CN112630778A - Ultrahigh sound speed target imaging method - Google Patents

Ultrahigh sound speed target imaging method Download PDF

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CN112630778A
CN112630778A CN202011274953.9A CN202011274953A CN112630778A CN 112630778 A CN112630778 A CN 112630778A CN 202011274953 A CN202011274953 A CN 202011274953A CN 112630778 A CN112630778 A CN 112630778A
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CN112630778B (en
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庄志洪
俞雷
沈晓峰
庄玉玲
杨苏成
常多
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Nanjing University of Science and Technology
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    • 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
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Abstract

The invention discloses an ultrahigh sound speed target imaging method which is real, reliable, simple and feasible. The method comprises the following steps: (10) processing subsonic target data: processing and storing the actually measured subsonic target total echo data into a two-dimensional sampling matrix of each frame; (20) and (3) moving one-dimensional distance imaging of the subsonic target: extracting two frames of echo data to be respectively sent to a two-dimensional matrix, and obtaining two frames of motion distance images through IFFT transformation and image splicing; (30) subsonic target still imaging: carrying out speed compensation on the target echo, and obtaining a still one-dimensional distance image of the subsonic target through IFFT conversion and image splicing again; (40) equivalent hypersonic motion one-dimensional distance image: equivalent two frames of ultrahigh sound speed target motion one-dimensional distance images according to the high speed target information; (50) static one-dimensional distance imaging of the hypersonic target: and performing speed compensation, IFFT (inverse fast Fourier transform) conversion and image splicing on the echo of the hypersonic target to obtain a static one-dimensional distance image.

Description

Ultrahigh sound speed target imaging method
Technical Field
The invention belongs to the technical field of guidance fuses, and particularly relates to an ultrahigh-sound-speed target imaging method.
Background
The high resolution range image is the vector sum of the target scattering point echo obtained by using broadband radar signal projected on the radar ray, and it provides the distribution information of target scattering point along the distance direction.
However, the prior art has problems that: when most high-resolution radars are used for actually measuring targets, the motion speed of most targets is in a subsonic speed state, and the ultrahigh-sound-speed targets are difficult to contact, so that people can slowly understand in a ultrahigh-sound-speed high-resolution range profile test part, and cannot explore the imaging condition of the targets in the ultrahigh-sound-speed motion state and the difference and connection between the targets and the subsonic-speed target profile.
Disclosure of Invention
The invention aims to provide a hypersonic target imaging method which is real, reliable, simple and feasible.
The technical solution for realizing the purpose of the invention is as follows:
a hypersonic target imaging method comprises the following steps:
(10) processing subsonic target data: processing the actually measured subsonic target total echo data into echo data point sets of each frame and storing the echo data point sets into a two-dimensional sampling matrix of each frame;
(20) and (3) moving one-dimensional distance imaging of the subsonic target: extracting two frames of echo data to be respectively sent to a two-dimensional matrix, and obtaining two frames of motion distance images through IFFT transformation and image splicing;
(30) subsonic target still imaging: setting an echo distance gate, measuring target speed values under two frames according to two frames of motion distance images and an entropy speed measurement method, performing speed compensation on target echoes, and obtaining a subsonic target static one-dimensional distance image through IFFT (inverse fast Fourier transform) and image splicing;
(40) equivalent hypersonic motion one-dimensional distance image: setting a hypersonic speed value, respectively calculating corresponding positions and amplitudes of hypersonic speed targets corresponding to two frames of static distance images, multiplying static target echoes by a high-speed equivalent factor to obtain hypersonic speed phase information, and equivalently obtaining the two frames of hypersonic speed target motion one-dimensional distance images according to the high-speed target positions, amplitudes and phase information;
(50) static one-dimensional distance imaging of the hypersonic target: measuring the velocity of the hypersonic speed under the two frames of motion distance images by an entropy velocity measurement method, performing velocity compensation on the echo of the hypersonic speed target, and obtaining the static one-dimensional distance image of the hypersonic speed target of the two frames by IFFT (inverse fast Fourier transform) and an image splicing algorithm. Compared with the prior art, the invention has the following remarkable advantages:
1. equivalent reality: according to the imaging shape of the subsonic target measured at present, the noise and the background clutter of the surrounding environment are equivalent to the background noise and the clutter of the hypersonic environment and the imaging quality.
2. The realization is simple: according to the real environment and the subsonic speed target, imaging corresponding to the ultrahigh sound speed is simulated, the implementation is simple, and the difficulty degree of actual testing is greatly reduced.
The invention is described in further detail below with reference to the figures and the detailed description.
Drawings
Fig. 1 is a main flowchart of the hypersonic target imaging method of the present invention.
Fig. 2 is a flowchart of the one-dimensional distance imaging step of the subsonic target movement in fig. 1.
Fig. 3 is a flowchart of the still imaging step of the subsonic target of fig. 1.
FIG. 4 is a flowchart of the equivalent hypersonic motion one-dimensional distance image step of FIG. 1.
FIG. 5 is a flowchart of the stationary one-dimensional range imaging procedure for a hypersonic target.
Fig. 6 shows a one-dimensional distance image after IFFT and image stitching.
FIG. 7 is a still image of a subsonic target.
Fig. 8 is a one-dimensional distance image of equivalent hypersonic motion.
FIG. 9 is a stationary one-dimensional range imaging of a hypersonic target.
Detailed Description
As shown in fig. 1, the hypersonic target imaging method of the present invention includes the following steps:
(10) processing subsonic target data: processing the actually measured subsonic target total echo data into echo data point sets of each frame and storing the echo data point sets into a two-dimensional sampling matrix of each frame;
(20) and (3) moving one-dimensional distance imaging of the subsonic target: extracting two frames of echo data to be respectively sent to a two-dimensional matrix, and obtaining two frames of motion distance images through IFFT transformation and image splicing;
as shown in fig. 2, the (20) subsonic target echo signal processing step includes:
(21) inverse Fourier transform: performing IFFT calculation on N data of each line of the echo matrix S (m, N) of the two frames so as to obtain a distance image redundant matrix of a target;
(22) distance image splicing: and splicing the two-dimensional redundant matrixes of the two frames of range profiles into a one-dimensional range profile according to a maximum value splicing algorithm so as to obtain the motion one-dimensional range profile of the two frames of targets, as shown in fig. 6.
(30) Subsonic target still imaging: setting an echo distance gate, measuring target speed values under two frames according to two frames of motion distance images and an entropy speed measurement method, performing speed compensation on target echoes, and obtaining a subsonic target static one-dimensional distance image through IFFT (inverse fast Fourier transform) and image splicing;
as shown in fig. 3, the (30) subsonic target still imaging step includes:
(31) obtaining the static one-dimensional distance imaging of the subsonic target: the echo data matrix S (m, n) is multiplied by the following phase factors and subjected to IFFT transformation and range image stitching to obtain a static one-dimensional range image, as shown in FIG. 7, wherein
Figure BDA0002778791780000037
Velocity values estimated for entropy velocimetry
Figure BDA0002778791780000031
(32) Entropy calculation: firstly, setting different speed estimation values, solving the entropy of the motion one-dimensional distance image of the two frames of targets, solving the minimum entropy of the two frames of images according to the following formula, wherein the speed estimation value is the measured target motion speed value:
Figure BDA0002778791780000032
Figure BDA0002778791780000033
Figure BDA0002778791780000034
V＝min(Hn(A,Vn))
in the formula, Hn(A,Vn) To estimate a speed VnThe obtained entropy, A (i), is a one-dimensional range profile sequence of the target, N is the number of pulses, and V is the estimated velocity value when the entropy is minimum.
(40) Equivalent hypersonic motion one-dimensional distance image: setting a hypersonic speed value, respectively calculating corresponding positions and amplitudes of hypersonic speed targets corresponding to two frames of static distance images, multiplying static target echoes by a high-speed equivalent factor to obtain hypersonic speed phase information, and equivalently obtaining the two frames of hypersonic speed target motion one-dimensional distance images according to the high-speed target positions, amplitudes and phase information;
as shown in fig. 4, the step of (40) equivalent super-high speed motion one-dimensional distance image comprises:
(41) calculating position information: calculating the target time displacement of two frames
Figure BDA0002778791780000035
tRIs the first frame time position, V is the hypersonic velocity, TuFor unambiguous time lengths, N is a pulseString length, TsDv is the velocity resolution for the sampling time;
(42) calculating phase information: computing hypersonic phase information for two frame targets
Figure BDA0002778791780000036
V is hypersonic velocity, TrIs the pulse period, fnFor stepping the frequency, TsSampling time, C is light speed, m is the number of sampling units, and n is the stepping length;
(43) calculating amplitude information: respectively calculating the total attenuation factors of two frames of targets
Figure BDA0002778791780000041
Wherein the attenuation coefficient
Figure BDA0002778791780000042
Figure BDA0002778791780000043
For a reduced value of received power, PrFor the received power value, dR is the length of motion;
(44) calculating a distance image: and calculating target echoes of two frames according to the obtained displacement information, phase information and attenuation information, and performing IFFT (inverse fast Fourier transform) and image splicing to obtain a motion one-dimensional distance image of the corresponding hypersonic target, as shown in FIG. 8.
(50) Static one-dimensional distance imaging of the hypersonic target: measuring the velocity of the hypersonic speed under the two frames of motion distance images by an entropy velocity measurement method, performing velocity compensation on the echo of the hypersonic speed target, and obtaining the static one-dimensional distance image of the hypersonic speed target of the two frames by IFFT (inverse fast Fourier transform) and an image splicing algorithm.
As shown in fig. 5, the (50) step of static one-dimensional range imaging of the ultra-high speed target includes:
(51) entropy calculation: firstly, setting different hypersonic speed estimation values, solving the entropy of the motion one-dimensional distance image of the two frames of targets, solving the minimum entropy of the two frames of images according to the following formula, wherein the speed estimation value is the measured target hypersonic speed motion speed value:
Figure BDA0002778791780000044
Figure BDA0002778791780000045
Figure BDA0002778791780000046
V＝min(Hn(A,Vn))
in the formula, Hn(A,Vn) To estimate a speed VnThe obtained entropy, A (i) is a one-dimensional range profile sequence of the target, N is the number of pulses, and V is an estimated hypersonic velocity value when the entropy is minimum;
(52) obtaining the static one-dimensional distance imaging of the hypersonic target: the hypersonic echo data matrix S (m, n) is multiplied by the following phase factor and subjected to IFFT transformation and range image splicing to obtain a static one-dimensional range image, as shown in FIG. 9, wherein
Figure BDA0002778791780000048
For the hypersonic velocity values estimated by the entropy velocimetry method,
Figure BDA0002778791780000047
the scheme of the invention is used for realizing the imaging condition that different targets move at ultrahigh sound speed in different environments, provides an idea for performing ultrahigh sound speed experiment imaging test, solves the problem of difficult experiment implementation, and effectively improves the experiment efficiency.

Claims (5)

1. A hypersonic target imaging method is characterized by comprising the following steps:
(10) processing subsonic target data: processing the actually measured subsonic target total echo data into echo data point sets of each frame and storing the echo data point sets into a two-dimensional sampling matrix of each frame;
(20) and (3) moving one-dimensional distance imaging of the subsonic target: extracting two frames of echo data to a two-dimensional matrix respectively, and obtaining two frames of motion distance images through LFFT transformation and image splicing;
(30) subsonic target still imaging: setting an echo distance gate, measuring target speed values under two frames according to two frames of motion distance images and an entropy speed measurement method, performing speed compensation on target echoes, and obtaining a subsonic target static one-dimensional distance image through IFFT (inverse fast Fourier transform) and image splicing;
(40) equivalent hypersonic motion one-dimensional distance image: setting a hypersonic speed value, respectively calculating corresponding positions and amplitudes of hypersonic speed targets corresponding to two frames of static distance images, multiplying static target echoes by a high-speed equivalent factor to obtain hypersonic speed phase information, and equivalently obtaining the two frames of hypersonic speed target motion one-dimensional distance images according to the high-speed target positions, amplitudes and phase information;
(50) static one-dimensional distance imaging of the hypersonic target: measuring the velocity of the hypersonic speed under the two frames of motion distance images by an entropy velocity measurement method, performing velocity compensation on the echo of the hypersonic speed target, and obtaining the static one-dimensional distance image of the hypersonic speed target of the two frames by IFFT (inverse fast Fourier transform) and an image splicing algorithm.
2. The hypersonic target imaging method as set forth in claim 1, wherein the (20) subsonic target echo signal processing step includes:
(21) inverse Fourier transform: performing IFFT calculation on N data of each line of the echo matrix S (m, N) of the two frames so as to obtain a distance image redundant matrix of a target;
(22) distance image splicing: splicing two-frame range profile two-dimensional redundant matrixes into a one-dimensional range profile according to the following maximum value splicing algorithm to obtain the motion one-dimensional range profile of two frames of targets
Qs＝fix(mLTs/Tu)
ne＝N×mod(mLTs/Tu，1)
sndr＝QsN+mod(ne-W+N，N)
Wp＝NTP/Tu
m＝mL，mL+1，...，mH-1，mH
q＝fix[(mTs-dt)/Tu]+1
ne＝N×mod(mTs/Tu，1)
ns＝mod(ns-W+N，N)
qs＝q×N
Figure FDA0002778791770000021
Figure FDA0002778791770000022
In the formula, QsIs m atLA sampling point mLTsLength of the ambiguity time, N being the length of the burst, TsFor sample time, dt is the temporal resolution, neFor the end position corresponding to the sampling point, nsIs the starting position, sndr is the starting position, W is the effective range image width, TuAnd for a non-fuzzy distance window, Z is a distance image storage array extracted after redundancy removal, and S (m, n) is an original distance image redundancy matrix.
3. The hypersonic target imaging method as set forth in claim 2, wherein the (30) subsonic target still imaging step includes:
(31) obtaining the static one-dimensional distance imaging of the subsonic target: multiplying the echo data matrix S (m, n) by the following phase factor and performing IFFT transformation and range image splicing to obtain a static one-dimensional range image, wherein
Figure FDA0002778791770000024
Velocity values estimated for entropy velocimetry
Figure FDA0002778791770000023
(32) Entropy calculation: firstly, setting different speed estimation values, solving the entropy of the motion one-dimensional distance image of the two frames of targets, solving the minimum entropy of the two frames of images according to the following formula, wherein the speed estimation value is the measured target motion speed value:
Figure FDA0002778791770000031
Figure FDA0002778791770000032
Figure FDA0002778791770000033
V＝min(Hn(A，Vn))
in the formula, Hn(A，Vn) To estimate a speed VnThe obtained entropy, A (i), is a one-dimensional range profile sequence of the target, N is the number of pulses, and V is the estimated velocity value when the entropy is minimum.
4. The hypersonic target imaging method of claim 3, wherein said (40) equivalent hypersonic motion one-dimensional range imaging step comprises:
(41) calculating position information: calculating the target time displacement of two frames
Figure FDA0002778791770000034
tRIs the first frame time position, V is the hypersonic velocity, TuFor unambiguous time lengths, N is a pulseString length, TsDv is the velocity resolution for the sampling time;
(42) calculating phase information: computing hypersonic phase information for two frame targets
Figure FDA0002778791770000035
V is hypersonic velocity, TrIs the pulse period, fnFor stepping the frequency, TsSampling time, C is light speed, m is the number of sampling units, and n is the stepping length;
(43) calculating amplitude information: respectively calculating the total attenuation factors of two frames of targets
Figure FDA0002778791770000036
Wherein the attenuation coefficient
Figure FDA0002778791770000037
Figure FDA0002778791770000038
For a reduced value of received power, PrFor the received power value, dR is the length of motion;
(44) calculating a distance image: and calculating target echoes of two frames according to the obtained displacement information, phase information and attenuation information, and performing IFFT (inverse fast Fourier transform) and image splicing to obtain a motion one-dimensional distance image of the corresponding hypersonic target.
5. The hypersonic target imaging method of claim 4, wherein said (50) hypersonic target stationary one-dimensional range imaging step comprises:
(51) entropy calculation: firstly, setting different hypersonic speed estimation values, solving the entropy of the motion one-dimensional distance image of the two frames of targets, solving the minimum entropy of the two frames of images according to the following formula, wherein the speed estimation value is the measured target hypersonic speed motion speed value:
Figure FDA0002778791770000041
Figure FDA0002778791770000042
Figure FDA0002778791770000043
V＝min(Hn(A，Vn))
in the formula, Hn(A，Vn) To estimate a speed VnThe obtained entropy, A (i) is a one-dimensional range profile sequence of the target, N is the number of pulses, and V is an estimated hypersonic velocity value when the entropy is minimum;
(52) obtaining the static one-dimensional distance imaging of the hypersonic target: multiplying the hypersonic echo data matrix S (m, n) by the following phase factor and performing IFFT transformation and range image splicing to obtain a static one-dimensional range image, wherein
Figure FDA0002778791770000044
For the hypersonic velocity values estimated by the entropy velocimetry method,
Figure FDA0002778791770000045
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102590812A (en) * 2012-01-13 2012-07-18 西安电子科技大学 SAR (synthetic aperture radar) real-time imaging method based on frequency modulated continuous wave
CN105068072A (en) * 2015-07-22 2015-11-18 北京环境特性研究所 Speed compensation method of one-dimensional distance images of moving object
CN106872974A (en) * 2017-01-23 2017-06-20 西安电子科技大学 High-precision motion target imaging method based on hypersonic platform Two-channels radar
CN111007503A (en) * 2019-09-03 2020-04-14 西安电子科技大学 Moving target focusing and positioning method and system based on frequency spectrum accurate positioning

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102590812A (en) * 2012-01-13 2012-07-18 西安电子科技大学 SAR (synthetic aperture radar) real-time imaging method based on frequency modulated continuous wave
CN105068072A (en) * 2015-07-22 2015-11-18 北京环境特性研究所 Speed compensation method of one-dimensional distance images of moving object
CN106872974A (en) * 2017-01-23 2017-06-20 西安电子科技大学 High-precision motion target imaging method based on hypersonic platform Two-channels radar
CN111007503A (en) * 2019-09-03 2020-04-14 西安电子科技大学 Moving target focusing and positioning method and system based on frequency spectrum accurate positioning

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
吴晓芳 等: "《频率步进雷达目标运动参数估计的新方法》", 《信号处理》 *

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