CN112346058A - Imaging method for improving signal-to-noise ratio of high-speed SAR platform based on continuous pulse coding - Google Patents

Imaging method for improving signal-to-noise ratio of high-speed SAR platform based on continuous pulse coding Download PDF

Info

Publication number
CN112346058A
CN112346058A CN202011190783.6A CN202011190783A CN112346058A CN 112346058 A CN112346058 A CN 112346058A CN 202011190783 A CN202011190783 A CN 202011190783A CN 112346058 A CN112346058 A CN 112346058A
Authority
CN
China
Prior art keywords
signal
echo
pulse train
pulse
echoes
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.)
Granted
Application number
CN202011190783.6A
Other languages
Chinese (zh)
Other versions
CN112346058B (en
Inventor
李亚超
魏婧怡
崔嘉禾
徐刚锋
郭亮
熊涛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xidian University
Original Assignee
Xidian University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Xidian University filed Critical Xidian University
Priority to CN202011190783.6A priority Critical patent/CN112346058B/en
Publication of CN112346058A publication Critical patent/CN112346058A/en
Application granted granted Critical
Publication of CN112346058B publication Critical patent/CN112346058B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
    • G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
    • G01S13/9004—SAR image acquisition techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section

Landscapes

  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

本发明公开了一种基于连续脉冲编码提升高速SAR平台信噪比的成像方法，主要解决现有技术无法在高速SAR平台成像的问题。其实现方案是：设计脉冲串信号，并重复发射该脉冲串信号；根据发射的脉冲串信号得到原始的混叠回波信号；根据发射的脉冲串信号形式构建多元线性方程组：从多元线性方程组中按照确定的步长选取多个方程数量相同的子方程组，进行完整回波信号求解，得到解混叠后的回波信号；对解混叠后的回波信号进行均匀分组并同组叠加，将叠加后的回波信号按照等效的脉冲重复频率进行SAR成像。本发明能提高方位采样率，消除回波的方位频谱混叠，实现在高速平台的成像，可用于地形测绘、海洋观测、灾情预报、农作物评估及天体观测。

Figure 202011190783

The invention discloses an imaging method for improving the signal-to-noise ratio of a high-speed SAR platform based on continuous pulse coding, which mainly solves the problem that the prior art cannot image the high-speed SAR platform. The implementation scheme is: design a pulse train signal, and transmit the pulse train signal repeatedly; obtain the original aliased echo signal according to the transmitted pulse train signal; construct a multivariate linear equation system according to the form of the transmitted pulse train signal: from the multivariate linear equation In the group, multiple sub-equations with the same number of equations are selected according to the determined step size, and the complete echo signal is solved to obtain the de-aliased echo signal; the de-aliased echo signals are evenly grouped and grouped together. Superimpose, and perform SAR imaging on the superimposed echo signals according to the equivalent pulse repetition frequency. The invention can improve the azimuth sampling rate, eliminate the azimuth spectrum aliasing of echoes, realize imaging on a high-speed platform, and can be used for terrain mapping, ocean observation, disaster forecast, crop evaluation and celestial body observation.

Figure 202011190783

Description

Imaging method for improving signal-to-noise ratio of high-speed SAR platform based on continuous pulse coding
Technical Field
The invention belongs to the technical field of digital signal processing, and particularly relates to an imaging method for improving the signal-to-noise ratio of an image of a high-speed SAR platform, which can be used for topographic mapping, ocean observation, disaster prediction, crop evaluation and celestial body observation.
Background
The synthetic aperture radar SAR is a full-time and all-weather remote detection means and has the capability of imaging a target. The signal-to-noise ratio SNR of the radar image is one of important indicators for measuring the imaging quality of the radar image, and directly determines whether accurate target information can be obtained from the radar image. In military applications, battlefield reconnaissance, target identification, ground attack, etc., and in civilian applications, terrain mapping, ocean observation, disaster prediction, crop assessment, celestial observation, etc., are available.
Wang Shifei et al put forward a pulse coding theory in a radar pulse coding theory method and application [ J ] radar science report, 2019,8(1): 1-16. doi:10.12000/JR19023 ], and improve the signal-to-noise ratio of a radar image by improving the duty ratio of a transmitted signal. The method comprises the steps of converting a monopulse signal transmitted in an original pulse repetition period into a group of long pulse train signals containing a plurality of monopulses, resolving and processing aliasing echoes in each receiving window to recover complete echoes corresponding to the monopulse signals as much as possible, and finally performing coherent superposition on the recovered complete echoes to achieve the purpose of improving the signal-to-noise ratio of radar echoes. The method has the following defects:
the recovered multiple groups of complete echoes need to transmit overlong pulse signals, and the longer the transmitted signals are, the larger the pulse train repetition period is, namely the lower the pulse train repetition frequency is, so that the method applied to a high-speed SAR platform can cause aliasing of the azimuth frequency spectrum of the echoes due to the fact that the pulse train repetition frequency is not high enough according to the sampling theorem, and the imaging effect is poor.
Disclosure of Invention
The invention aims to provide an imaging method for improving the signal-to-noise ratio of a high-speed SAR platform based on continuous pulse coding aiming at the defects in the prior art so as to equivalently improve the azimuth sampling rate, eliminate the azimuth spectrum aliasing of echoes and improve the imaging effect.
The technical idea of the invention is as follows: the method comprises the steps of continuously transmitting pulse train signals by taking the length of a pulse train as a period, selecting receiving windows which are periodically arranged to solve aliasing echoes, taking complete echo signals recovered by each group as one-time slow sampling echoes of a radar, and accurately imaging a target while obtaining a high signal-to-noise ratio by a high-speed SAR platform.
According to the above thought, the implementation steps of the invention include the following:
(1) designing a pulse train signal, and repeatedly transmitting the pulse train signal, wherein the repetition period is the width of the pulse train signal, each pulse train signal comprises a plurality of single pulse signals, and gaps among the single pulse signals are receiving windows;
(2) simulating SAR echo signals according to the transmitted pulse train signals to obtain original aliasing echo signals;
(3) constructing a multi-element linear equation set according to the form of the transmitted pulse train signal: where L is an observation matrix of each receive window, X is a set of all complete echoes that need to be solved, and R is an aliased echo signal of each receive window;
(4) selecting a plurality of sub-equation sets with the same equation quantity from the multi-element linear equation set established in the step (3) according to the determined step length, and solving the set X of all complete echoes to obtain an echo signal after aliasing resolution;
(5) uniformly grouping and superposing the echo signals after unmixing and superposition in the same group, and carrying out SAR imaging on the superposed echo signals according to equivalent pulse repetition frequency PRF;
compared with the prior art, the invention has the following advantages:
1. equivalently improving the azimuth sampling rate, eliminating the azimuth spectrum aliasing of the echo, and being suitable for a high-speed platform
In the prior art, in order to improve the signal-to-noise ratio of a radar image, a series of single pulse coding signals are adopted, and a next pulse train can be transmitted only after the echo of the last sub-pulse in the current pulse train is received, namely the transmitting frequency of the pulse train cannot be too large, so that for a high-speed platform, the azimuth frequency spectrum of the high-speed platform is subjected to aliasing due to undersampling, and accurate imaging cannot be performed;
the invention adopts a continuous pulse coding method, the pulse train repetition period is the time width of the pulse train, namely, the next pulse train is transmitted after the echo of the last sub-pulse in the current pulse train is received; in addition, the invention equivalently converts a plurality of groups of complete echoes calculated in a pulse train repetition period into sampling echoes of the radar at different azimuth moments, equivalently improves the radar azimuth sampling frequency, simultaneously ensures the signal-to-noise ratio requirement of the SAR image, eliminates azimuth spectrum aliasing caused by undersampling, improves the SAR imaging effect, and can be applied to a high-speed platform.
2. High adaptability
Because the invention designs the pulse train signal composed of S, 0 and-S, for the platforms with different speeds, a plurality of groups of echoes calculated in a pulse train repetition period can be equivalent to the sampling echoes of the radar at different azimuth moments, and partial echoes can be subjected to coherent superposition to improve the signal-to-noise ratio of one-dimensional distance direction, so that the invention has strong adaptability, and can be applied to not only high-speed platforms but also low-speed platforms.
Drawings
FIG. 1 is a flow chart of an implementation of the present invention;
FIG. 2 is a schematic diagram of a continuous pulse encoded signal transmitted in the present invention;
FIG. 3 is a diagram of echoes corresponding to burst encoded signals in the present invention;
FIG. 4 is a block diagram of an echo signal according to the present invention;
FIG. 5 is a schematic diagram of echo azimuth spectral aliasing caused by application of the prior art to a high speed platform;
FIG. 6 is a schematic diagram of the echo azimuth spectrum of the present invention applied to a high-speed platform;
FIG. 7 is a diagram of conventional single pulse imaging results on a high-speed stage;
FIG. 8 is a schematic diagram of the imaging results of the present invention at a high speed stage.
Detailed Description
The following describes in detail specific embodiments and effects of the present invention with reference to the drawings.
Referring to fig. 1, the implementation steps of this example are as follows:
step 1, designing a pulse train signal and repeatedly transmitting the pulse train signal.
The pulse train signal designed by the embodiment is composed of S, 0 and S, wherein S is time width TPThe interval of the chirp signal is fixed to TPOr 2TPI.e. one or two receive windows; s is a phase which adds pi to S, 0 represents a time width TPThe receive window of (1). The pulse train signal has a plurality of groups of permutation and combination forms, the length is designed according to requirements, fig. 2 shows an example of the pulse train signal, and the pulse train signal is represented as follows: S0S0S00S00-S0-S0S00S00S 0S;
the radar repeatedly transmits the pulse train signal to the target with the time width of the pulse train as a period.
And 2, receiving the echo signal of the target scene by the radar.
Because the interval time of the single pulses in the transmitted pulse train signal is very short, the echo corresponding to each single pulse signal is subjected to aliasing, and because the radar adopts a single-channel mode, a target echo cannot be received when the signal is transmitted, part of the echo is shielded by the transmitted single pulse signal, so that the echo is not complete, and the echo signal received by the radar is an incomplete and aliased signal, as shown in fig. 3;
because the imaging processing cannot be directly performed by using the echo in the receiving window due to the imperfection and aliasing of the echo, the complete echo information corresponding to the monopulse needs to be recovered from the aliasing echo of each receiving window.
And 3, constructing a multi-element linear equation set according to the form of the transmitted pulse train signal.
(3a) Let X be the set of all complete echoes to be solved, and because the pitch angle of the beam is limited and the scene width of radar illumination is limited, the length of the scene echo corresponding to a single pulse is limited, i.e. the duration of the scene echo corresponding to a single pulse after reception is limited from the beginning is denoted as T, and N is defined as T/TPIs upwardly-directed integer value of, wherein TPFor the time width of the chirp signal, X is given by TPIs a unit, is divided into N segments and is marked as X ═ X1,X2...Xn...XN]TAs shown in FIG. 4, wherein XnFor the nth echo, N is equal to [1, N ]]；
(3b) The aliased echo signal of each receive window is denoted as R ═ R1,R2...Rm...RM]T，RmFor the aliased echo signal of the mth receive window, M ∈ [1, M]M is the total number of receiving windows, and for the signal example in step 1, M is 13 × nan, and nan is the number of pulse train signals transmitted to the radar in the azimuth direction;
(3c) and (3) obtaining an observation matrix L according to the echo length and the transmitted pulse train signal form:
Figure BDA0002752677460000041
wherein lmnRepresents whether the nth segment of echo X exists in the mth receiving windownIf present, according to XnTaking l as positive and negative of corresponding transmitted monopulsemnIs 1 or-1, if no echo X exists in the mth receiving windownThen l ismnThe value is 0, M is belonged to [1, M]，n∈[1,N]；
(3d) And constructing a linear equation system Y according to the aliasing echo signals R and the observation matrix L of each receiving window:
constructing a linear equation set Y to be expressed as LX-R without considering noise, solving the equation set to obtain a complete echo set X without noise,
when considering noise, a system of linear equations is constructed as: solving the equation set to obtain a complete echo set X under the condition of noise, and simultaneously obtaining the change condition of the noise so as to measure the improvement of the signal-to-noise ratio of the radar;
and 4, resolving a linear equation set of the sub-lines to obtain a complete target echo corresponding to the single pulse signal.
Because the interval of the pulses in each group in the pulse train signal is very small and is in the microsecond level, the echo signals of each sub-pulse in one pulse train repetition period can be assumed to be approximately the same, and the assumption provides possibility for resolving the complete scene echo corresponding to a single pulse from the aliasing echo;
(4a) selecting Q continuous equations from the linear equation set Y, forming a sub-linear equation set lx belonging to Y, which is recorded as Y, and solving x to obtain: x ═ lTl)-1lTr, where Q > ═ N, L is a submatrix extracted row-wise for L, the rank of L is equal to or greater than N, i.e. LTl is a reversible matrix, X is a certain complete echo, X belongs to X, and R is a subvector of R;
(4b) selecting K as a step length, using a sub-linear equation set Y as a reference, sequentially selecting Q continuous equations in the linear equation set Y to form other sub-linear equation sets until all the equations in Y are selected, solving X corresponding to each equation set, and further obtaining a complete echo set X after de-aliasing1Then x, i.e. the radar equivalent pulse repetition frequency PRF is 1/T1. In the selection of T1The PRF is required to be greater than the minimum azimuth sampling rate required by radar imaging.
And 5, carrying out SAR imaging processing on all the recovered complete echoes.
(5a) Arranging the solved complete echoes in sequence according to the corresponding receiving windows;
(5b) and uniformly grouping the arrayed echoes to enable each group to contain num complete echoes, and then performing coherent superposition on the num complete echoes in the same group. The step (4b) easily deduces that the equivalent pulse repetition frequency PRF after the packet superposition is 1/(num × T)1)；
Because the echo in the group is coherent superposition and the noise is incoherent superposition, theoretically, the more the number of the superposed echoes is, the more the signal-to-noise ratio is improved, but as can be known from an equivalent pulse repetition frequency formula, the more the number of the superposed echoes is, the lower the equivalent azimuth sampling rate of the radar is, the problem of spectrum aliasing caused by undersampling of the echo obtained by the high-speed platform radar after solving can be caused, and accurate SAR imaging cannot be performed, so that the number of the echo in the group cannot be too large in the actual imaging process, and the number num of the echo in the group needs to be flexibly selected under the condition of meeting the requirements.
The technical effects of the invention are further explained by simulation experiments as follows:
1. simulation conditions
Creating a target model with 3 points, and performing a simulation test on a computer by using MATLAB R2018b software, wherein SAR system simulation parameters are shown in tables 1, 2 and 3:
TABLE 1 SAR System simulation parameters 1
Figure BDA0002752677460000061
TABLE 2 SAR System simulation parameters 2
Figure BDA0002752677460000062
TABLE 3 SAR System simulation parameters 3
Figure BDA0002752677460000063
2. Emulated content
Simulation 1, simulating the azimuth spectrum of the echo by using the radar pulse coding theory and the applied method in the background art under the SAR system simulation parameters of table 1, and the result is shown in fig. 5.
Simulation 2, under the SAR system simulation parameters of table 1, the method of the present invention is used to simulate the azimuth spectrum of the echo, and the result is shown in fig. 6.
Simulation 3, under the SAR system simulation parameters of table 2, performing conventional single pulse imaging on the target, wherein the pulse repetition frequency is the equivalent pulse repetition frequency of the present invention that employs the parameters of table 3 for imaging, and the imaging result is shown in fig. 7.
Simulation 4, in the SAR system simulation parameters in table 3, the target is imaged by using the method of the present invention, and the imaging result is shown in fig. 8.
3. Analysis of simulation results
Comparing fig. 5 and fig. 6, it can be seen that when the method of the radar pulse coding theory and application in the background art is applied to a high-speed platform, the azimuth spectrum of the echo is aliased and cannot be used for SAR imaging, whereas when the method of the present invention is applied to a high-speed platform, the azimuth spectrum of the echo is not aliased and can be used for SAR imaging.
Comparing the imaging result graphs of fig. 7 and fig. 8, it can be seen that the image noise in fig. 8 is significantly reduced, and the imaging quality is significantly better than that in fig. 7, which shows that the present invention not only effectively improves the signal-to-noise ratio of the SAR image, but also solves the imaging problem of the high-speed SAR platform.

Claims (5)

1.一种基于连续脉冲编码提升高速SAR平台信噪比的成像方法，其特征在于，包括如下：1. an imaging method based on continuous pulse coding to improve the signal-to-noise ratio of high-speed SAR platform, is characterized in that, comprises as follows: (1)设计脉冲串信号，并重复发射该脉冲串信号，其中，重复周期为脉冲串信号的宽度，每个脉冲串信号包含多个单脉冲信号，单脉冲信号间的空隙为接收窗口；(1) Design a pulse train signal, and transmit the pulse train signal repeatedly, wherein, the repetition period is the width of the pulse train signal, each pulse train signal contains a plurality of single pulse signals, and the gap between the single pulse signals is the receiving window; (2)根据发射的脉冲串信号，模拟SAR回波信号，得到原始的混叠回波信号；(2) According to the transmitted pulse train signal, simulate the SAR echo signal to obtain the original aliased echo signal; (3)根据发射的脉冲串信号的形式构建多元线性方程组：LX＝R，其中L是各个接收窗口的观测矩阵，X是需要被解算出来的所有完整回波的集合，R是各个接收窗口的混叠回波信号；(3) Construct a multivariate linear equation system according to the form of the transmitted pulse train signal: LX=R, where L is the observation matrix of each receiving window, X is the set of all complete echoes that need to be solved, and R is each receiving window. The aliased echo signal of the window; (4)从步骤(3)建立的多元线性方程组中按照确定的步长选取多个方程数量相同的子方程组，进行所有完整回波的集合X的求解，得到解混叠后的回波信号；(4) From the multivariate linear equation system established in step (3), select a plurality of sub-equations with the same number of equations according to the determined step size, and solve the set X of all complete echoes to obtain the de-aliased echoes Signal; (5)对解混叠后的回波信号进行均匀分组并同组叠加，将叠加后的回波信号按照等效的脉冲重复频率PRF进行SAR成像。(5) The de-aliased echo signals are uniformly grouped and superimposed in the same group, and the superimposed echo signals are subjected to SAR imaging according to the equivalent pulse repetition frequency PRF. 2.根据权利要求1所述的方法，其特征在于，(1)中设计的脉冲串信号，是由S、0、-S组成的脉冲串，其中S是时宽为TP的常规雷达发射的线性调频信号，该线性调频信号的间隔固定为TP或者2TP，即一个或者两个接收窗口；-S是给S附加一个π的相位，0代表一个时宽为TP的接收窗口；雷达以脉冲串的时宽为周期重复发射脉冲串信号。2. The method according to claim 1, wherein the pulse train signal designed in (1) is a pulse train composed of S, 0, -S, wherein S is a conventional radar emission with a time width of TP The chirp signal, the interval of the chirp signal is fixed as TP or 2TP , that is, one or two receive windows; -S is to add a phase of π to S, and 0 represents a receive window with a time width of TP ; The radar repeatedly transmits the pulse train signal with the time width of the pulse train as the period. 3.根据权利要求1所述方法，其特征在于，(3)中根据发射的脉冲串信号形式构建多元线性方程组，实现如下：3. method according to claim 1 is characterized in that, in (3), construct multivariate linear equation system according to the pulse train signal form of transmission, realize as follows: 3a)设X是需要被解算出来的所有完整回波的集合，单个脉冲对应的场景回波从开始接收到接收完毕的持续时间为T,定义N为T/TP的向上取整数值，其中TP为线性调频信号的时宽，将X以TP为单位，划分为N段，记为X＝[X1,X2...Xn...XN]T，其中Xn为第n段回波，n∈[1,N]；3a) Let X be the set of all complete echoes that need to be solved, the duration of the scene echo corresponding to a single pulse from the beginning to the completion of reception is T, and N is defined as the upward integer value of T/T P , where TP is the time width of the chirp signal, and X is divided into N segments with TP as the unit, denoted as X=[X 1 , X 2 ... X n ... X N ] T , where X n is the n-th echo, n∈[1,N]; 3b)将各个接收窗口的混叠回波信号记为R＝[R1,R2...Rm...RM]T，Rm为第m个接收窗口的混叠回波信号，m∈[1,M]，M为接收窗口的总个数；3b) Denote the aliased echo signal of each receiving window as R=[R 1 , R 2 . . . R m ... R M ] T , where R m is the aliased echo signal of the mth receiving window, m∈[1,M], M is the total number of receiving windows; 3c)根据回波长度与发射的脉冲串信号形式得到的观测矩阵L：3c) The observation matrix L obtained according to the echo length and the transmitted burst signal form:
Figure FDA0002752677450000021
Figure FDA0002752677450000021
 L中的元素lmn代表第m个接收窗口是否存在第n段回波Xn，m∈[1,M]，n∈[1,N]，若存在，则根据Xn对应的发射单脉冲的正负,分别取1或者-1，若第m个接收窗口不存在回波Xn，则取值为0，The element l mn in L represents whether there is the n-th echo X n in the m-th receiving window, m∈[1,M], n∈[1,N], if so, the single pulse is transmitted according to the corresponding Xn The positive and negative of , take 1 or -1 respectively, if there is no echo X n in the mth receiving window, the value is 0, 在不考虑噪声的情况下，可构建线性方程组LX＝R，记为方程组Y，以进行完整回波集合X的求解，考虑噪声时，真实的接收窗信号模型应为：LX+N＝R，在进行回波解算的同时，也可以获得噪声的变化情况，以此来衡量雷达信噪比的改善。Without considering noise, linear equations LX=R can be constructed, denoted as equation Y, to solve the complete echo set X. When noise is considered, the real receiving window signal model should be: LX+N= R, while the echo solution is performed, the change of the noise can also be obtained to measure the improvement of the radar signal-to-noise ratio. 4.根据权利要求1所述的方法，其特征在于，(4)中选取多个方程数量相同的子方程组，得到解混叠后的回波信号，实现如下：4. method according to claim 1, is characterized in that, in (4), choose the same sub-equation system of multiple equation quantity, obtain the echo signal after solution aliasing, realize as follows: 4a)在线性方程组Y中选择Q个连续的方程，构成属于Y的子线性方程组lx＝r，记为y，对x进行求解可得：x＝(lTl)-1lTr，其中Q＞＝N，l是对L按行抽取的的子矩阵，l的秩大于等于N，即lTl是可逆矩阵，x是某个完整回波，x∈X，，r是R的子向量；4a) Select Q continuous equations in the linear equation set Y to form a sub-linear equation set lx=r belonging to Y, denoted as y, and solve x to get: x=(l T l) -1 l T r , where Q>=N, l is a sub-matrix extracted from L by row, the rank of l is greater than or equal to N, that is, l T l is an invertible matrix, x is a complete echo, x∈X, r is R subvector of ; 4b)选取K为步长，以方程组y为参考，在Y中依次选取Q个连续的方程组成其它子线性方程组，直至Y中所有方程都被选取，求解每个方程组对应的x，进而获得解混叠后的完整回波集合X。4b) Select K as the step size, take the equation set y as a reference, select Q consecutive equations in Y to form other sub-linear equation sets, until all equations in Y are selected, and solve the x corresponding to each equation set, Then the complete echo set X after de-aliasing is obtained. 5.根据权利要求1所述的方法，其特征在于，(5)的等效的脉冲重复频率PRF，由将回波分组后组内回波数num与接收窗口分布周期T1的乘积取倒数得到。5. The method according to claim 1, wherein the equivalent pulse repetition frequency PRF of (5) is obtained by taking the reciprocal of the product of the echo number num in the group and the receiving window distribution period T 1 after the echoes are grouped .
CN202011190783.6A 2020-10-30 2020-10-30 Imaging method for improving signal-to-noise ratio of high-speed SAR platform based on continuous pulse coding Active CN112346058B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011190783.6A CN112346058B (en) 2020-10-30 2020-10-30 Imaging method for improving signal-to-noise ratio of high-speed SAR platform based on continuous pulse coding

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011190783.6A CN112346058B (en) 2020-10-30 2020-10-30 Imaging method for improving signal-to-noise ratio of high-speed SAR platform based on continuous pulse coding

Publications (2)

Publication Number Publication Date
CN112346058A true CN112346058A (en) 2021-02-09
CN112346058B CN112346058B (en) 2023-02-07

Family

ID=74357027

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011190783.6A Active CN112346058B (en) 2020-10-30 2020-10-30 Imaging method for improving signal-to-noise ratio of high-speed SAR platform based on continuous pulse coding

Country Status (1)

Country Link
CN (1) CN112346058B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113111758A (en) * 2021-04-06 2021-07-13 中山大学 SAR image ship target identification method based on pulse neural network
CN114428229A (en) * 2022-01-02 2022-05-03 西安电子科技大学 Signal-to-noise ratio improving method for pulse coding radar with any time interval
CN114488151A (en) * 2022-04-08 2022-05-13 中国科学院空天信息创新研究院 Active and passive combined detection method, device, equipment and medium for observation ships

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3339895A1 (en) * 2016-12-22 2018-06-27 Airbus Defence and Space GmbH Multiple input multiple output, mimo, radar system
CN109782284A (en) * 2019-03-15 2019-05-21 中国科学院电子学研究所 A method for realizing long-baseline synchronous interferometric SAR based on pulse coding
CN109946654A (en) * 2019-01-30 2019-06-28 西安电子科技大学 Radar Element-Pulse Coding and Processing Method
CN110261851A (en) * 2019-03-15 2019-09-20 中国科学院电子学研究所 A method of full-polarization SAR is realized based on pulse code
CN110412570A (en) * 2018-10-19 2019-11-05 西安电子科技大学 HRWS-SAR Imaging Method Based on Spatial Pulse Phase Coding

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3339895A1 (en) * 2016-12-22 2018-06-27 Airbus Defence and Space GmbH Multiple input multiple output, mimo, radar system
CN110412570A (en) * 2018-10-19 2019-11-05 西安电子科技大学 HRWS-SAR Imaging Method Based on Spatial Pulse Phase Coding
CN109946654A (en) * 2019-01-30 2019-06-28 西安电子科技大学 Radar Element-Pulse Coding and Processing Method
CN109782284A (en) * 2019-03-15 2019-05-21 中国科学院电子学研究所 A method for realizing long-baseline synchronous interferometric SAR based on pulse coding
CN110261851A (en) * 2019-03-15 2019-09-20 中国科学院电子学研究所 A method of full-polarization SAR is realized based on pulse code

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
LUPENG GUO等: "Inter-pulse Phase Coding For MIMO-SAR Imaging", 《2019 6TH ASIA-PACIFIC CONFERENCE ON SYNTHETIC APERTURE RADAR (APSAR)》 *
YAPENG HE等: "Frequency-Coded Pulse Radar Imaging via Compressive Sensing", 《IEEE》 *
王岩飞等: "雷达编码脉冲理论方法及应用", 《雷达学报》 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113111758A (en) * 2021-04-06 2021-07-13 中山大学 SAR image ship target identification method based on pulse neural network
CN113111758B (en) * 2021-04-06 2024-01-12 中山大学 SAR image ship target recognition method based on impulse neural network
CN114428229A (en) * 2022-01-02 2022-05-03 西安电子科技大学 Signal-to-noise ratio improving method for pulse coding radar with any time interval
CN114488151A (en) * 2022-04-08 2022-05-13 中国科学院空天信息创新研究院 Active and passive combined detection method, device, equipment and medium for observation ships
CN114488151B (en) * 2022-04-08 2022-06-24 中国科学院空天信息创新研究院 Active and passive combined detection method, device, equipment and medium for observation ship

Also Published As

Publication number Publication date
CN112346058B (en) 2023-02-07

Similar Documents

Publication Publication Date Title
CN112346058A (en) Imaging method for improving signal-to-noise ratio of high-speed SAR platform based on continuous pulse coding
CN107678028B (en) Microwave staring correlated imaging method under low signal-to-noise ratio condition
Aberman et al. Sub-Nyquist SAR via Fourier domain range-Doppler processing
CN101526614B (en) SAR echo rapid simulation method based on sub-aperture and equivalent scatterer
CN111505639B (en) A Wide Sparse Imaging Method for Synthetic Aperture Radar Based on Variable Repetition Sampling Mode
CN106199602B (en) A kind of Staggered-SAR echo-signals method for reconstructing
CN102313884A (en) Target track-before-detect (TBD) method based on multi-frame coherent integration
CN112835009A (en) A Dataset Expansion Method Based on FMCW Radar RAI
CN107942327A (en) Single channel HRWS SAR imaging methods based on impulse phase coding
CN108008389A (en) A kind of fast frequency-domain rear orientation projection three-D imaging method based on GPU
CN105093225A (en) Inverse synthetic aperture radar self-focusing imaging method based on double sparse constraints
CN115407335A (en) MIMO-SAR defuzzification method and device based on OFDM-chirp signal and DBF processing
CN107015223A (en) A kind of synthetic aperture radar orientation signal reconstruction method and apparatus
CN105717508A (en) Foresight imaging method of airborne radar based on azimuth modulation of emitted waveform
CN105738897A (en) Signal distance image reconstruction method based on combined sparse characteristics
CN113484862A (en) Self-adaptive high-resolution wide-range SAR clear reconstruction imaging method
CN103105610A (en) DPC-MAB SAR imaging method based on non-uniform sampling
CN108646247A (en) Inverse synthetic aperture radar imaging method based on Gamma process linear regression
CN102298141A (en) Airborne pulse doppler radar iterative solution range ambiguity method
CN103576151B (en) Azimuth multi-channel SAR imaging method and system based on compressed sensing
CN111624600B (en) A SAR moving target detection method and system based on one-bit quantization
CN109669184A (en) A kind of synthetic aperture radar azimuth ambiguity removing method based on full convolutional network
CN107102328B (en) FPGA-based real-time imaging signal processing method and FPGA
CN110133656B (en) Three-dimensional SAR sparse imaging method based on decomposition and fusion of co-prime array
CN112285709A (en) Atmospheric ozone remote sensing laser radar data fusion method based on deep learning

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