CN109597060B - Radar speed measurement method and device - Google Patents
Radar speed measurement method and device Download PDFInfo
- Publication number
- CN109597060B CN109597060B CN201811495780.6A CN201811495780A CN109597060B CN 109597060 B CN109597060 B CN 109597060B CN 201811495780 A CN201811495780 A CN 201811495780A CN 109597060 B CN109597060 B CN 109597060B
- Authority
- CN
- China
- Prior art keywords
- pulse
- echo signal
- autocorrelation
- pulse echo
- signal
- 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.)
- Active
Links
- 238000000691 measurement method Methods 0.000 title abstract description 12
- 238000000034 method Methods 0.000 claims abstract description 34
- 230000001427 coherent effect Effects 0.000 claims description 118
- 238000004364 calculation method Methods 0.000 claims description 36
- 238000005070 sampling Methods 0.000 claims description 21
- 102100021699 Eukaryotic translation initiation factor 3 subunit B Human genes 0.000 claims description 6
- 101000896557 Homo sapiens Eukaryotic translation initiation factor 3 subunit B Proteins 0.000 claims description 6
- 238000005259 measurement Methods 0.000 abstract description 7
- 238000005516 engineering process Methods 0.000 description 6
- 238000001514 detection method Methods 0.000 description 5
- 238000002592 echocardiography Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000000819 phase cycle Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 230000033001 locomotion Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
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
- G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
- G01S13/588—Velocity or trajectory determination systems; Sense-of-movement determination systems deriving the velocity value from the range measurement
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
The embodiment of the application discloses a radar speed measurement method, which comprises the following steps: acquiring a first pulse echo signal and a second pulse echo signal which are adjacent on a distance library b, wherein the first pulse echo signal corresponds to a first pulse in a staggered PRT sequence, the second pulse echo signal corresponds to a second pulse in the staggered PRT sequence, and the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the staggered PRT sequence; further, the velocity at the range bin b is calculated from the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse in the staggered PRT sequence, and the initial phase of the second pulse in the staggered PRT sequence. The method effectively expands the speed measurement range of the staggered PRT sequence.
Description
Technical Field
The present application relates to the field of communications technologies, and in particular, to a method and an apparatus for measuring a speed by a radar.
Background
Doppler radar, also known as pulse doppler radar, is a radar that uses the doppler effect to detect the position and relative velocity of a moving object. Doppler radar is widely applied in the field of meteorological detection nowadays, and the distribution conditions of various air turbulence motions in the atmospheric layers with different heights can be obtained by distinguishing the Doppler velocity of meteorological echoes, so that relevant meteorological information can be obtained.
For a Doppler radar with uniform Pulse Repetition Time (PRT), the maximum unambiguous range R is obtained once the radar wavelength is determinedmaxAnd maximum unambiguous velocity VmaxThe product of (A) is a constant c λ/8(c represents the speed of light and λ represents the radar wavelength), and if R is to be increasedmaxOr VmaxThen the other variable must be scaled down accordingly, which is a doppler dilemma. In order to solve the problem, the staggered PRT technology is developed, which alternately transmits two pulses with PRT T1 and PRT T2 in a radial direction, and expands the speed measurement range of the radar by using the principle that the maximum unambiguous speed of different pulses with PRT is different.
However, the current staggered PRT technique has a large limitation on the detection range of the velocity, and specifically, if the previous pulse generates an echo at a target object beyond the maximum detection range that can be detected by the previous pulse, the echo will reach the receiver within the echo receiving time corresponding to the next pulse, and the receiver cannot judge the pulse specifically corresponding to the echo, so that the velocity beyond the maximum detection range cannot be effectively measured, that is, the detection range of the velocity is limited.
Disclosure of Invention
In order to solve the technical problem, the application provides a radar speed measurement method which can effectively expand the speed measurement range of the staggered PRT.
The embodiment of the application discloses the following technical scheme:
in a first aspect, an embodiment of the present application provides a radar speed measurement method, where the method includes:
acquiring a first pulse echo signal and a second pulse echo signal which are adjacent to each other on a distance library b; the first pulse echo signal corresponds to a first pulse in a staggered pulse repetition time, PRT, sequence, and the second pulse echo signal corresponds to a second pulse in the staggered PRT sequence; the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the staggered PRT sequence;
calculating a velocity at the range bin b from the first pulse echo signal, the second pulse echo signal, the initial phase of a first pulse in the staggered PRT sequence, and the initial phase of a second pulse in the staggered PRT sequence.
In a second aspect, an embodiment of the present application provides a radar speed measuring device, where the device includes:
the acquisition module is used for acquiring a first pulse echo signal and a second pulse echo signal which are adjacent to each other on the distance library b; the first pulse echo signal corresponds to a first pulse in a staggered pulse repetition time, PRT, sequence, and the second pulse echo signal corresponds to a second pulse in the staggered PRT sequence; the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the staggered PRT sequence;
and the calculating module is used for calculating the speed at the distance library b according to the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse in the staggered PRT sequence and the initial phase of the second pulse in the staggered PRT sequence.
According to the technical scheme, the application provides a radar speed measurement method, which comprises the following steps: acquiring a first pulse echo signal and a second pulse echo signal which are adjacent on a distance library b, wherein the first pulse echo signal corresponds to a first pulse in a staggered PRT sequence, the second pulse echo signal corresponds to a second pulse in the staggered PRT sequence, and the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the staggered PRT sequence; further, the velocity at the range bin b is calculated from the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse in the staggered PRT sequence, and the initial phase of the second pulse in the staggered PRT sequence.
According to the radar speed measurement method, a random coding technology is utilized, when each pulse in the staggered PRT sequence is transmitted, an initial phase is randomly assigned to each pulse, the initial phase of each pulse is recorded, and further, after a pulse echo signal is acquired from a distance library b with a corresponding distance larger than the maximum unambiguous distance corresponding to the staggered PRT sequence, the acquired pulse echo signal can be correspondingly coherent to the corresponding pulse according to the initial phase of the pulse recorded in advance, and then the speed of the distance library b is calculated according to the coherent pulse coherent signal, so that the speed measurement range of the staggered PRT sequence is effectively expanded.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.
Fig. 1 is a schematic flowchart of a radar speed measurement method according to an embodiment of the present disclosure;
FIG. 2 is a flowchart illustrating a method for calculating a velocity at a distance bin b according to an embodiment of the present disclosure;
fig. 3 is a schematic diagram of an echo provided in an embodiment of the present application;
FIG. 4 is a schematic flow chart of another method for calculating a velocity at a distance bin b according to an embodiment of the present disclosure;
FIG. 5 is a schematic diagram of another echo provided by an embodiment of the present application;
fig. 6 is a schematic structural diagram of a radar speed measuring device according to an embodiment of the present application.
Detailed Description
In order to make the technical solutions of the present application better understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Aiming at the problem that the speed measuring range of the existing staggered PRT sequence is limited, the embodiment of the application provides a radar speed measuring method, which utilizes a random phase coding technology to correspondingly endow each pulse with an initial phase when each pulse in the staggered PRT sequence is transmitted, and record the initial phase corresponding to each pulse, further, when a pulse echo signal is acquired at a distance library b with a corresponding distance greater than the maximum unambiguous distance corresponding to the staggered PRT sequence, the speed at the distance library b is calculated according to the pre-recorded initial phase and the acquired pulse echo signal, so that the speed detecting range is not limited to the maximum unambiguous distance corresponding to the staggered PRT sequence any more, and the speed measuring range of the staggered PRT sequence is effectively expanded.
The radar speed measurement method provided by the present application is specifically introduced below by way of an embodiment.
Referring to fig. 1, fig. 1 is a schematic flow chart of a radar speed measurement method provided in an embodiment of the present application. As shown in fig. 1, the method includes:
step 101: and acquiring a first pulse echo signal and a second pulse echo signal which are adjacent on the distance library b.
The distance library is a minimum distance unit divided according to distance along the radial direction in radar echo signal processing, and different distance libraries correspond to different distances. The distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the staggered PRT sequence, and the maximum unambiguous distance corresponding to the staggered PRT sequence is equal to the maximum unambiguous distance corresponding to a Pulse with higher Pulse Repetition Frequency (PRF) in the staggered PRT sequence, namely equal to the maximum unambiguous distance corresponding to a Pulse with smaller PRT in the staggered PRT sequence; for example, if the staggered PRT sequence includes alternately transmitting a pulse with a PRF of 1200Hz and a pulse with a PRF of 800Hz, where the maximum unambiguous distance corresponding to the pulse with a PRF of 1200Hz is 125km, and the maximum unambiguous distance corresponding to the pulse with a PRF of 800Hz is 187.5km, the maximum unambiguous distance corresponding to the pulse with a maximum unambiguous distance of 1200Hz corresponding to the staggered PRT sequence is 125 km.
It should be understood that any distance library with a corresponding distance greater than the maximum unambiguous distance corresponding to the staggered PRT sequence may be used as the distance library b, and the distance corresponding to the distance library b is not otherwise limited.
The first pulse echo corresponds to a first pulse in the staggered PRT sequence, and is an echo generated after the first pulse reaches the target object; similarly, the second pulse echo corresponds to a second pulse in the staggered PRT sequence, which is an echo generated after the second pulse reaches the target object; it should be understood that the distance corresponding to the above-mentioned target is larger than the maximum unambiguous distance corresponding to the staggered PRT sequence.
It should be noted that, the staggered PRT sequence includes a plurality of first pulses and second pulses which are alternately transmitted, and accordingly, when receiving the pulse echo, a first pulse echo corresponding to the first pulse and a second pulse echo corresponding to the second pulse are alternately received. It should be understood that the above-mentioned step of acquiring the first pulse echo signal and the second pulse echo signal adjacent to the range bin b is not limited to acquiring two pulse echo signals, and in practical applications, a plurality of first pulse echo signals and second pulse echo signals which are alternately returned are generally received.
Step 102: and calculating the speed at the distance library b according to the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse in the staggered PRT sequence and the initial phase of the second pulse in the staggered PRT sequence.
After the first pulse echo signal and the second pulse echo signal are acquired, correspondingly, the speed at the distance library b is calculated according to the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse in the staggered PRT sequence and the initial phase of the second pulse in the staggered PRT sequence.
It should be noted that, when the staggered PRT sequence is transmitted, that is, when the first pulse and the second pulse are alternately transmitted, the pulse transmitting apparatus randomly assigns an initial phase to each of the first pulse and the second pulse by using a random phase encoding technique, records the initial phase corresponding to each of the first pulse and the second pulse, and further, when the velocity at the distance library b is calculated, the calculation is performed according to the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse, and the initial phase of the second pulse.
The above method for calculating the speed at the distance bin b will be described below for the case that the distance intervals at which the distances corresponding to the distance bin b are located are different.
When the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the first pulse and less than the maximum unambiguous distance corresponding to the second pulse (the PRT corresponding to the first pulse is less than the PRT corresponding to the second pulse, that is, the PRF corresponding to the first pulse is greater than the PRF corresponding to the second pulse); the flow of the method for calculating the speed at the distance bin b is shown in fig. 2, which includes:
step 201: and correspondingly, according to the initial phase corresponding to each first pulse in the staggered PRT sequence, each first pulse echo signal is coherent to the corresponding first pulse, so that a first coherent signal corresponding to each first pulse echo signal is obtained.
It should be understood that, since the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the first pulse, the receiving time of each first pulse echo signal exceeds the echo receiving time period of its corresponding first pulse, that is, the receiving time of each first pulse echo signal is actually within the echo receiving time period of the second pulse, and therefore, in order to calculate the speed at the distance library b from the first pulse echo signals, it is necessary to use the initial phase of its corresponding first pulse to coherently correlate the first pulse echo signals with its corresponding first pulse, that is, to obtain first coherent signals.
Step 202: and correspondingly calculating second autocorrelation signals corresponding to the second pulse echo signals according to the initial phases corresponding to the second pulses in the staggered PRT sequence and the second pulse echo signals.
It should be understood that, since the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the first pulse and less than the maximum unambiguous distance corresponding to the second pulse, the receiving time of each second pulse echo signal is still within the echo receiving time period of the second pulse corresponding to itself, and therefore, the second autocorrelation signal corresponding to each second pulse echo signal can be calculated directly according to the initial phase of each second pulse echo signal and the second pulse corresponding to each second pulse echo signal.
It should be noted that, in practical applications, step 201 may be executed first and then step 202 is executed, step 202 may be executed first and then step 201 is executed, and step 201 and step 202 may also be executed simultaneously, where the execution order of step 201 and step 202 is not limited at all.
Step 203: calculating a first autocorrelation phase from each first coherent signal and each second autocorrelation signal; a first radial velocity is calculated based on the first autocorrelation phase.
Step 204: calculating a second autocorrelation phase from each second autocorrelation signal and each first coherent signal; a second radial velocity is calculated based on the second autocorrelation phase.
After the first coherent signal and the second autocorrelation signal are obtained through calculation, a first autocorrelation phase and a second autocorrelation phase can be calculated according to each first coherent signal and each second autocorrelation signal obtained through calculation, and then a first radial velocity and a second radial velocity are calculated according to the first autocorrelation phase and the second autocorrelation phase respectively.
It should be noted that, in practical applications, step 203 may be executed first and then step 204 is executed, step 204 may be executed first and then step 203 is executed, and step 203 and step 204 may also be executed simultaneously, where the execution sequence of step 203 and step 204 is not limited at all.
Step 205: from the first radial velocity and the second radial velocity, the velocity at the distance bin b is calculated.
After the first radial speed and the second radial speed are obtained through calculation, the speed at the distance base b can be calculated by utilizing a remainder theorem according to the first radial speed and the second radial speed; it should be understood that, in practical applications, other algorithms may be used to calculate the velocity at the distance library b according to the first radial velocity and the second radial velocity, and the method for calculating the calculated velocity is not limited herein.
It should be noted that, in order to prevent the calculation flow shown in fig. 2 from being executed when both the acquired first pulse echo signal and the acquired second pulse echo signal are noise signals, unnecessary calculation operations are performed, and calculation resources are wasted; before calculating the speed at the distance library b, the average power corresponding to the distance library b may be calculated according to each second pulse echo signal, and when the average power corresponding to the distance library b is greater than the preset signal-to-noise ratio threshold, the calculation process shown in fig. 2 is executed.
It should be understood that, since the receiving time of the second pulse echo signal is within the echo receiving time period of the second pulse corresponding to the second pulse, theoretically, the second pulse echo signal is not doped with pulse echo signals corresponding to other pulses, and accordingly, the average power corresponding to the range bin b calculated according to the second pulse echo signal can be used to determine whether the second pulse echo signal belongs to a noise signal; when the average power corresponding to the distance library b calculated according to the second pulse echo signal is greater than the preset signal-to-noise ratio threshold value, it can be determined that the second pulse echo signal is not a noise signal, and correspondingly, the first pulse echo signal from the same target object is not a noise signal, so that the speed at the distance library b can be calculated according to the first pulse echo signal and the second pulse echo signal; on the contrary, when the average power corresponding to the distance library b calculated according to the second pulse echo signal is less than or equal to the preset signal-to-noise ratio threshold value, it may be determined that the second pulse echo signal is a noise signal, and correspondingly, the first pulse echo signal from the same target object is also a noise signal, so that it is not necessary to calculate the speed at the distance library b according to the first pulse echo signal and the second pulse echo signal.
It should be understood that the preset snr threshold may be set according to actual situations, and is usually set to be 3dB, and of course, the preset snr threshold may also be set to be other values, and no specific limitation is made on the preset snr threshold herein.
In order to further understand the speed calculation method shown in fig. 2, the calculation method is exemplified below by taking the case where the radar alternately transmits the C band with a PRF of 1200Hz and a wavelength of 800Hz and a wavelength of 5 cm.
When the radar alternately transmits waves with PRF of 1200Hz and 800HzWhen the pulse length is long, assuming that a pulse with a PRF of 1200Hz is a first pulse, a pulse with a PRF of 800Hz is a second pulse, the maximum unambiguous distance corresponding to the first pulse is 125km, and the maximum unambiguous distance corresponding to the second pulse is 187.5 km; the echo reception period PRT1 of the first pulse is divided into two time units T11And T12The distance corresponding to each time unit is 62.5km, and the echo receiving time PRT2 of the second pulse is divided into three time units T21、T22And T23The distance corresponding to each time unit is also 62.5 km.
As shown in fig. 3, when the distance corresponding to the distance library b is greater than the maximum unambiguous distance of the first pulse and less than the maximum unambiguous distance of the second pulse, the receiving time of the echo signal of the first pulse is at time unit T21The time of reception of the second pulse echo signal is at time unit T23The inner, i.e. the shaded area in fig. 3, is the time unit in which the reception times of the first pulse-echo signal and the second pulse-echo signal are located.
Firstly, the sampling number of the pulse echo at the distance library b is assumed to be 2N, namely, 2N first pulse echo signals and 2N second pulse echo signals are collected in total, and the initial phase sequence of the staggered PRT sequence is
(k-1, … …,2N) comprising N first pulses and N second pulses.
Calculating initial phase complex numbers corresponding to each initial phase by burst sampling
Before calculating the velocity at the distance bin b, the average power corresponding to the distance bin b may be calculated according to the second pulse echo signal, and the specific calculation formula is as follows:
wherein, p (b) is the average power corresponding to the distance library b; xt23(b)2kA second autocorrelation signal corresponding to the kth second pulse echo; x is the number oft23(b)2kIQ complex number of the kth second pulse echo signal; a is2kIs the initial phase complex number of the second pulse corresponding to the k second pulse echo signal,
is the conjugate of the initial phase complex number of the second pulse; n represents the number of samples of the second pulse echo signal.
Judging whether p (b) is larger than a preset signal-to-noise ratio threshold value th _ snr or not; if the second pulse echo signal is smaller than the first pulse echo signal, the second pulse echo signal is a noise signal, and the speed at the distance library b does not need to be calculated continuously; if so, the following calculation process is continued.
Will be at time unit T21The received pulse echo signal is coherent to a first pulse corresponding to the received pulse echo signal, and a first coherent signal is obtained. Note that, since the time unit T21Belonging to the echo reception time for the second pulse, and therefore, in time unit T21The received pulse-echo signal may include both a primary echo corresponding to the second pulse and a secondary echo corresponding to a first pulse adjacent to and preceding the second pulse (first pulse-echo signal); the pulse echo signal is coherent to the corresponding first pulse, that is, the pulse signal is coherent to the first pulse corresponding to the first pulse echo signal included therein, and the specific calculation formula is as follows:
wherein, X't21(b)2kA first coherent signal corresponding to the kth first pulse echo signal; x is the number oft21(b)2kAt time unit T21Received pulseIQ complex number of echo signal; a is2k-1Is the initial phase complex number of the first pulse corresponding to the k-th first pulse echo signal,
is the conjugate of the initial phase complex number; and N is the sampling times of the first pulse echo signal.
Calculating time unit T23The formula of the second autocorrelation signal of the received second pulse echo signal is shown in the above formula (2).
Calculating a time unit T2 based on the first coherent signal and the second autocorrelation signal1The first-order autocorrelation phase, i.e., the first autocorrelation phase, is calculated as follows:
wherein,
is a first autocorrelation phase; x't21(b)2kA first coherent signal corresponding to the kth first pulse signal,
is the conjugate of the first coherent signal; xt23(b)2kA second autocorrelation signal corresponding to a second pulse signal adjacent to and collected after the kth first pulse signal; n represents the number of samples of the first pulse echo signal.
Calculating a time unit T2 according to the first autocorrelation phase1The corresponding radial velocity, i.e. the first radial velocity, is calculated as follows:
wherein, v't21(b) A first radial velocity;
is a first autocorrelation phase; PRT1 is the pulse repetition time for the first pulse.
Calculating a time unit T2 based on the second autocorrelation signal and the first coherent signal3The first-order autocorrelation phase, i.e., the second autocorrelation phase, is calculated as follows:
wherein,
is the second autocorrelation phase; xt23(b)2kA second autocorrelation signal corresponding to the kth second pulse echo signal,
is the conjugate of the second autocorrelation signal; x't21(b)2k+2A first coherent signal corresponding to a second pulse echo signal adjacent to and received after the kth second pulse; n represents the number of samples of the second pulse echo signal.
Calculating the time unit T2 according to the second autocorrelation phase3The corresponding radial velocity, i.e. the second radial velocity, is calculated as follows:
wherein v ist23(b) A second radial velocity;
is the second autocorrelation phase; PRT2 is the pulse repetition time for the second pulse.
Finally, according to the remainder theorem, obtaining the first radial speed v 'according to calculation't21(b) And a second radial velocity vt23(b) The speed at the distance bin b (in this case, the distance corresponding to the distance bin b is 125km-187.5 km).
When the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the second pulse (where the PRT corresponding to the first pulse is less than the PRT corresponding to the second pulse, that is, the PRF corresponding to the first pulse is greater than the PRF corresponding to the second pulse); the flow of the method for calculating the velocity at the distance bin b is shown in fig. 4, which includes:
step 401: and correspondingly, according to the initial phase corresponding to each first pulse in the staggered PRT sequence, each first pulse echo is coherent to the corresponding first pulse, and a first coherent signal corresponding to each first pulse echo signal is obtained.
Step 402: and correspondingly coherent the second pulse echoes to the second pulses corresponding to the second pulse echoes according to the initial phases corresponding to the second pulses in the staggered PRT sequence to obtain second coherent signals corresponding to the second pulse echoes.
It should be understood that, since the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the second pulse, and accordingly, the distance corresponding to the distance library b is also greater than the maximum unambiguous distance corresponding to the first pulse, the receiving time of each first pulse echo signal has exceeded the echo receiving time period of its corresponding first pulse, and the receiving time of each second pulse echo signal has exceeded the echo receiving time period of its corresponding second pulse.
In order to calculate the velocity at the range bin b according to the first pulse echo and the second pulse echo, the first pulse echo signal needs to be coherent to the corresponding first pulse by using the initial phase of the first pulse corresponding to the first pulse echo signal, so as to obtain a first coherent signal; and coherent the second pulse echo signal to the corresponding second pulse by using the initial phase of the second pulse corresponding to the second pulse echo signal to obtain a second coherent signal.
It should be noted that, in practical applications, step 401 may be executed first and then step 402 may be executed, step 402 may be executed first and then step 401 may be executed, and step 401 and step 402 may also be executed simultaneously, where the execution order of step 401 and step 402 is not limited at all.
Step 403: calculating a first autocorrelation phase from each first coherent signal and each second coherent signal; a first radial velocity is calculated based on the first autocorrelation phase.
Step 404: calculating a second autocorrelation phase from each second coherent signal and each first coherent signal; a second radial velocity is calculated based on the second autocorrelation phase.
After the first coherent signal and the second coherent signal are obtained through calculation, a first autocorrelation phase and a second autocorrelation phase can be calculated according to each first coherent signal and each second coherent signal obtained through calculation, and then a first radial velocity and a second radial velocity are calculated according to the first autocorrelation phase and the second autocorrelation phase respectively.
It should be noted that, in practical applications, step 403 may be executed first and then step 404 is executed, step 404 may be executed first and then step 403 is executed, and step 403 and step 404 may also be executed simultaneously, where the execution order of step 403 and step 404 is not limited at all.
Step 405: from the first radial velocity and the second radial velocity, the velocity at the distance bin b is calculated.
After the first radial speed and the second radial speed are obtained through calculation, the speed at the distance base b can be calculated by utilizing a remainder theorem according to the first radial speed and the second radial speed; it should be understood that, in practical applications, other algorithms may be used to calculate the velocity at the distance library b according to the first radial velocity and the second radial velocity, and the method for calculating the calculated velocity is not limited herein.
It should be noted that, in order to prevent the calculation flow shown in fig. 3 from being executed when both the acquired first pulse echo signal and the acquired second pulse echo signal are noise signals, unnecessary calculation operations are performed, and calculation resources are wasted; before calculating the velocity at the distance bin b, a first autocorrelation amplitude may be calculated from the first pulse-echo signal, and a second autocorrelation amplitude may be calculated from the first coherent signal; calculating a third autocorrelation amplitude according to the second pulse echo signal, and calculating a fourth autocorrelation amplitude according to the second coherent signal; further, whether the second autocorrelation amplitude is larger than the first autocorrelation amplitude and whether the fourth autocorrelation amplitude is larger than the third autocorrelation amplitude are judged, if both the second autocorrelation amplitude and the fourth autocorrelation amplitude are larger than the third autocorrelation amplitude, the first pulse echo signal and the second pulse echo signal are not noise signals, and therefore the speed at the position of the distance library b can be calculated according to the first pulse echo signal and the second pulse echo signal; on the contrary, if the second autocorrelation amplitude is less than or equal to the first autocorrelation amplitude, and/or the fourth autocorrelation amplitude is less than or equal to the third autocorrelation amplitude, it indicates that the first pulse echo signal and the second pulse echo signal may be noise signals, and therefore, it is not necessary to calculate the velocity at the distance library b according to the first pulse echo signal and the second pulse echo signal.
In order to further understand the speed calculation method shown in fig. 4, the calculation method is illustrated below by taking the case where the radar alternately transmits the C band with a PRF of 1200Hz and a wavelength of 800Hz and a wavelength of 5cm as an example.
When the radar alternately transmits the wavelengths with the PRF of 1200Hz and 800Hz, assuming that the pulse with the PRF of 1200Hz is a first pulse, the pulse with the PRF of 800Hz is a second pulse, the maximum unambiguous distance corresponding to the first pulse is 125km, and the maximum unambiguous distance corresponding to the second pulse is 187.5 km; the echo reception period PRT1 of the first pulse is divided into two time units T11And T12The distance corresponding to each time unit is 62.5km, and the echo receiving time PRT2 of the second pulse is divided into three time units T21、T22And T23The distance corresponding to each time unit is also 62.5 km.
As shown in fig. 5, when the distance corresponding to the distance library b is greater than the maximum unambiguous distance of the first pulse and the maximum unambiguous distance of the second pulse, the receiving time of the echo signal of the first pulse is at time unit T22The time of reception of the second pulse echo signal is at time unit T11The inner, i.e. the shaded area in fig. 5, is the first pulse-echo signal and the second pulse-echo signalThe time unit in which the number is received.
Firstly, the sampling number of the pulse echo at the distance library b is assumed to be 2N, namely, 2N first pulse echo signals and 2N second pulse echo signals are collected in total, and the initial phase sequence of the staggered PRT sequence is
(k-1, … …,2N) comprising N first pulses and N second pulses.
Calculating initial phase complex numbers corresponding to each initial phase by burst sampling
Before calculating the velocity at the distance bin b, it may be determined according to the previous time unit T22The method comprises the following steps of receiving a first pulse echo signal, and calculating a first autocorrelation signal corresponding to the first pulse echo signal, wherein a specific calculation formula is as follows:
Xt22(b)2k＝xt22(b)2k·a2k，k＝1,……,N (8)
wherein, Xt22(b)2kA first autocorrelation signal corresponding to the first pulse echo signal; x is the number oft22(b)2kIQ complex number of the kth first pulse echo signal; a is2kThe initial phase complex number of the first pulse corresponding to the kth first pulse echo signal; and N is the sampling times of the first pulse echo signal.
According to time unit T22Calculates a time unit T2 of the first autocorrelation signal corresponding to each first pulse echo signal of (a)2The corresponding first autocorrelation amplitude has the following specific calculation formula:
wherein m ist22(b) Is a time unit T22A corresponding first autocorrelation amplitude; xt22(b)2kAnd Xt22(b)2k-2Is twoFirst autocorrelation signals corresponding to adjacent first pulse echo signals; and N is the sampling times of the first pulse echo signal.
Will be at time unit T22The received first pulse echo signals are coherent to the first pulse corresponding to each first pulse echo signal to obtain the first coherent signal corresponding to each first pulse echo signal, and the specific calculation formula is as follows:
wherein, X't22(b)2kAt time unit T22A first coherent signal corresponding to the sampled kth first pulse echo signal; x is the number oft22(b)2kAt time unit T22An IQ complex number of the sampled kth first pulse echo signal; a is2k-1Is the initial phase complex number of the first pulse corresponding to the k-th first pulse echo signal,
is the conjugate of the initial phase complex number; n represents the number of samples of the first pulse echo signal.
According to the time unit T22The time unit T2 is calculated from the first coherent signal corresponding to each first pulse echo signal2The corresponding second autocorrelation amplitude has the following specific calculation formula:
wherein m't22(b) Is a time unit T22Corresponding second autocorrelation amplitude, X't22(b)2kAnd X't22(b)2k-2First coherent signals corresponding to two adjacent first pulse echo signals; and N is the sampling times of the first pulse echo signal.
According to the time unit T11The received second pulse echo signal is calculated in timeUnit T11The specific calculation formula of the second autocorrelation signals corresponding to each second pulse echo signal received in the receiving unit is as follows:
Xt11(b)2k-1＝xt11(b)2k-1·a2k-1，k＝1,……,N (12)
wherein Z ist11(b)2k-1A second autocorrelation signal corresponding to the second pulse echo signal; x is the number oft11(b)2k-1IQ complex number of the kth second pulse echo signal; a is2k-1The initial phase complex number of the second pulse corresponding to the kth second pulse echo signal; and N is the sampling times of the second pulse echo signal.
According to time unit T11The second autocorrelation signal corresponding to each second pulse echo signal of (1), and the time unit T11The corresponding third autocorrelation amplitude has the following specific calculation formula:
wherein m ist11(b) Is a time unit T11A corresponding third autocorrelation amplitude; xt11(b)2k-1And Xt11(b)2k+1Second autocorrelation signals corresponding to two adjacent second pulse echo signals; and N is the sampling times of the second pulse echo signal.
Will be at time unit T11The received second pulse echo signals are coherent to the second pulse corresponding to each second pulse echo signal to obtain the second coherent signal corresponding to each second pulse echo signal, and the specific calculation formula is as follows:
wherein, X't11(b)2k-1At time unit T11A second coherent signal corresponding to the sampled kth second pulse echo signal; x is the number oft11(b)2k-1At time unit T11An IQ complex number of the sampled kth second pulse echo signal; a is2k-2Is the initial phase complex number of the second pulse corresponding to the k second pulse echo signal,
is the conjugate of the initial phase complex number; n represents the number of samples of the second pulse echo signal.
According to the time unit T11The second coherent signal corresponding to each second pulse echo signal of (4), and the time unit T1 is calculated1The corresponding fourth autocorrelation amplitude has the following specific calculation formula:
wherein m't11(b) Is a time unit T11Corresponding fourth autocorrelation amplitude, X't11(b)2k-1And X't11(b)2k+1Second coherent signals corresponding to two adjacent second pulse echo signals; and N is the sampling times of the second pulse echo signal.
Judging the second autocorrelation amplitude m't22(b) Whether or not it is greater than the first autocorrelation amplitude mt22(b) And judging the fourth autocorrelation amplitude m't11(b) Whether or not it is greater than the third autocorrelation amplitude mt11(b) If both of them are larger than the threshold value, it is determined that the second echoes of the first pulse and the second pulse exist in the distance library b, and the following calculation process is continued.
Calculating a time unit T2 from the first coherent signal and the second coherent signal calculated by the above equations (10) and (14)2The first-order autocorrelation phase, i.e., the first autocorrelation phase, is calculated as follows:
wherein,
is a first autocorrelation phase; x't22(b)2kA first coherent signal corresponding to the kth first pulse echo signal,
is the conjugate of the first coherent signal; x't11(b)2k+1A second coherent signal corresponding to the (k + 1) th second pulse echo signal; n represents the respective sampling times of the first pulse echo signal and the second pulse echo signal.
Calculating a time unit T2 according to the first autocorrelation phase2The corresponding radial velocity, i.e. the first radial velocity, is calculated as follows:
wherein, v't22(b) In the case of a first radial velocity,
for the first autocorrelation phase, PRT1 is the pulse repetition time for the first pulse.
Calculating a time unit T1 from the first coherent signal and the second coherent signal calculated by the above equations (10) and (14)1The first-order autocorrelation phase, i.e., the second autocorrelation phase, is calculated as follows:
wherein,
is the second autocorrelation phase; x't11(b)2k-1A second coherent signal corresponding to the kth second pulse echo signal,
is the conjugate of the second coherent signal; x't22(b)2kA first coherent signal corresponding to the (k + 1) th first pulse echo signal; n represents the respective sampling times of the first pulse echo signal and the second pulse echo signal.
Calculating a time unit T1 according to the second autocorrelation phase1The corresponding radial velocity, i.e. the second radial velocity, is calculated as follows:
wherein, v't11(b) In order to be the second radial velocity,
for the second autocorrelation phase, PRT2 is the pulse repetition time for the second pulse.
Finally, according to the remainder theorem, obtaining the first radial speed v 'according to calculation't22(b) And a second radial velocity v't22(b) The speed at distance bin b (in this case 187.5km-250km for distance bin b).
According to the radar speed measurement method, a random coding technology is utilized, when each pulse in the staggered PRT sequence is transmitted, an initial phase is correspondingly given to each pulse, the initial phase of each pulse is recorded, and further, after a pulse echo signal is acquired from a distance library b with the corresponding distance being larger than the maximum unambiguous distance corresponding to the staggered PRT sequence, the acquired pulse echo signal can be correspondingly coherent to the corresponding pulse according to the initial phase of the pulse recorded in advance, and then the speed of the distance library b is calculated according to the coherent pulse coherent signal, so that the speed measurement range of the staggered PRT sequence is effectively expanded.
For the above radar speed measurement method, an embodiment of the present application further provides a radar speed measurement device, see fig. 6, and fig. 6 is a schematic structural diagram of the radar speed measurement device 600 provided in the embodiment of the present application. As shown in fig. 6, the radar speed measuring device 600 includes:
an obtaining module 601, configured to obtain a first pulse echo signal and a second pulse echo signal that are adjacent to each other on a range bin b; the first pulse echo signal corresponds to a first pulse in a staggered pulse repetition time, PRT, sequence, and the second pulse echo signal corresponds to a second pulse in the staggered PRT sequence; the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the staggered PRT sequence;
a calculating module 602, configured to calculate a velocity at the distance bin b according to the first pulse echo signal, the second pulse echo signal, an initial phase of a first pulse in the staggered PRT sequence, and an initial phase of a second pulse in the staggered PRT sequence.
Optionally, the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the first pulse and smaller than the maximum unambiguous distance corresponding to the second pulse, and the PRT corresponding to the first pulse is smaller than the PRT corresponding to the second pulse;
the calculation module 602 is specifically configured to:
correspondingly, according to the initial phase corresponding to each first pulse in the staggered PRT sequence, each first pulse echo signal is coherent to the corresponding first pulse, and a first coherent signal corresponding to each first pulse echo signal is obtained;
correspondingly calculating second autocorrelation signals corresponding to the second pulse echo signals according to the initial phases corresponding to the second pulses in the staggered PRT sequence and the second pulse echo signals;
calculating a first autocorrelation phase from each of said first coherent signals and each of said second autocorrelation signals; calculating a first radial velocity from the first autocorrelation phase;
calculating a second autocorrelation phase from each of said second autocorrelation signals and each of said first coherent signals; calculating a second radial velocity according to the second autocorrelation phase;
calculating the speed at the distance bin b according to the first radial speed and the second radial speed.
Optionally, the calculating module 602 is further configured to:
calculating the average power corresponding to the distance library b according to each second pulse echo signal;
and when the average power corresponding to the distance library b is greater than a preset signal-to-noise ratio threshold value, calculating the speed at the distance library b according to the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse in the staggered PRT sequence and the initial phase of the second pulse in the staggered PRT sequence.
Optionally, the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to a second pulse, and the PRT corresponding to the first pulse is smaller than the PRT corresponding to the second pulse;
the calculation module 602 is specifically configured to:
correspondingly, according to the initial phase corresponding to each first pulse in the staggered PRT sequence, each first pulse echo signal is coherent to the corresponding first pulse, and a first coherent signal corresponding to each first pulse echo signal is obtained;
correspondingly, according to the initial phase corresponding to each second pulse in the staggered PRT sequence, each second pulse echo signal is coherent to the corresponding second pulse, and a second coherent signal corresponding to each second pulse echo signal is obtained;
calculating a first autocorrelation phase from each of the first coherent signals and each of the second coherent signals; calculating a first radial velocity from the first autocorrelation phase;
calculating a second autocorrelation phase from each of said second coherent signals and each of said first coherent signals; calculating a second radial velocity according to the second autocorrelation phase;
calculating the speed at the distance bin b according to the first radial speed and the second radial speed.
Optionally, the calculating module 602 is further configured to:
calculating a first autocorrelation amplitude from the first pulse echo signal; calculating a second autocorrelation amplitude from the first coherent signal;
calculating a third autocorrelation amplitude from the second pulse echo signal; calculating a fourth autocorrelation amplitude from the second coherent signal;
when the second autocorrelation amplitude is greater than the first autocorrelation amplitude and the fourth autocorrelation amplitude is greater than the third autocorrelation amplitude, performing the calculating of the velocity at the range bin b from the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse in the staggered PRT sequence, and the initial phase of the second pulse in the staggered PRT sequence.
According to the radar speed measuring device, the random coding technology is utilized, when each pulse in the staggered PRT sequence is transmitted, an initial phase is correspondingly given to each pulse, the initial phase of each pulse is recorded, then after a pulse echo signal is acquired from a distance library b with the corresponding distance being larger than the maximum unambiguous distance corresponding to the staggered PRT sequence, the acquired pulse echo signal can be correspondingly coherent to the corresponding pulse according to the initial phase of the pulse recorded in advance, the speed of the position of the distance library b is calculated according to the coherent pulse coherent signal, and therefore the speed measuring range of the staggered PRT sequence is effectively expanded.
It should be noted that, in the present specification, all the embodiments are described in a progressive manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the apparatus and system embodiments, since they are substantially similar to the method embodiments, they are described in a relatively simple manner, and reference may be made to some of the descriptions of the method embodiments for related points. The above-described embodiments of the apparatus and system are merely illustrative, and the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
The above description is only one specific embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (11)
1. A method for measuring a speed of a radar, the method comprising:
acquiring a first pulse echo signal and a second pulse echo signal which are adjacent to each other on a distance library b; the first pulse echo signal corresponds to a first pulse in a staggered pulse repetition time, PRT, sequence, and the second pulse echo signal corresponds to a second pulse in the staggered PRT sequence; the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the staggered PRT sequence;
calculating a velocity at the range bin b from the first pulse echo signal, the second pulse echo signal, an initial phase of a first pulse in the staggered PRT sequence, and an initial phase of a second pulse in the staggered PRT sequence;
the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the first pulse and smaller than the maximum unambiguous distance corresponding to the second pulse, and the PRT corresponding to the first pulse is smaller than the PRT corresponding to the second pulse;
said calculating a velocity at said range bin b from said first pulse echo signal, said second pulse echo signal, an initial phase of a first pulse in said staggered PRT sequence, and an initial phase of a second pulse in said staggered PRT sequence, comprising:
correspondingly, according to the initial phase corresponding to each first pulse in the staggered PRT sequence, each first pulse echo signal is coherent to the corresponding first pulse, and a first coherent signal corresponding to each first pulse echo signal is obtained;
correspondingly calculating second autocorrelation signals corresponding to the second pulse echo signals according to the initial phases corresponding to the second pulses in the staggered PRT sequence and the second pulse echo signals;
calculating a first autocorrelation phase from each of said first coherent signals and each of said second autocorrelation signals; calculating a first radial velocity from the first autocorrelation phase;
calculating a second autocorrelation phase from each of said second autocorrelation signals and each of said first coherent signals; calculating a second radial velocity according to the second autocorrelation phase;
calculating the speed at the distance bin b according to the first radial speed and the second radial speed.
2. The method of claim 1, wherein the first coherent signal is calculated according to equation (1):
wherein, X't21(b)2kA first coherent signal, x, corresponding to the kth first pulse echo signalt21(b)2kIs IQ complex number, a, of the kth second pulse echo signal2k-1The initial phase complex number of the first pulse corresponding to the kth first pulse echo signal; n represents the sampling times of the first pulse echo signal;
the second autocorrelation signal is calculated according to equation (2):
wherein, Xt23(b)2kA second autocorrelation signal, x, corresponding to the kth second pulse echo signalt23(b)2kIQ complex for k-th second pulse echo signalNumber a2kThe initial phase complex number of the second pulse corresponding to the kth second pulse echo signal; n represents the sampling times of the second pulse echo signal;
the first autocorrelation phase is calculated according to equation (3):
wherein,
is a first autocorrelation phase, X't21(b)2kFor a first coherent signal corresponding to the kth first pulse signal, Xt23(b)2k+1A second autocorrelation signal corresponding to a second pulse signal adjacent to and received after the kth first pulse signal; n represents the sampling times of the first pulse echo signal;
the first radial velocity is calculated according to equation (4):
wherein, v't21(b) In the case of a first radial velocity,
for the first autocorrelation phase, PRT1 is the pulse repetition time corresponding to the first pulse, λ is the radar wavelength;
the second autocorrelation phase is calculated according to equation (5):
wherein,
is the second autocorrelation phase, Xt23(b)2kIs a second autocorrelation signal, X 'corresponding to the kth second pulse echo signal't21(b)2k+2A first coherent signal corresponding to a second pulse echo signal adjacent to and received after the kth second pulse echo; n represents the sampling times of the second pulse echo signal;
the second radial velocity is calculated according to equation (6):
wherein v ist23(b) In order to be the second radial velocity,
for the second autocorrelation phase, PRT2 is the pulse repetition time for the second pulse.
3. The method of claim 1, further comprising:
calculating the average power corresponding to the distance library b according to each second pulse echo signal;
and when the average power corresponding to the distance library b is greater than a preset signal-to-noise ratio threshold value, calculating the speed at the distance library b according to the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse in the staggered PRT sequence and the initial phase of the second pulse in the staggered PRT sequence.
4. The method of claim 3, wherein the average power corresponding to the distance bin b is calculated according to equation (7):
wherein p (b) is the average power corresponding to the distance library b, Xt23(b)2kAnd the second autocorrelation signal is corresponding to the kth second pulse echo signal.
5. The method of claim 1, wherein the distance bin b corresponds to a distance greater than a maximum unambiguous distance corresponding to a second pulse, and wherein the PRT corresponding to the first pulse is less than the PRT corresponding to the second pulse;
said calculating a velocity at said range bin b from said first pulse echo signal, said second pulse echo signal, an initial phase of a first pulse in said staggered PRT sequence, and an initial phase of a second pulse in said staggered PRT sequence, comprising:
correspondingly, according to the initial phase corresponding to each first pulse in the staggered PRT sequence, each first pulse echo signal is coherent to the corresponding first pulse, and a first coherent signal corresponding to each first pulse echo signal is obtained;
correspondingly, according to the initial phase corresponding to each second pulse in the staggered PRT sequence, each second pulse echo signal is coherent to the corresponding second pulse, and a second coherent signal corresponding to each second pulse echo signal is obtained;
calculating a first autocorrelation phase from each of the first coherent signals and each of the second coherent signals; calculating a first radial velocity from the first autocorrelation phase;
calculating a second autocorrelation phase from each of said second coherent signals and each of said first coherent signals; calculating a second radial velocity according to the second autocorrelation phase;
calculating the speed at the distance bin b according to the first radial speed and the second radial speed.
6. The method of claim 5, wherein the first coherent signal is calculated according to equation (8):
wherein, X't22(b)2kA first coherent signal, x, corresponding to the kth first pulse echo signalt22(b)2kIs IQ complex number, a, of the k-th first pulse echo signal2k-1The initial phase complex number of the first pulse corresponding to the kth first pulse echo signal; n represents the sampling times of the first pulse echo signal;
the second coherent signal is calculated according to equation (9):
wherein, X't11(b)2k-1A second coherent signal, x, corresponding to the kth second pulse echo signalt11(b)2k-1Is IQ complex number, a, of the kth second pulse echo signal2k-2The initial phase complex number of the second pulse corresponding to the kth second pulse echo signal; n represents the sampling times of the second pulse echo signal;
the first autocorrelation phase is calculated according to equation (10):
wherein,
is a first autocorrelation phase, X't22(b)2kIs a first coherent signal, X 'corresponding to the k-th first pulse echo signal't11(b)2k+1A second coherent signal corresponding to the (k + 1) th second pulse echo signal; n represents the sampling times of the first pulse echo signal and the second pulse echo signal respectively;
the first radial velocity is calculated according to equation (11):
wherein, v't22(b) In the case of a first radial velocity,
for the first autocorrelation phase, PRT1 is the pulse repetition time corresponding to the first pulse, λ is the radar wavelength;
the second autocorrelation phase is calculated according to equation (12):
wherein,
is a second autocorrelation phase, X't11(b)2k-1Is a second coherent signal, X 'corresponding to the kth second pulse echo signal't22(b)2kA first coherent signal corresponding to the (k + 1) th first pulse echo signal; n represents the sampling times of the first pulse echo signal and the second pulse echo signal respectively;
the first radial velocity is calculated according to equation (13):
wherein, v't11(b) In order to be the second radial velocity,
for the second autocorrelation phase, PRT2 is the pulse repetition time for the second pulse.
7. The method of claim 5, further comprising:
calculating a first autocorrelation amplitude from the first pulse echo signal; calculating a second autocorrelation amplitude from the first coherent signal;
calculating a third autocorrelation amplitude from the second pulse echo signal; calculating a fourth autocorrelation amplitude from the second coherent signal;
when the second autocorrelation amplitude is greater than the first autocorrelation amplitude and the fourth autocorrelation amplitude is greater than the third autocorrelation amplitude, performing the calculating of the velocity at the range bin b from the first pulse echo signal, the second pulse echo signal, the initial phase of the first pulse in the staggered PRT sequence, and the initial phase of the second pulse in the staggered PRT sequence.
8. The method of claim 7, wherein the first autocorrelation amplitude is calculated according to equation (14):
wherein m ist21(b) Is the first autocorrelation amplitude, Xt22(b)2kAnd Xt22(b)2k-2First autocorrelation signals corresponding to two adjacent first pulse echo signals;
the second autocorrelation amplitude is calculated according to equation (15):
wherein m't21(b) Is a second autocorrelation amplitude, X't22(b)2kAnd X't22(b)2k-2First coherent signals corresponding to two adjacent first pulse echo signals;
the third autocorrelation amplitude is calculated according to equation (16):
wherein m ist11(b) Is the third autocorrelation amplitude, Xt11(b)2k-1And Xt11(b)2k+1Second autocorrelation signals corresponding to two adjacent second pulse echo signals;
the fourth autocorrelation amplitude is calculated according to equation (17):
wherein m't11(b) Is a fourth autocorrelation amplitude, X't11(b)2k-1And X't11(b)2k+1And the second coherent signals correspond to two adjacent second pulse echo signals.
9. Method according to claim 1 or 5, wherein said calculating a velocity at said distance bin b from said first radial velocity and said second radial velocity comprises:
and calculating the speed at the distance library b by using a remainder theorem according to the first radial speed and the second radial speed.
10. A radar speed measuring device, characterized in that the device comprises:
the acquisition module is used for acquiring a first pulse echo signal and a second pulse echo signal which are adjacent to each other on the distance library b; the first pulse echo signal corresponds to a first pulse in a staggered pulse repetition time, PRT, sequence, and the second pulse echo signal corresponds to a second pulse in the staggered PRT sequence; the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the staggered PRT sequence;
a calculating module, configured to calculate a velocity at the distance bin b according to the first pulse echo signal, the second pulse echo signal, an initial phase of a first pulse in the staggered PRT sequence, and an initial phase of a second pulse in the staggered PRT sequence;
the distance corresponding to the distance library b is greater than the maximum unambiguous distance corresponding to the first pulse and smaller than the maximum unambiguous distance corresponding to the second pulse, and the PRT corresponding to the first pulse is smaller than the PRT corresponding to the second pulse;
the calculation module is specifically configured to:
correspondingly, according to the initial phase corresponding to each first pulse in the staggered PRT sequence, each first pulse echo signal is coherent to the corresponding first pulse, and a first coherent signal corresponding to each first pulse echo signal is obtained;
correspondingly calculating second autocorrelation signals corresponding to the second pulse echo signals according to the initial phases corresponding to the second pulses in the staggered PRT sequence and the second pulse echo signals;
calculating a first autocorrelation phase from each of said first coherent signals and each of said second autocorrelation signals; calculating a first radial velocity from the first autocorrelation phase;
calculating a second autocorrelation phase from each of said second autocorrelation signals and each of said first coherent signals; calculating a second radial velocity according to the second autocorrelation phase;
calculating the speed at the distance bin b according to the first radial speed and the second radial speed.
11. The apparatus of claim 10, wherein the distance bin b corresponds to a distance greater than a maximum unambiguous distance corresponding to a second pulse, and wherein the PRT corresponding to the first pulse is less than the PRT corresponding to the second pulse;
the calculation module is specifically configured to:
correspondingly, according to the initial phase corresponding to each first pulse in the staggered PRT sequence, each first pulse echo signal is coherent to the corresponding first pulse, and a first coherent signal corresponding to each first pulse echo signal is obtained;
correspondingly, according to the initial phase corresponding to each second pulse in the staggered PRT sequence, each second pulse echo signal is coherent to the corresponding second pulse, and a second coherent signal corresponding to each second pulse echo signal is obtained;
calculating a first autocorrelation phase from each of the first coherent signals and each of the second coherent signals; calculating a first radial velocity from the first autocorrelation phase;
calculating a second autocorrelation phase from each of said second coherent signals and each of said first coherent signals; calculating a second radial velocity according to the second autocorrelation phase;
calculating the speed at the distance bin b according to the first radial speed and the second radial speed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811495780.6A CN109597060B (en) | 2018-12-07 | 2018-12-07 | Radar speed measurement method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811495780.6A CN109597060B (en) | 2018-12-07 | 2018-12-07 | Radar speed measurement method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109597060A CN109597060A (en) | 2019-04-09 |
| CN109597060B true CN109597060B (en) | 2021-06-25 |
Family
ID=65961390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811495780.6A Active CN109597060B (en) | 2018-12-07 | 2018-12-07 | Radar speed measurement method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109597060B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114019495B (en) * | 2021-10-27 | 2024-05-31 | 海信集团控股股份有限公司 | Method and related device for determining maximum non-fuzzy speed of millimeter wave radar |
| CN114779228B (en) * | 2022-03-31 | 2023-10-24 | 南京隼眼电子科技有限公司 | Target ranging method, device and storage medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997042520A1 (en) * | 1996-05-08 | 1997-11-13 | Andrews Grealie A Jr | Radar/sonar system concept for extended range-doppler coverage |
| CN101017203A (en) * | 2006-09-26 | 2007-08-15 | 南京大桥机器有限公司 | Portable X wave range Doppler weather radar signal processing method and device thereof |
| CN101320086A (en) * | 2008-06-27 | 2008-12-10 | 北京航空航天大学 | Echo signal processing device and method of a Doppler speed measuring lidar |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6081221A (en) * | 1998-08-27 | 2000-06-27 | Zrnic; Dusan S. | Signal processing and systematic phase coding for mitigation of range and velocity ambiguities in Doppler weather radars |
| NL1020763C2 (en) * | 2002-06-05 | 2003-12-08 | Thales Nederland Bv | Method and system for deconvolving a signal sampled with an irregular PRT, and its application possibilities. |
| CN101738601B (en) * | 2009-11-27 | 2012-06-20 | 西安电子科技大学 | System and method for measuring speed of locomotive based on radar near field echo power spectrum characteristics |
| CN103064068A (en) * | 2012-12-31 | 2013-04-24 | 南昌大学 | Bi-phase inter-pulse coded pulse train radar waveform with batch-to-batch diverse pulse recurrence interval (PRI) |
| US9310480B2 (en) * | 2013-05-08 | 2016-04-12 | Jorn Sierwald | Method and arrangement for removing ground clutter |
| CN104007435B (en) * | 2014-04-24 | 2016-08-24 | 北京航空航天大学 | A kind of accurate speed-measuring method based on intermediate frequency adjacent echoes phase contrast |
| CN104950292B (en) * | 2015-07-23 | 2017-09-15 | 北京敏视达雷达有限公司 | A kind of second trip echo recognition methods of weather radar and device |
| CN106338721B (en) * | 2016-08-23 | 2019-03-29 | 西安电子科技大学 | Aerial at the uniform velocity detection method of small target based on multiframe echo correlative accumulation |
| CN108828602B (en) * | 2018-03-06 | 2021-03-12 | 北京大学 | Signal processing method for eliminating velocity ambiguity in pulse phase dry method velocity measurement |
-
2018
- 2018-12-07 CN CN201811495780.6A patent/CN109597060B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997042520A1 (en) * | 1996-05-08 | 1997-11-13 | Andrews Grealie A Jr | Radar/sonar system concept for extended range-doppler coverage |
| CN101017203A (en) * | 2006-09-26 | 2007-08-15 | 南京大桥机器有限公司 | Portable X wave range Doppler weather radar signal processing method and device thereof |
| CN101320086A (en) * | 2008-06-27 | 2008-12-10 | 北京航空航天大学 | Echo signal processing device and method of a Doppler speed measuring lidar |
Non-Patent Citations (2)
| Title |
|---|
| Using the Existing Spectral Clutter Filter With the Nonuniformly Spaced Time Series Data in Weather Radar;Svetlana M等;《IEEE GEOSCIENCE AND REMOTE SENSING LETTERS》;20080731;第5卷(第3期);全文 * |
| 参差PRT退速度模糊在X波段天气雷达中的应用;王旭等;《计算机工程与应用》;20081231;摘要，第4节 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109597060A (en) | 2019-04-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6564472B2 (en) | Vehicle radar system | |
| EP3425419B1 (en) | A method and a system for localization and monitoring of living beings | |
| JP3699450B2 (en) | Method and apparatus for measuring distance and relative velocity of distant objects | |
| JP5595496B2 (en) | Radar equipment | |
| US9465108B1 (en) | System and method for target doppler estimation and range bias compensation using high duty cycle linear frequency modulated signals | |
| KR20150094240A (en) | Apparatus and method of detecting target using radar | |
| CN103777178B (en) | A kind of synchronous error compensation method, equipment and system | |
| JP5656505B2 (en) | Radar equipment | |
| JP2010197178A (en) | Pulse compression device | |
| KR101125276B1 (en) | Method and Apparatus for Detecting Range and Velocity of Target by Using Radar and Computer Readable Recording Medium for Recording Program Therefor | |
| CN109597060B (en) | Radar speed measurement method and device | |
| JP4507245B2 (en) | Time measurement system, object detection system, shift measurement method | |
| KR20120043281A (en) | Apparatus and method of measuring distance and velocity of moving object using pulse doppler radar | |
| CN115128592A (en) | Debris flow surface flow velocity monitoring method and system | |
| JP4702117B2 (en) | Pulse radar apparatus and distance measuring method | |
| KR102165799B1 (en) | System and Method for calculating parameters for target detection in FMCW radar system | |
| Schroeder et al. | X-band FMCW radar system with variable chirp duration | |
| KR100902560B1 (en) | Apparatus and method for generating threat alert of tracking radar during search | |
| JP5757303B2 (en) | Underwater acoustic positioning system | |
| JP6184220B2 (en) | Radar system, radar apparatus and radar signal processing apparatus | |
| JP4754292B2 (en) | Radar equipment | |
| US20070052579A1 (en) | Radar system | |
| KR101122523B1 (en) | Method and apparatus for vehicle uwb radar signal processing distinguishing plural vehicle | |
| JP6610224B2 (en) | Bistatic active sonar device and its receiver | |
| JP3881078B2 (en) | Frequency estimation method, frequency estimation device, Doppler sonar and tidal meter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |