Patent US5212489A successfully refreshed from Google Patents.
US5212489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Echo ranging system for detecting velocity of targets using composite doppler invariant transmissions
Assignee: Hydroacoustics Inc
•
Filing: 1992-08-20
•
Granted: 1993-05-18
•
Expires: 2012-08-20
Abstract
Abstract Target velocity and range are measured with high resolution in an echo ranging system (sonar or radar) using composite Doppler invariant signals consisting of at least two segments, such as "rooftop" or "vee" HFM signals, such composite signals having ambiguity functions that intersect along the zero-velocity time axis with ridge lines slanted in different directions. A single correlator is used for each segment wherein returns from the target are correlated with replicas of each segment of the composite signal to separately transform the Doppler frequency shifts of the target return into outputs whose time relationship provides a frame of reference for high resolution measurement of the velocity of the target. The time relationship measurement is implemented by a set of tapped delay lines and coherent summers which output a coherent correlation-like detection peak in a bin which corresponds to the target's velocity. Thus, one correlator for each transmission segment together with a tapped delay line and summer network may be used for velocity detection, with high precision range detection, based upon the timing of the detection peak with respect to the transmitted signal, also being implemented at the same time, thereby avoiding the classical need for an expensive bank of correlators (one for each velocity bin) and yielding significant economies for the simultaneous high resolution measurement of range and velocity for a target by means of echo ranging.
Inventors
- 👤 David E. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:55
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/58; G01S13/583; G01S13/06; G01S13/08; G01S13/10; G01S13/26; G01S15/00; G01S15/02; G01S15/50; G01S15/58; G01S15/586
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
157 words
Apparatus for measuring simultaneously the velocity and range of a target which comprises means for generating a composite signal having a plurality of segments which define an ambiguity function in time and velocity having at least two ridge lines which have different time-velocity slopes and which intersect along the zero-velocity time axis of said ambiguity function, means for transmitting at a transmit time said composite signal in the direction of a target, means for receiving a composite return signal from said target following incidence of said composite signals thereon, means for correlating the composite return signal with replicas of each of said segments to transform the frequency shift of said target return due to the velocity thereof into outputs occurring in time-delayed relationships corresponding to the velocity and range of the target, and means for coherently summing said outputs in time-delayed relationship to produce a plurality of coherent sums from which target velocity and range are determinable.
Claim 2
Dependent Claim
157 words
Apparatus for measuring simultaneously the velocity and range of a target which comprises means for generating a composite signal having a plurality of segments which define an ambiguity function in time and velocity having at least two ridge lines which have different time-velocity slopes and which intersect along the zero-velocity time axis of said ambiguity function, means for transmitting at a transmit time said composite signal in the direction of a target, means for receiving a composite return signal from said target following incidence of said composite signals thereon, means for correlating the composite return signal with replicas of each of said segments to transform the frequency shift of said target return due to the velocity thereof into outputs occurring in time-delayed relationships corresponding to the velocity and range of the target, and means for coherently summing said outputs in time-delayed relationship to produce a plurality of coherent sums from which target velocity and range are determinable.
Claim 3
Independent Claim
153 words
A method for detecting simultaneously the velocity and range of a target which comprises the steps of generating a composite signal having a plurality of segments which define an ambiguity function in time and velocity having at least two ridge lines which have different time-velocity slopes and which intersect along the zero-velocity time axis of said ambiguity function, transmitting said composite signal at a certain time in the direction of a target, receiving a composite return signal from said target following incidence of said composite signal thereon, correlating the composite return signal with replicas of each of said segments to transform the frequency shift of said target return due to the velocity thereof into outputs occurring in time-delayed relationships corresponding to the velocity and range of the target, and said outputs coherently said outputs summing them in time-delayed relationship to produce a plurality of sums from which target velocity and range are determinable.
Claim 4
Independent Claim
153 words
A method for detecting simultaneously the velocity and range of a target which comprises the steps of generating a composite signal having a plurality of segments which define an ambiguity function in time and velocity having at least two ridge lines which have different time-velocity slopes and which intersect along the zero-velocity time axis of said ambiguity function, transmitting said composite signal at a certain time in the direction of a target, receiving a composite return signal from said target following incidence of said composite signal thereon, correlating the composite return signal with replicas of each of said segments to transform the frequency shift of said target return due to the velocity thereof into outputs occurring in time-delayed relationships corresponding to the velocity and range of the target, and said outputs coherently said outputs summing them in time-delayed relationship to produce a plurality of sums from which target velocity and range are determinable.
Claim 5
Independent Claim
125 words
A method for detecting the velocity of a target which comprises the steps of generating a composite signal having a plurality of segments which define an ambiguity function in time and velocity having at least two intersecting ridge lines which have different time-velocity slopes, receiving a return signal from said target following incidence of said composite signal thereon, and correlating the return signal separately with replicas of each of said segments to transform the frequency shift of said return signal from said target due to the velocity thereof into coherently related outputs occurring in time-delayed relationship corresponding to the velocity of the target, and coherently summing said outputs in amplitude and phase in time-delayed relationship to provide a plurality of sums to determine said velocity.
Claim 6
Independent Claim
125 words
A method for detecting the velocity of a target which comprises the steps of generating a composite signal having a plurality of segments which define an ambiguity function in time and velocity having at least two intersecting ridge lines which have different time-velocity slopes, receiving a return signal from said target following incidence of said composite signal thereon, and correlating the return signal separately with replicas of each of said segments to transform the frequency shift of said return signal from said target due to the velocity thereof into coherently related outputs occurring in time-delayed relationship corresponding to the velocity of the target, and coherently summing said outputs in amplitude and phase in time-delayed relationship to provide a plurality of sums to determine said velocity.
Claim 7
Dependent Claim
20 words
The method according to claim 3 wherein each of said segments of said composite signal has a Doppler invariant waveform.
Claim 8
Dependent Claim
31 words
The method according to claim 4 wherein said composite signal has a duration containing the time interval of each of said segments thereof during which each said segment varies in frequency.
Claim 9
Dependent Claim
36 words
The method according to claim 5 wherein the instantaneous frequency, f i , of each said segment at each instant during its time interval is f.sub.i =F/(1-kt) where F and k are constants during said segments.
Claim 10
Dependent Claim
22 words
The method according to claim 6 wherein said signal segments occur successively and said signal is a rooftop or vee HFM signal.
Claim 11
Dependent Claim
16 words
The method according to claim 5 wherein said signal segments are hyperbolic frequency modulated (HFM) signals.
Claim 12
Dependent Claim
15 words
The method according to claim 5 wherein said signal segments occur simultaneously within said duration.
Claim 13
Dependent Claim
15 words
The method according to claim 5 wherein said signal segments occur successively during said duration.
Claim 14
Dependent Claim
126 words
The method according to claim 4 wherein said composite signal includes a plurality of pairs of said signal segments each of which said pairs defines within said ambiguity function a different pair of ridge lines sloping in opposite directions with different slopes, and said correlating step provides a plurality of pairs of said outputs upon correlation of said return signal with replicas of each of said signal segments, said coherently combining step comprises coherently combining said outputs corresponding to different ones of said pairs of segments with different relative delays, and selecting from said combined outputs the one of maximum amplitude to identify the velocity of said target, in accordance with the relative delay producing said maximum amplitude, while suppressing ambiguous return signals from said target.
Claim 15
Dependent Claim
77 words
The method according to claim 3 wherein said outputs from said correlating step comprise a first output and a second output, and wherein said summing step is carried out by successively delaying each of said outputs and coherently summing each said successively delayed first output with each of said successively delayed second output to produce said plurality of coherent sums, and detecting the velocity of said target in accordance with the maximum amplitude one of said sums.
Claim 16
Dependent Claim
60 words
The method according to claim 12 wherein said step of successively delaying said outputs is carried out by propogating each of said outputs along different delay lines having successive taps, and said summing step is carried out with the aid of a plurality of summers, each of said summers being connected to different taps of different ones of said lines.
Claim 17
Dependent Claim
119 words
The method according to claim 13 wherein said generating step further comprises modulating a carrier having a higher frequency than the highest frequency of said composite signal with said composite signal, and said receiving step includes the step of recovering said return signal as a signal coherent with said modulated carrier signal at said carrier frequency or a frequency shifted from said carrier frequency and providing said output as samples at a rate at least twice the frequency of said return signal as recovered during said recovering step, said propagating step is carried out by propagating said samples along said delay line and said summing step is carried out by coherently summing said samples at each of said taps.
Claim 18
Dependent Claim
82 words
The method according to claim 3 wherein said outputs comprise at least a first output and second output, and said summing step is carried out by successively delaying said first and second outputs to provide a first succession of successively delayed second outputs, and coherently summing said first and second successions of outputs in inverse time order to produce said plurality of coherent sums thereof, the one of said sums which is of maximum amplitude corresponding to the velocity of said target.
Claim 19
Dependent Claim
62 words
The method according to claim 15 wherein said successively delaying step is carried out by propagating said first and second outputs along first and second delay lines having successive taps, and said summing step is carried out with the aid of a plurality of summers connected to taps which are progressively closer to opposite ends of said first and second delay lines.
Claim 20
Dependent Claim
111 words
The method according to claim 16 wherein said generating step further comprises modulating a carrier having a higher frequency than the highest frequency of said composite signal with said composite signal, and said receiving step includes the step of recovering said return signal as a signal coherent with said modulated carrier signal at said carrier frequency or providing said output as samples at a rate at least twice the frequency of said return signal as recovered during said recovering step, said propagating step is carried out by propagating said samples along said delay line, and said summing step is carried out by coherently summing said samples at each of said taps.
Claim 21
Dependent Claim
20 words
The method according to claim 3 wherein said signal segments of said composite signals are transmitted at the same time.
Claim 22
Dependent Claim
14 words
The method according to claim 3 wherein said different slopes are in opposite directions.
Claim 23
Dependent Claim
23 words
The method according to claim 19 wherein said ridge lines slant in opposite directions with respect to the time axis of said function.
Claim 24
Dependent Claim
13 words
The method according to claim 3 wherein said replicas are zero velocity replicas.
Claim 25
Dependent Claim
105 words
In an echo-ranging system, which illuminates an object with a composite signal transmission having first and second components which sweep in time and opposite directions with respect to frequency and which is returned as a return signal from said object, a system for detecting the velocity of said object which comprises means for correlating said return signal with replicas of said components to provide a pair of outputs corresponding to said first and second components, and means for delaying and coherently summing said outputs to produce a plurality of coherent sums, and means for detecting the velocity of said object from said plurality of sums.
Claim 26
Dependent Claim
105 words
In an echo-ranging system, which illuminates an object with a composite signal transmission having first and second components which sweep in time and opposite directions with respect to frequency and which is returned as a return signal from said object, a system for detecting the velocity of said object which comprises means for correlating said return signal with replicas of said components to provide a pair of outputs corresponding to said first and second components, and means for delaying and coherently summing said outputs to produce a plurality of coherent sums, and means for detecting the velocity of said object from said plurality of sums.
Claim 27
Dependent Claim
39 words
The velocity detecting system according to claim 22, wherein said transmission is a composite Doppler invariant FM transmission, and said detecting means includes means responsive to the one of said plurality of sums which is maximum, identifying said velocity.
Claim 28
Dependent Claim
27 words
The system according to claim 23 further comprising means responsive to said one of said sums for detecting the range of said object from a reference location.
Claim 29
Dependent Claim
57 words
The system according to claim 22 wherein said summing combining means includes means for relatively delaying said pair of outputs to provide a plurality of further outputs having different relative delays, and means for summing said further delayed outputs to provide a plurality of summer outputs, and means responsive to said summer outputs for detecting said velocity.
Claim 30
Dependent Claim
118 words
Apparatus for detecting the velocity of a target which comprises means for generating a composite signal having a plurality of segments which define an ambiguity function in time and velocity having at least two intersecting ridge lines which have different time-velocity slopes, means for receiving a return signal from said target upon incidence of said composite signal thereon, means for correlating the return signal with replicas of each of said segments to transform the frequency shift of said return signal from said target due to the velocity thereof into coherently related outputs occurring in time-delayed relationship corresponding to the velocity of said target, and summing said outputs to provide a plurality of coherent sums to detect said velocity.
Claim 31
Dependent Claim
118 words
Apparatus for detecting the velocity of a target which comprises means for generating a composite signal having a plurality of segments which define an ambiguity function in time and velocity having at least two intersecting ridge lines which have different time-velocity slopes, means for receiving a return signal from said target upon incidence of said composite signal thereon, means for correlating the return signal with replicas of each of said segments to transform the frequency shift of said return signal from said target due to the velocity thereof into coherently related outputs occurring in time-delayed relationship corresponding to the velocity of said target, and summing said outputs to provide a plurality of coherent sums to detect said velocity.
Claim 32
Dependent Claim
18 words
The apparatus according to claim 26 wherein each segment of said composite signal has a Doppler invariant waveform.
Claim 33
Dependent Claim
26 words
The apparatus according to claim 27 wherein said composite signal has a duration containing each said segment thereof during which each said segment varies in frequency.
Claim 34
Dependent Claim
36 words
The apparatus according to claim 28 wherein the instantaneous frequency, f i , of each said segment at each instant during its time interval is f.sub.i =F/(1-kt) where F and k are constants during said segments.
Claim 35
Dependent Claim
16 words
The apparatus according to claim 28 wherein said signal segments are hyperbolic frequency modulated (HFM) signals.
Claim 36
Dependent Claim
21 words
The apparatus according to claim 28 wherein said generating means includes means for producing said signal segments simultaneously within said duration.
Claim 37
Dependent Claim
21 words
The apparatus according to claim 28 wherein said generating means includes means for producing said signal segments successively during said duration.
Claim 38
Dependent Claim
23 words
The apparatus according to claim 28 wherein said generating means includes means for producing said signal as a rooftop or vee HFM signal.
Claim 39
Dependent Claim
69 words
The apparatus according to claim 28 wherein said composite signal includes a plurality of pairs of signal segments, each pair of said signal segments defining within said ambiguity function a different pair of ridge lines sloping in opposite directions with different slopes, and said correlating means including means for providing a plurality of pairs of said outputs upon correlation of said return signal with replicas of said signal segments.
Claim 40
Independent Claim
71 words
The apparatus according to claim, 26 wherein said outputs comprise a first output and a second output, and wherein said summing means comprises means for successively delaying said outputs and coherently summing each said successively delayed first output with each said successively delayed second output to produce said plurality of coherent sums, and means for detecting the velocity of said target in accordance with the maximum amplitude one of said sums.
Claim 41
Dependent Claim
69 words
The apparatus according to claim 35 wherein said means for successively delaying said outputs includes first and second delay lines having successive taps, means for propagating said first output and said second output, respectively, along said first delay line and said second delay line, and said summing means includes a plurality of summers each of said summers being connected to a different taps of different ones of said lines.
Claim 42
Dependent Claim
118 words
The apparatus according to claim 36 wherein said generating means further comprises means for modulating a carrier having a higher frequency than the highest frequency of said composite signal with said composite signal, and said receiving means includes means for recovering said return signal as a signal coherent with said modulated carrier signal at said carrier frequency or a frequency shifted from said carrier frequency and for providing said output as samples at a rate at least twice the frequency of said return signal as recovered by said receiving means, said propagating means being operative to propagate said samples along said delay line, and said summing means being operative to sum said samples at each of said taps.
Claim 43
Independent Claim
93 words
The apparatus according to claim, 26 wherein said outputs comprise at least a first output and a second output, and said summing means comprises means for successively delaying said first and second outputs to provide a first succession of successively delayed first outputs and a second succession of successively delayed second outputs, and means for coherently summing said first and second successions of outputs in inverse time order to produce said plurality of coherent sums thereof, the one of said sums which is of maximum amplitude corresponding to the velocity of said target.
Claim 44
Dependent Claim
62 words
The apparatus according to claim 38 wherein said successively delaying means comprises first and second delay lines having successive taps, and means for propagating said first and second outputs along said first and second delay lines, and said summing means comprises a plurality of summers connected to taps which are progressively closer to opposite ends of said first and second delay lines.
Claim 45
Dependent Claim
117 words
The apparatus according to claim 39 wherein said generating means further comprises means for modulating a carrier having a higher frequency than the highest frequency of said composite signal with said composite signal, and said receiving means includes means for recovering said return signal as a signal coherent with said modulated carrier signal at said carrier frequency or a frequency shifted from said carrier frequency and providing said output as samples at a rate at least twice the frequency of said return signal as recovered by said receiving means, said propagating means being operative to propagate said samples along said delay line, and said summing means being operative to sum said samples at each of said taps.
Claim 46
Dependent Claim
33 words
The apparatus according to claim 26 further comprising means for measuring the range of said target in response to the one of said plurality of coherent sums from which said velocity is obtained.
Claim 47
Dependent Claim
13 words
The apparatus according to claim 26 wherein said replicas are zero velocity replicas.
Claim 48
Dependent Claim
27 words
The apparatus according to claim 1 further comprising means for determining said target velocity and range from the one sum of said plurality exhibiting the highest magnitude.
Claim 49
Dependent Claim
28 words
The method according to claim 2 further comprising the step of determining said target velocity and range from the one sum of said plurality exhibiting the highest magnitude.
Claim 50
Dependent Claim
31 words
The system according to claim 22 wherein said means responsive to said plurality of coherent sums includes means for providing at least one combined output which is maximum identifying said velocity.
Claim 51
Dependent Claim
24 words
The apparatus according to claim 26 in which said plurality of coherent sums includes at least one sum which is maximum identifying said velocity.
References Cited (Backward Citations)
US3225349A
Cited
US3579180A
Cited
US3905033A
Cited
US3622963A
Cited
US3808594A
Cited
US3866223A
Cited
US4106019A
Cited
USRE31509E
Cited
US4697186A
Cited
US4053889A
Cited
US4398274A
Cited
US4493064A
Cited
US4509051A
Cited
US4566011A
Cited
US4831602A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-17 | 1996-11-16 | 1997-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-17 | 2000-11-16 | 2001-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-17 | 2004-11-16 | 2005-05-18 | $7700.00 | Window Closed / Lapsed |