GB1192290A - An Echo Filtering Arrangement for Radar Systems - Google Patents
An Echo Filtering Arrangement for Radar SystemsInfo
- Publication number
- GB1192290A GB1192290A GB60520/68A GB6052068A GB1192290A GB 1192290 A GB1192290 A GB 1192290A GB 60520/68 A GB60520/68 A GB 60520/68A GB 6052068 A GB6052068 A GB 6052068A GB 1192290 A GB1192290 A GB 1192290A
- Authority
- GB
- United Kingdom
- Prior art keywords
- return
- returns
- memory
- channel
- doppler
- 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
- 238000001914 filtration Methods 0.000 title 1
- 230000006870 function Effects 0.000 abstract 4
- 238000002592 echocardiography Methods 0.000 abstract 3
- 230000003321 amplification Effects 0.000 abstract 1
- 230000001427 coherent effect Effects 0.000 abstract 1
- 238000003199 nucleic acid amplification method Methods 0.000 abstract 1
- 230000010355 oscillation Effects 0.000 abstract 1
- 230000004044 response Effects 0.000 abstract 1
Classifications
-
- 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
-
- 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
- G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
- G01S13/64—Velocity measuring systems using range gates
-
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/28—Details of pulse systems
- G01S7/285—Receivers
- G01S7/292—Extracting wanted echo-signals
- G01S7/2923—Extracting wanted echo-signals based on data belonging to a number of consecutive radar periods
- G01S7/2926—Extracting wanted echo-signals based on data belonging to a number of consecutive radar periods by integration
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
1,192,290. Radar. THOMSON C.S.F. 19 Dec., 1968 [20 Dec., 1967; 10 May, 1968], No. 60520/68. Heading H4D. Specification describes a pulsed Doppler radar, Fig. 1, wherein, to simulate the function of an "ideal" Doppler filter, a plurality of consecutive returns, each containing echoes from the same target, are each weighted (at X) by an amount dependant on the order of the particular return within the plurality and said weighted returns are summed and wherein to overcome the necessity of storing each weighted return prior to the summation, each weighted return is consecutively fed to a summing junction # having at its other input the output of a memory device M, the output of said junction updating the memory content and providing the signal at said other input for the subsequent return. If the response of the ideal filter is H (t) and the echo signal is E(t), then the output of the filter is given by This function is approximated by the inventors as the sum over n returns of The term H(#/2 + iT), calculable by a given formula, gives the weighting factor for the particular return. In the radar of Fig. 2, step scan control B causes the antenna A n to stay in one position for such a time that n returns from the target occur. A clock Fr gates the output of coherent transmitter E at the repetition frequency; under the control of sync. circuit Sy. The received echoes are processed in receiver R and the if signals are fed to weighting amplifier. The weighting by function H(t) is performed in two stages-an analogue stage is amplifier A and a digital stage is shift circuit T 3 . The amplification of stage A is varied from one return to the next according to the stored signal in memory M, read out by the clock Fr. Negative values of this weighting are allowed for by inverter I. The partially weighted returns are fed to m Doppler channels each detecting echoes having Doppler shifts with predetermined ranges. Each channel is comprised by two sub-channels, one a "sine" channel and the other a "cosine" channel. The channels feed into and receive the content of (in the describd manner of summing junction #), memory M. Each return is time quantized at E 3 in N range gates. Memory M thus comprises 2m N storage positions. Each channel comprises a "sine" phase detector D 3 and a "cosine" phase detector respectively fed with the outputs of a local oscillation in phase quadrature. The frequency of the oscillator O, Fig. 2a (not shown), is Fm + fdi, where F m is the if frequency and fdi is a frequency different for each channel and determining the Doppler frequency range of the channel. The output of the detector D 3 is time quantized and converted to digital form in means E 3 and the digital return subjected to the second stage of weighting in shifting circuit, wherein the digital contents are shifted (i.e. multiplied) by amounts stored in memory M 2 , read out by clock Fr. The totally shifted returns are applied as explained above to summing function # 3 . The total contents of memory M are read out to utalization devised at the end of the n returns. An embodiment utalizing transmitted pulse pairs, to overcome Doppler ambiguities is also described, Fig. 8 (not shown).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR132993 | 1967-12-20 | ||
FR151297A FR94959E (en) | 1967-12-20 | 1968-05-10 | Device for filtering echoes in electromagnetic detection devices with discontinuous scanning. |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1192290A true GB1192290A (en) | 1970-05-20 |
Family
ID=26181664
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB60520/68A Expired GB1192290A (en) | 1967-12-20 | 1968-12-19 | An Echo Filtering Arrangement for Radar Systems |
Country Status (4)
Country | Link |
---|---|
DE (1) | DE1815974A1 (en) |
FR (1) | FR94959E (en) |
GB (1) | GB1192290A (en) |
SE (1) | SE359166B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3116390A1 (en) * | 1980-04-25 | 1982-06-03 | Raytheon Co., 02173 Lexington, Mass. | PROCESSING DEVICE FOR RADAR SYSTEMS FOR DISPLAYING MOVABLE DESTINATIONS |
US4488154A (en) * | 1980-04-25 | 1984-12-11 | Raytheon Company | Radar processor |
CN118091553A (en) * | 2024-04-25 | 2024-05-28 | 清华大学 | Generalized waveform description-based radar waveform generation method and apparatus |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3444473A1 (en) * | 1984-12-06 | 1986-06-19 | Messerschmitt-Bölkow-Blohm GmbH, 8012 Ottobrunn | Device for detecting sea targets |
-
1968
- 1968-05-10 FR FR151297A patent/FR94959E/en not_active Expired
- 1968-12-19 SE SE17487/68A patent/SE359166B/xx unknown
- 1968-12-19 GB GB60520/68A patent/GB1192290A/en not_active Expired
- 1968-12-20 DE DE19681815974 patent/DE1815974A1/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3116390A1 (en) * | 1980-04-25 | 1982-06-03 | Raytheon Co., 02173 Lexington, Mass. | PROCESSING DEVICE FOR RADAR SYSTEMS FOR DISPLAYING MOVABLE DESTINATIONS |
US4488154A (en) * | 1980-04-25 | 1984-12-11 | Raytheon Company | Radar processor |
CN118091553A (en) * | 2024-04-25 | 2024-05-28 | 清华大学 | Generalized waveform description-based radar waveform generation method and apparatus |
Also Published As
Publication number | Publication date |
---|---|
DE1815974A1 (en) | 1969-08-21 |
FR94959E (en) | 1970-02-27 |
SE359166B (en) | 1973-08-20 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed [section 19, patents act 1949] | ||
PCNP | Patent ceased through non-payment of renewal fee |