from this system.
Claim 2
Independent Claim
206 words
A method to eliminate mutual interference between two radar systems each system containing a digital processor comprising the steps of: a. monitoring by each system of the present and future transmission and reception activity of the other system; b. slaving the digital processor of each system to the same master clock; c. synchronizing periodically the operation of the digital processors to a reference signal; d. when a system desires to transmit a radar beam, comparing its transmission frequency with the transmission frequency of the other system; e. determining whether the difference between these two frequencies is less than some predetermined number; f. if these systems are in a search-beam mode and if this difference is less than this predetermined number, blanking the receivers of both systems; g. if these systems are in a tracking-mode and if this difference is less than the predetermined number, determining whether the transmit and range-gate time of this system will overlap the transmit and range-gate time of the other system; h. if the overlap will occur, determining a time delay so that there will be no overlap of a transmission with a range-gate; i. inserting this time delay into the timing table of the beam to be transmitted from this system.
Claim 3
Independent Claim
227 words
A method to eliminate mutual interference between two radar systems, each of said systems containing a digital processor, comprising the steps of: a. monitoring by each system of the present and future transmission and reception activity of the other system; b. slaving the digital processor of each system to the same master clock; c. synchronizing periodically the operation of the digital processors to a reference signal; d. when a system desires to transmit a radar beam, comparing its transmission frequency with the transmission frequency of the other system; e. determining whether the difference between these two frequencies is less than some predetermined number; f. if these systems are in a search-beam mode and if this difference is less than this predetermined number, blanking the receivers of both systems; g. if these systems are in a tracking-mode and if this difference is less than the predetermined number, determining whether the transmit and range-gate time of this system will overlap the transmit and range-gate time of the other system; h. if the overlap will occur, determining a time delay such that the beginning of the one system''s interfering transmission is shifted completely in time past the end of the last range-gate of the interfered-with reception period of the other system; and i. inserting this time delay into the timing table of the beam to be transmitted from this system.
Claim 4
Independent Claim
227 words
A method to eliminate mutual interference between two radar systems, each of said systems containing a digital processor, comprising the steps of: a. monitoring by each system of the present and future transmission and reception activity of the other system; b. slaving the digital processor of each system to the same master clock; c. synchronizing periodically the operation of the digital processors to a reference signal; d. when a system desires to transmit a radar beam, comparing its transmission frequency with the transmission frequency of the other system; e. determining whether the difference between these two frequencies is less than some predetermined number; f. if these systems are in a search-beam mode and if this difference is less than this predetermined number, blanking the receivers of both systems; g. if these systems are in a tracking-mode and if this difference is less than the predetermined number, determining whether the transmit and range-gate time of this system will overlap the transmit and range-gate time of the other system; h. if the overlap will occur, determining a time delay such that the beginning of the one system''s interfering transmission is shifted completely in time past the end of the last range-gate of the interfered-with reception period of the other system; and i. inserting this time delay into the timing table of the beam to be transmitted from this system.
Claim 5
Independent Claim
225 words
A method to eliminate mutual interference between two radar systems, each of said systems containing a digital processor, comprising the steps of: a. monitoring by each system of the present and future transmission and reception activity of the other system; b. slaving the digital processor of each system to the same master clock; c. synchronizing periodically the operation of the digital processors to a reference signal; d. when a system desires to transmit a radar beam, comparing its transmission frequency with the transmission frequency of the other system; e. determining whether the difference between these two frequencies is less than some predetermined number; f. if these systems are in a search-beam mode and if this difference is less than this predetermined number, blanking the receivers of both systems; g. if these system are in a tracking-mode and if this difference is less than the predetermined number, determining whether the transmit and range-gate time of this system will overlap the transmit and range-gate time of the other system; h. if the overlap will occur, determining a time delay such that the staRt of the one system''s range-gates is shifted completely in time past the end of the last pulse of the interfering transmission of the other system; and i. inserting this time delay into the timing table of the beam to be transmitted from this system.
Claim 6
Independent Claim
225 words
A method to eliminate mutual interference between two radar systems, each of said systems containing a digital processor, comprising the steps of: a. monitoring by each system of the present and future transmission and reception activity of the other system; b. slaving the digital processor of each system to the same master clock; c. synchronizing periodically the operation of the digital processors to a reference signal; d. when a system desires to transmit a radar beam, comparing its transmission frequency with the transmission frequency of the other system; e. determining whether the difference between these two frequencies is less than some predetermined number; f. if these systems are in a search-beam mode and if this difference is less than this predetermined number, blanking the receivers of both systems; g. if these system are in a tracking-mode and if this difference is less than the predetermined number, determining whether the transmit and range-gate time of this system will overlap the transmit and range-gate time of the other system; h. if the overlap will occur, determining a time delay such that the staRt of the one system''s range-gates is shifted completely in time past the end of the last pulse of the interfering transmission of the other system; and i. inserting this time delay into the timing table of the beam to be transmitted from this system.
Claim 7
Independent Claim
252 words
A method to eliminate mutual interference between two radar systems, each of said systems containing a digital processor and wherein each system transmission comprises a set of pulses and each system reception period comprises a set of range-gates comprising the steps of: a. monitoring by each system of the present and future transmission and reception activity of the other system; b. slaving the digital processor of each system to the same master clock; c. synchronizing periodically the operation of the digital processors to a reference signal; d. when a system desires to transmit a radar beam comparing its transmission frequency with the transmission frequency of the other system; e. determining whether the difference between these two frequencies is less than some predetermined number; f. if these systems are in a search-beam mode and if this difference is less than this predetermined number, blanking the receivers of both systems; g. if these systems are in a tracking-mode and if this difference is less than the predetermined number, determining whether the transmit and range-gate time of this system will overlap the transmit and range-gate time of the other system; h. if the overlap will occur, determining a time delay such that the set of pulses comprising the interfering transmission for the one system is intertwined in time with no overlap with the set of range gates comprising the interfered-with reception period of the other system; and i. inserting this time delay into the timing table of the beam to be transmitted from this system.
Claim 8
Independent Claim
252 words
A method to eliminate mutual interference between two radar systems, each of said systems containing a digital processor and wherein each system transmission comprises a set of pulses and each system reception period comprises a set of range-gates comprising the steps of: a. monitoring by each system of the present and future transmission and reception activity of the other system; b. slaving the digital processor of each system to the same master clock; c. synchronizing periodically the operation of the digital processors to a reference signal; d. when a system desires to transmit a radar beam comparing its transmission frequency with the transmission frequency of the other system; e. determining whether the difference between these two frequencies is less than some predetermined number; f. if these systems are in a search-beam mode and if this difference is less than this predetermined number, blanking the receivers of both systems; g. if these systems are in a tracking-mode and if this difference is less than the predetermined number, determining whether the transmit and range-gate time of this system will overlap the transmit and range-gate time of the other system; h. if the overlap will occur, determining a time delay such that the set of pulses comprising the interfering transmission for the one system is intertwined in time with no overlap with the set of range gates comprising the interfered-with reception period of the other system; and i. inserting this time delay into the timing table of the beam to be transmitted from this system.
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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |