GB1408016A - Pulse-operated radar receivers - Google Patents
Pulse-operated radar receiversInfo
- Publication number
- GB1408016A GB1408016A GB5927772A GB5927772A GB1408016A GB 1408016 A GB1408016 A GB 1408016A GB 5927772 A GB5927772 A GB 5927772A GB 5927772 A GB5927772 A GB 5927772A GB 1408016 A GB1408016 A GB 1408016A
- Authority
- GB
- United Kingdom
- Prior art keywords
- filter
- target
- cut
- frequency
- observation time
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H17/00—Networks using digital techniques
- H03H17/02—Frequency selective networks
- H03H17/0294—Variable filters; Programmable filters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/50—Systems of measurement based on relative movement of target
- G01S13/52—Discriminating between fixed and moving objects or between objects moving at different speeds
- G01S13/522—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves
- G01S13/524—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi
- G01S13/526—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi performing filtering on the whole spectrum without loss of range information, e.g. using delay line cancellers or comb filters
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H17/00—Networks using digital techniques
- H03H17/02—Frequency selective networks
- H03H17/04—Recursive filters
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Mathematical Physics (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
1408016 Pulse radar SIEMENS AG 21 Dec 1972 [23 Dec 1971] 59277/72 Heading H4D A pulse radar receiver includes in its video stage a moving-echo filter followed by a variable cut-off digital low-pass filter whose cut-off frequency is progressively reduced during the target observation time. The Specification states that in a radar of this type the optimum frequency of the low-pass filter is inversely proportional to the observation time. Therefore as the observation time increases without detection of the target the filter cut-off is reduced, thus nominally increasing the signal-to-noise ratio, If the filter is followed by a threshold detector the threshold can be simultaneously lowered to provide a constant false alarm rate, but ensuring a more rapid positive targetno target decision if sequential detection is used. In a radar using a phased array antenna 1 coherently detected pulses are amplitude coded and subjected to fixed target cancellation in moving echo filter 11. The unipolar pulses due to moving targets are fed to a digital low-pass filter TP comprising two identical cascaded stages F1, F2. The filter parameters are determined by the gains of A1, A2, D1, D2 which are controlled by a store or computer 25. This also controls the switching of the antenna array 1 and sets the maximum observation times in any particular direction; these may be preprogrammed or derived from a tracking sequence. The filter output is passed to a threshold 23 which has upper and lower limits OS, US. These limits are lowered and raised respectively during the target observation time. Crossing of either limit by the filter output terminates the observation and produces a target/no target signal for indicator 24. On the decision being made store or computer 25 progresses to the next antenna direction. The variation of the cut-off frequency may be begun or ended by a portion of constant frequency or the variation may be progressive throughout.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19712164156 DE2164156C3 (en) | 1971-12-23 | 1971-12-23 | Pulse radar receiver with a digital low-pass filter with a variable cut-off frequency connected downstream |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1408016A true GB1408016A (en) | 1975-10-01 |
Family
ID=5829013
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB5927772A Expired GB1408016A (en) | 1971-12-23 | 1972-12-21 | Pulse-operated radar receivers |
Country Status (5)
Country | Link |
---|---|
DE (1) | DE2164156C3 (en) |
FR (1) | FR2164653B1 (en) |
GB (1) | GB1408016A (en) |
IT (1) | IT971591B (en) |
NL (1) | NL7217575A (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2297517A1 (en) * | 1975-01-10 | 1976-08-06 | Thomson Csf | BAND COMPRESSION DEVICE AND ACTIVE DETECTION SYSTEM INCLUDING SUCH A DEVICE |
FR2340554A1 (en) * | 1976-02-03 | 1977-09-02 | Thomson Csf | PULSE-COHERENT RADAR SIGNAL PROCESSING DEVICE AND RADAR SYSTEM INCLUDING SUCH A DEVICE |
FR2472759A1 (en) * | 1979-12-28 | 1981-07-03 | Thomson Csf | DEVICE FOR REMOVING FIXED ECHO IN ELECTROMAGNETIC DETECTION EQUIPMENT AND EQUIPMENT COMPRISING SUCH A DEVICE |
DE3803446C1 (en) * | 1988-02-05 | 1989-08-10 | Ant Nachrichtentechnik Gmbh, 7150 Backnang, De | |
FR2719955B1 (en) * | 1994-05-10 | 1996-08-23 | Sagem | Method for filtering a threshold crossing signal. |
-
1971
- 1971-12-23 DE DE19712164156 patent/DE2164156C3/en not_active Expired
-
1972
- 1972-12-06 IT IT3254872A patent/IT971591B/en active
- 1972-12-18 FR FR7245012A patent/FR2164653B1/fr not_active Expired
- 1972-12-21 GB GB5927772A patent/GB1408016A/en not_active Expired
- 1972-12-22 NL NL7217575A patent/NL7217575A/xx unknown
Also Published As
Publication number | Publication date |
---|---|
DE2164156A1 (en) | 1973-07-05 |
IT971591B (en) | 1974-05-10 |
NL7217575A (en) | 1973-06-26 |
DE2164156B2 (en) | 1974-12-19 |
DE2164156C3 (en) | 1975-08-14 |
FR2164653A1 (en) | 1973-08-03 |
FR2164653B1 (en) | 1976-10-29 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |