CN109471100A - A kind of SAR doppler frequency rate estimation method and system - Google Patents
A kind of SAR doppler frequency rate estimation method and system Download PDFInfo
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- CN109471100A CN109471100A CN201811202837.9A CN201811202837A CN109471100A CN 109471100 A CN109471100 A CN 109471100A CN 201811202837 A CN201811202837 A CN 201811202837A CN 109471100 A CN109471100 A CN 109471100A
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- 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 present invention provides a kind of SAR doppler frequency rate estimation method and system, method includes: to carry out distance to the descending preceding M distance unit of selections arrangement of energy after compression according to distance unit to echo data；The initial tune frequency values of calculating distance unit and initial stepping length；3 nodes are set and carry out breadth search, are successively denoted as node 1, node 2, node 3, carry out Azimuth Compression processing, and calculate contrast value；If the contrast of node 2 is maximum, breadth search terminates；Deep search is carried out according to 3 joint structures, 5 nodes, carries out Azimuth Compression processing, and calculate contrast value；Judge whether doppler frequency rate restrains；If then terminating deep search, accurate doppler frequency rate deviation is obtained；Otherwise 5 nodes are reconfigured and calculate each node contrast, until doppler frequency rate is restrained.The present invention achievees the purpose that fast convergence by Optimizing Search strategy.
Description
Technical field
The present invention relates to synthetic aperture radar image-forming technical field, espespecially a kind of SAR doppler frequency rate estimation method and
System.
Background technique
Synthetic aperture radar (abbreviation SAR) is to form synthetic aperture using the time integral of the direction of motion to complete orientation
High-resolution imaging, the quadratic phase item (being made of doppler frequency rate) of echo-signal orientation directly affect imaging and focusing essence
Degree, therefore show that accurate doppler frequency rate parameter is the key that realize that SAR orientation focuses.Doppler frequency rate information is
It is generated by SAR platform movement, therefore doppler frequency rate can be obtained by the moving parameter information of SAR platform, but due to
The Desired Track often needed with imaging and focusing in SAR platform motion process will lead to there is movement warp and directly pass through fortune
There are deviations for the doppler frequency rate and actual value that dynamic parameter obtains, and then image focusing effect is caused to be deteriorated.The fortune of SAR platform
Dynamic feature can be shown in the SAR echo data of acquisition, can be obtained by carrying out doppler frequency rate estimation using echo data
It, accordingly can accurately compensating for doppler tune exemplary frequency deviation values to accurate doppler frequency rate information.
Summary of the invention
The object of the present invention is to provide a kind of SAR doppler frequency rate estimation method and system, realization passes through Optimizing Search
Strategy achievees the purpose that fast convergence.
Technical solution provided by the invention is as follows:
The present invention provides a kind of SAR doppler frequency rate estimation method characterized by comprising carries out to echo data
To compression, energy after compression according to distance unit is descending to be arranged successively distance, chooses M distance list before arrangement
Member remembers that the array of the M distance unit composition is xrc；Calculate xrcIn each distance unit initial tune frequency values ka0,
It requires to choose initial stepping length Δ k no more than the focusing accuracy of π/4 according to the maximum phase error of SAR imaging tolerance；Setting 3
The node {-Δ k, 0, Δ k } of a doppler frequency rate deviation carries out breadth search, 3 nodes be successively denoted as node 1, node 2,
Node 3, using 3 nodes to xrcAzimuth Compression processing is carried out, and calculates the contrast value of 3 nodes；When pair of the node 2
When than degree maximum, breadth search terminates, and 3 nodes {-Δ k, 0, Δ k } are denoted as { Δ k10,Δk20,Δk30, it carries out depth and searches
Rope；According to { Δ k10,Δk20,Δk305 node { Δ k of construction1,Δk2,Δk3,Δk4,Δk5, utilize the how general of 5 nodes
It strangles and adjusts frequency departure to xrcAzimuth Compression processing is carried out, and calculates the contrast value of 5 nodes, wherein
If doppler frequency rate deviation Δ kiThe contrast of corresponding node is maximum, then according to Δ kiJudge Doppler's tune
Whether frequency restrains, the Δ kiFor { the Δ k1,Δk2,Δk3,Δk4,Δk5In any one；Terminate if convergence
Deep search obtains accurate doppler frequency rate deviation Δ ka；Otherwise 5 node { Δ k are reconfigured1',Δk2',Δ
k3',Δk4',Δk5' each node contrast is calculated, until doppler frequency rate is restrained；Wherein
Further, to echo data progress distance to compression, the energy of n-th of distance unit after compression are as follows:
Wherein, N indicates total orientation points, and x (n, i) indicates i-th echo amplitude value of n-th of distance unit, n
For positive integer.
Further, xrcIn m-th of distance unit frequency modulation rate initial value ka0Are as follows:
Wherein, v is SAR platform movement velocity, and λ is signal wavelength, RmOblique distance for m-th of distance unit away from SAR platform,
θsqFor imaging center moment angle of squint, 1≤m≤M, and m are positive integer；Wherein,Wherein, RsFor center oblique distance, NrFor distance unit number, C is the light velocity, fsTo adopt
Sample frequency；Focusing accuracy requirement of the maximum phase error of SAR imaging tolerance no more than π/4, tolerable doppler frequency rate
Deviation Δ kerrAre as follows:Wherein, TaFor imaging cycle；Take Δ kerrMaximum value be tolerable Doppler
Frequency modulation rate maximum deflection difference value Δ kthr, that is, haveInitial stepping length Δ k=(3~5) Δ kthr。
Further, to xrcIt carries out Azimuth Compression processing to specifically include: the Doppler of m-th of distance unit in each node
Frequency modulation rate kmFor doppler frequency rate initial value ka0(m) with corresponding node in doppler frequency rate deviation delta knThe sum of, Δ knFor
{-Δ k, 0, Δ k } or { Δ k1,Δk2,Δk3,Δk4,Δk5Or { Δ k1',Δk2',Δk3',Δk4',Δk5' in it is any
One；Doppler frequency rate kmDistance unit Azimuth Compression reference function are as follows:
Wherein, taFor the orientation time, j indicates plural number, and exp is the power function using natural constant the bottom of as；The treatment process of Azimuth Compression
Are as follows: I (m, km)=abs (FFT (xrc(m)*sref(km))) wherein, xrcIt (m) is echo data xrcM-th distance unit adopt
Sample sequence, FFT are Fourier transformation, and abs expression takes absolute value, I (m, km) it is that m-th of distance unit uses doppler frequency rate
kmFinish the Azimuth Compression image intensity that treated.
Further, to xrcDegree of comparing calculating specifically includes:
Wherein, C (m, km) it is to be calculated after m-th of distance unit carries out Azimuth Compression using doppler frequency rate km
Contrast value, E expression take mean value；The contrast value that all distance unit that each node Azimuth Compression obtains calculate is asked equal respectively
Value, contrast of the mean value as the node, i.e. doppler frequency rate deviation are Δ knThe contrast of corresponding node are as follows:
Further, SAR doppler frequency rate estimation method further include: when the contrast maximum of the node 1, to negative
Direction search, reconfiguring three nodes using Δ k'=- Δ k as step value, { 0, Δ k', 2 Δ k'} are denoted as new node 1, new to save
Point 2, new node 3, carries out Azimuth Compression and contrast calculates；Terminate breadth search if the contrast maximum of the new node 2,
By { 0, Δ k', 2 Δ k'} are denoted as { Δ k10,Δk20,Δk30Carry out deep search；If the contrast maximum of the new node 3
It is that step value reconfigures three nodes { 0, Δ k ", 2 Δ k " } progress Azimuth Compression and contrast meter again by the Δ of Δ k "=2 k'
It calculates, until the contrast maximum of node 2 terminates breadth search, carries out deep search.
Further, SAR doppler frequency rate estimation method further include: when the contrast maximum of the node 3, Xiang Zheng
Direction search, reconfiguring three nodes using Δ k'=Δ k as step value, { 0, Δ k', 2 Δ k'} are denoted as new node 1, new node
2, new node 3, carries out Azimuth Compression and contrast calculates；Terminate breadth search if the contrast maximum of the new node 2, it will
{ 0, Δ k', 2 Δ k'} are denoted as { Δ k10,Δk20,Δk30Carry out deep search；It will if the contrast maximum of the new node 3
The Δ of Δ k "=2 k' is that step value reconfigures three nodes { 0, Δ k ", 2 Δ k " } progress Azimuth Compression and contrast meter again
It calculates, until the contrast maximum of node 2 terminates breadth search, carries out deep search.
Further, the convergent condition of doppler frequency rate value are as follows: | Δ ki+1-Δki-1|≤Δkthr, the wherein value of i
It is 2,3 or 4, Δ kiFor the corresponding doppler frequency rate deviation of the maximum node of contrast；When doppler frequency rate convergence,
Accurate doppler frequency rate deviation Δ kaAre as follows: Δ ka=(Δ ki+1+Δki-1)/2。
Further, SAR doppler frequency rate estimation method further include: after the completion of deep search, m-th distance unit
Doppler frequency rate estimated value are as follows: ka(m)=ka0(m)+Δka。
The present invention also provides distances to compression module, carries out distance to compression to echo data, after compression according to away from
It is descending from the energy of unit to be arranged successively, M distance unit before arranging is chosen, remembers the number of the M distance unit composition
Group is xrc；Computing module calculates xrcIn each distance unit initial tune frequency values ka0, most according to SAR imaging tolerance
Big phase error requires to choose initial stepping length Δ k no more than the focusing accuracy of π/4；3 Doppler's tune are arranged in analysis module
The node {-Δ k, 0, Δ k } of frequency departure carries out breadth search, and 3 nodes are successively denoted as node 1, node 2, node 3, utilize 3
A node is to XrcAzimuth Compression processing is carried out, and calculates the contrast value of 3 nodes；The analysis module, if the node 2
Contrast is maximum, then breadth search terminates, and three nodes {-Δ k, 0, Δ k } are denoted as { Δ k10,Δk20,Δk30, it carries out deep
Degree search；According to { Δ k10,Δk20,Δk305 node { Δ k of construction1,Δk2,Δk3,Δk4,Δk5, utilize 5 nodes
Doppler frequency rate deviation is to xrcAzimuth Compression processing is carried out, and calculates the contrast value of 5 nodes, wherein
Control module, if doppler frequency rate deviation Δ kiThe contrast of corresponding node is maximum, then judges Doppler
Whether frequency modulation rate restrains, the Δ kiFor { the Δ k1,Δk2,Δk3,Δk4,Δk5In any one；If then terminating
Deep search obtains accurate doppler frequency rate deviation Δ ka；Otherwise 5 node { Δ k are reconfigured1',Δk2',Δ
k3',Δk4',Δk5' each node contrast is calculated, until doppler frequency rate is restrained；Wherein
A kind of SAR doppler frequency rate estimation method and system provided through the invention, can bring following at least one
Kind the utility model has the advantages that
1, in the present invention, it is up to criterion to focus good SAR image contrast, applicable scene is wide, is widely used.
2, in the present invention, the number of iterations is reduced by controlling the stepping length searched for each time and step-by-step system, is reached
Optimum search effect.
Detailed description of the invention
Below by clearly understandable mode, preferred embodiment is described with reference to the drawings, to a kind of SAR doppler frequency rate
Above-mentioned characteristic, technical characteristic, advantage and its implementation of estimation method and system are further described.
Fig. 1 is a kind of flow chart of one embodiment of SAR doppler frequency rate estimation method of the present invention；
Fig. 2 is a kind of flow chart of 4th embodiment of SAR doppler frequency rate estimation method of the present invention；
Fig. 3 is a kind of structural schematic diagram of 5th embodiment of SAR doppler frequency rate estimating system of the present invention；
Fig. 4 is each distance unit of an example of a kind of SAR doppler frequency rate estimation method of the present invention and system
Initial frequency modulation rate；
Fig. 5 is each distance row of one embodiment of a kind of SAR doppler frequency rate estimation method of the present invention and system
Doppler frequency rate estimated value.
Specific embodiment
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, Detailed description of the invention will be compareed below
A specific embodiment of the invention.It should be evident that drawings in the following description are only some embodiments of the invention, for
For those of ordinary skill in the art, without creative efforts, it can also be obtained according to these attached drawings other
Attached drawing, and obtain other embodiments.
To make simplified form, part related to the present invention is only schematically shown in each figure, they are not represented
Its practical structures as product.In addition, there is identical structure or function in some figures so that simplified form is easy to understand
Component only symbolically depicts one of those, or has only marked one of those.Herein, "one" is not only indicated
" only this ", can also indicate the situation of " more than one ".
The first embodiment of the present invention, as shown in Figure 1, a kind of SAR doppler frequency rate estimation method, comprising:
Distance is carried out to compression to echo data, energy after compression according to distance unit is descending successively to be arranged
Column choose M distance unit before arranging, and the array of note M distance unit composition is xrc；
Calculate xrcIn each distance unit initial tune frequency values ka0, missed according to the maximum phase of SAR imaging tolerance
Difference requires to choose initial stepping length Δ k no more than the focusing accuracy of π/4；
The node {-Δ k, 0, Δ k } that 3 doppler frequency rate deviations are arranged carries out breadth search, and 3 nodes are successively denoted as
Node 1, node 2, node 3, using 3 nodes to xrcAzimuth Compression processing is carried out, and calculates the contrast value of 3 nodes；
When the contrast maximum of node 2, breadth search terminates, and 3 nodes {-Δ k, 0, Δ k } are denoted as { Δ k10,Δ
k20,Δk30, carry out deep search；
According to { Δ k10,Δk20,Δk305 node { Δ k of construction1,Δk2,Δk3,Δk4,Δk5, utilize 5 nodes
Doppler frequency rate deviation to xrcAzimuth Compression processing is carried out, and calculates the contrast value of 5 nodes, wherein
If doppler frequency rate deviation Δ kiThe contrast of corresponding node is maximum, then according to Δ kiJudge Doppler's tune
Whether frequency restrains, Δ kiFor { Δ k1,Δk2,Δk3,Δk4,Δk5In any one；
Terminate deep search if convergence, obtains accurate doppler frequency rate deviation Δ ka；Otherwise 5 are reconfigured
Node { Δ k1',Δk2',Δk3',Δk4',Δk5' each node contrast is calculated, until doppler frequency rate is restrained；Wherein
Specifically, in digital signal processing, the echo data of SAR is stored in two-dimensional matrix in the present embodiment,
Distance is to arrange storage to data, and Data in Azimuth Direction is with row storage.Each column in matrix are different direction instance samples
For distance to echo data, a line in matrix is a distance unit and a Data in Azimuth Direction.For example, for the square of M*N
Battle array has M row N column, and distance is just M to points, and orientation points are N, there is M distance unit.
Distance is carried out to compression to the echo data of SAR, after compression by the energy of all distance unit by greatly to
It is small to be arranged successively, M before arranging distance unit are chosen, the array of note M distance unit composition is xrc, according in SAR platform
The velocity information of inertial measuring unit calculates xrcIn each distance unit initial tune frequency values ka0, it is imaged and is held according to SAR
The maximum phase error born requires to choose initial stepping length Δ k no more than the focusing accuracy of π/4.3 Doppler FMs are set
The node {-Δ k, 0, Δ k } of rate deviation carries out breadth search, and 3 nodes are successively denoted as node 1, node 2, node 3, utilize 3
Node is to XrcAzimuth Compression processing is carried out, and calculates the contrast value of 3 nodes；When the contrast maximum of node 2, range is searched
3 nodes {-Δ k, 0, Δ k } are denoted as { Δ k by hitch beam10,Δk20,Δk30, i.e. ,-Δ k=Δ k10, 0=Δ k20, Δ k=
Δk30, then carry out deep search.According to { Δ k10,Δk20,Δk305 node { Δ k of construction1,Δk2,Δk3,Δk4,Δ
k5, using the doppler frequency rate deviation of 5 nodes to xrcAzimuth Compression processing is carried out, and calculates the contrast of 5 nodes
Value, wherein
If doppler frequency rate deviation Δ kiThe contrast of corresponding node is maximum, then whether judges doppler frequency rate
Convergence, Δ kiFor { Δ k1,Δk2,Δk3,Δk4,Δk5In any one.Terminate deep search if convergence, obtains accurate
Doppler frequency rate deviation Δ ka；Otherwise according to Δ ki{ Δ k1,Δk2,Δk3,Δk4,Δk5Reconfigure 5 sections
Point { Δ k1',Δk2',Δk3',Δk4',Δk5' each node contrast is calculated, until doppler frequency rate is restrained, wherein
The present invention proposes a kind of SAR doppler frequency rate estimation method based on contrast optimization self-focusing, passes through
Stepping length in reasonable command deployment, chooses the initial stepping length and convergence criterion for meeting imaging demand, reduces operand,
The fast convergence for reaching doppler frequency rate, effectively reduces search time, very well satisfies SAR imaging to Doppler FM
The requirement of rate estimated accuracy and real-time.
Second embodiment of the invention, is the optimal enforcement example of above-mentioned first embodiment, and the present embodiment and above-mentioned first are implemented
Example is compared, and main improve is,
To echo data progress distance to compression, the energy of n-th of distance unit after compression are as follows:
Wherein, N indicates that total orientation is counted, i-th echo amplitude value of x (n, i) n-th of distance unit of expression, 1
≤ n≤M, and n is positive integer；
xrcIn m-th of distance unit frequency modulation rate initial value ka0Are as follows:
Wherein, v is SAR platform movement velocity, and λ is signal wavelength, RmOblique distance for m-th of distance unit away from SAR platform,
θsqFor imaging center moment angle of squint, 1≤m≤M, and m are positive integer；Wherein,
Wherein, RsFor center oblique distance, NrFor distance unit number, C is the light velocity, fsFor sample frequency；
Focusing accuracy requirement of the maximum phase error of SAR imaging tolerance no more than π/4, tolerable doppler frequency rate
Deviation Δ kerrAre as follows:
Wherein, TaFor imaging cycle；
Take Δ kerrMaximum value be tolerable doppler frequency rate maximum deflection difference value Δ kthr, that is, have
Initial stepping length Δ k=(3~5) Δ kthr；
The convergent condition of doppler frequency rate value are as follows: | Δ ki+1-Δki-1|≤Δkthr, wherein the value of i is 2,3 or 4,
ΔkiFor the corresponding doppler frequency rate deviation of the maximum node of contrast；
When doppler frequency rate convergence, accurate doppler frequency rate deviation Δ kaAre as follows:
Δka=(Δ ki+1+Δki-1)/2；
SAR doppler frequency rate estimation method further include:
After the completion of deep search, the doppler frequency rate estimated value of m-th of distance unit are as follows:
ka(m)=ka0(m)+Δka。
Specifically, in the present embodiment, distance is carried out to compression to echo data, n-th distance unit after compression
Energy are as follows:Wherein, N indicates total orientation points, and x (n, i) indicates n-th of distance unit
I-th echo amplitude value, n is positive integer.By P1, P2, P3... PnIt is descending to be arranged successively, M are chosen before arranging
Distance unit, the array of note M distance unit composition is xrc, according to the velocity information meter of inertial measuring unit in SAR platform
Calculate xrcIn each distance unit initial tune frequency values ka0,Wherein, v
For SAR platform movement velocity, λ is signal wavelength, RmOblique distance for m-th of distance unit away from SAR platform, as SAR platform phase
Linear distance between position center and target point, θsqFor imaging center moment angle of squint, as velocity vector and line of sight is pressed from both sides
The complementary angle at angle takes imaging center moment, 1≤m≤M, and m is positive because there is slight difference in different imaging moments angle of squint here
Integer.Wherein,Wherein, RsFor center oblique distance, i.e., the imaging center moment is oblique
Away from NrFor distance unit number, i.e., the distance unit number of entire matrix script, such as M ceiling capacity of selection in X*Y matrix
Distance unit, then Nr=X, C are the light velocity, fsFor sample frequency, to the frequency that echo is sampled, the data of echo samples are with square
Battle array mode stores.Require the initial stepping of selection long no more than the focusing accuracy of π/4 according to the maximum phase error of SAR imaging tolerance
Spend Δ k.Wherein, the focusing accuracy requirement according to the maximum phase error of SAR imaging tolerance no more than π/4, it is tolerable how general
It strangles and adjusts exemplary frequency deviation values Δ kerrFor,TaFor imaging cycle, i.e., constituted as unit of the synthetic aperture time
Time cycle.Take Δ kerrMaximum value be tolerable doppler frequency rate maximum deflection difference value Δ kthr,Just
Beginning stepping length Δ k=(3~5) Δ kthr.Then breadth search and deep search are carried out respectively until doppler frequency rate is restrained
Obtain accurate doppler frequency rate deviation Δ ka.If initial stepping length is shorter, may result in breadth search when
Between it is elongated；If initial stepping length is longer, the time that may result in deep search is elongated, comprehensively considers breadth search and depth
The time for spending search, preferentially choosing initial stepping length is 4 times of doppler frequency rate maximum deflection difference value this empirical values, is being adjusted
Certain stability is all had when frequency departure is either large or small.
After carrying out deep search, the contrast value of 5 nodes, Δ k are comparediIt is corresponding more for the maximum node of contrast
Pu Le tune exemplary frequency deviation values, if | Δ ki+1-Δki-1|≤Δkthr, then doppler frequency rate value restrains, accurate Doppler FM
Rate deviation Δ kaAre as follows: Δ ka=(Δ ki+1+Δki-1)/2。
Third embodiment of the invention, is the optimal enforcement example of above-mentioned second embodiment, and the present embodiment and above-mentioned second are implemented
Example is compared, and main improve is,
To xrcAzimuth Compression processing is carried out to specifically include:
The doppler frequency rate k of m-th of distance unit in each nodemFor doppler frequency rate initial value ka0(m) with it is right
Answer the sum of the doppler frequency rate deviation delta kn, Δ k in nodenFor {-Δ k, 0, Δ k } or { Δ k1,Δk2,Δk3,Δk4,Δ
k5Or { Δ k1',Δk2',Δk3',Δk4',Δk5' in any one；
Doppler frequency rate kmDistance unit Azimuth Compression reference function are as follows:
Wherein, taFor the orientation time, j indicates plural number, and exp is the power function using natural constant the bottom of as；
The treatment process of Azimuth Compression are as follows:
I(m,km)=abs (FFT (xrc(m)*sref(km)))
Wherein, xrcIt (m) is echo data xrcM-th of distance unit sample sequence, FFT is Fourier transformation, abs
Expression takes absolute value, I (m, km) it is that m-th of distance unit uses doppler frequency rate kmFinish the Azimuth Compression figure that treated
As intensity；
To xrcDegree of comparing calculating specifically includes:
Wherein, C (m, km) it is that m-th of distance unit uses doppler frequency rate kmIt is calculated after progress Azimuth Compression
Contrast value, E expression take mean value；
The contrast value that all distance unit that each node Azimuth Compression obtains calculate is averaged respectively, mean value is used as should
The contrast of node, i.e. doppler frequency rate deviation are Δ knThe contrast of corresponding node are as follows:
C(Δkn)=Σ C (m, ka0(m)+Δkn)。
Specifically, in the present embodiment, distance is carried out to compression to the echo data of SAR, after compression by it is all away from
It is descending from the energy of unit to be arranged successively, choose M before arranging distance unit, the array of note M distance unit composition
For xrc, x is calculated according to the velocity information of inertial measuring unit in SAR platformrcIn each distance unit initial frequency modulation rate
Value ka0, require to choose initial stepping length Δ k no more than the focusing accuracy of π/4 according to the maximum phase error of SAR imaging tolerance.
Then breadth search and deep search are carried out respectively until doppler frequency rate restrains to obtain accurate doppler frequency rate deviation
It is worth Δ ka。
Wherein, breadth search and deep search require successively to carry out Azimuth Compression and contrast calculates.Breadth search side
Position compression process is as follows: the doppler frequency rate k of m-th of distance unit in each nodemFor doppler frequency rate initial value ka0
(m) with corresponding node in doppler frequency rate deviation delta knThe sum of, i.e. km=ka0(m)+Δkn, Δ knCurrently to calculate
The corresponding doppler frequency rate deviation of node, i.e. some value in {-Δ k, 0, Δ k }.Doppler frequency rate kmAway from
Azimuth Compression reference function from unit are as follows:Wherein, taFor orientation time, j
Indicate plural number, exp is the power function using natural constant the bottom of as.The treatment process of Azimuth Compression are as follows: I (m, km)=abs (FFT (xrc
(m)*sref(km))), wherein xrcIt (m) is echo data xrcM-th of distance unit sample sequence, FFT be Fourier become
It changes, abs expression takes absolute value, I (m, km) it is that m-th of distance unit uses doppler frequency rate kmAfter finishing Azimuth Compression processing
Image intensity.Range contrast calculating process is as follows:1≤m≤M, wherein C (m, km) it is m-th of distance
Unit uses doppler frequency rate kmThe contrast value being calculated after Azimuth Compression is carried out, E expression takes mean value.Due to it is each away from
Sample sequence is corresponded to from unit, therefore each distance unit has multiple images intensity, to each in above-mentioned contrast calculation formula
The image intensity of all sample sequences is averaged in distance unit, to obtain the contrast of each distance unit.Then right
The contrast of all distance unit of same node is averaged, i.e.,To
Obtain the contrast of the node.
When the contrast maximum of node 2, breadth search terminates, and carries out deep search.The 3 of breadth search will be carried out before
A node {-Δ k, 0, Δ k } is denoted as { Δ k10,Δk20,Δk30, according to { Δ k10,Δk20,Δk305 node { Δs of construction
k1,Δk2,Δk3,Δk4,Δk5, using the doppler frequency rate deviation of 5 nodes to xrcAzimuth Compression processing is carried out, and is counted
Calculate the contrast value of 5 nodes, wherein
The treatment process of Azimuth Compression are as follows: I (m, km)=abs (FFT (xrc(m)*sref(km))), wherein xrc(m) it is back
Wave number is according to xrcM-th of distance unit sample sequence, FFT is Fourier transformation, and abs expression takes absolute value, I (m, km) it is the
M distance unit uses doppler frequency rate kmFinish the Azimuth Compression image intensity that treated.Doppler frequency rate kmAway from
Azimuth Compression reference function from unit are as follows:Wherein, taFor orientation time, j table
It gives instructions in reply number, exp is the power function using natural constant the bottom of as.The doppler frequency rate k of m-th of distance unit in each nodemFor
Doppler frequency rate initial value ka0(m) with corresponding node in doppler frequency rate deviation delta knThe sum of, i.e. km=ka0(m)+Δ
kn, Δ knFor the corresponding doppler frequency rate deviation of node currently calculated, i.e. { Δ k1,Δk2,Δk3,Δk4,Δ
k5In some value.Range contrast calculating process is as follows:1≤m≤M, wherein C (m, km) it is m-th of distance
Unit uses doppler frequency rate kmThe contrast value being calculated after Azimuth Compression is carried out, E expression takes mean value.Then to same
The contrast of all distance unit of node is averaged, i.e.,To obtain
The contrast of the node.Therefore, the method that the Azimuth Compression of breadth search and deep search and contrast calculate is identical, and difference exists
It is different in the doppler frequency rate deviation of selected node.
Fourth embodiment of the invention is the optimal enforcement example of above-mentioned first embodiment, as shown in Fig. 2, the present embodiment with it is upper
First embodiment to be stated to compare, main improve is,
SAR doppler frequency rate estimation method further include:
When the contrast maximum of node 1, is searched for negative direction, reconfigure three sections by step value of Δ k'=- Δ k
{ 0, Δ k', 2 Δ k'} are denoted as new node 1 to point, and new node 2, new node 3, carries out Azimuth Compression and contrast calculates；
Terminate breadth search if the contrast maximum of new node 2, by { 0, Δ k', 2 Δ k'} are denoted as { Δ k10,Δk20,
Δk30Carry out deep search；
If the contrast maximum of new node 3 by the Δ of Δ k "=2 k' be step value reconfigure again three nodes 0, Δ
K ", 2 Δ k " } Azimuth Compression and contrast calculating are carried out, until the contrast maximum of node 2 terminates breadth search, carry out depth
Search；
When the contrast maximum of node 3, is searched for positive direction, reconfigure three sections by step value of Δ k'=Δ k
{ 0, Δ k', 2 Δ k'} are denoted as new node 1 to point, and new node 2, new node 3, carries out Azimuth Compression and contrast calculates；
Terminate breadth search if the contrast maximum of new node 2, by { 0, Δ k', 2 Δ k'} are denoted as { Δ k10,Δk20,
Δk30Carry out deep search；
If the contrast maximum of new node 3 by the Δ of Δ k "=2 k' be step value reconfigure again three nodes 0, Δ
K ", 2 Δ k " } Azimuth Compression and contrast calculating are carried out, until the contrast maximum of node 2 terminates breadth search, carry out depth
Search.
Specifically, in the present embodiment, distance is carried out to compression to the echo data of SAR, after compression by it is all away from
It is descending from the energy of unit to be arranged successively, choose M before arranging distance unit, the array of note M distance unit composition
For xrc, x is calculated according to the velocity information of inertial measuring unit in SAR platformrcIn each distance unit initial frequency modulation rate
Value ka0, require to choose initial stepping length Δ k no more than the focusing accuracy of π/4 according to the maximum phase error of SAR imaging tolerance.
Then breadth search and deep search are carried out respectively until doppler frequency rate restrains to obtain accurate doppler frequency rate deviation
It is worth Δ ka。
Wherein, breadth search and deep search require successively to carry out Azimuth Compression and contrast calculates.Breadth search side
Position compression process is as follows: the doppler frequency rate k of m-th of distance unit in each nodemFor doppler frequency rate initial value ka0
(m) with corresponding node in doppler frequency rate deviation delta knThe sum of, i.e. km=ka0(m)+Δkn, Δ knCurrently to calculate
The corresponding doppler frequency rate deviation of node, i.e. some value in {-Δ k, 0, Δ k }.Doppler frequency rate kmAway from
Azimuth Compression reference function from unit are as follows:Wherein, taFor orientation time, j table
It gives instructions in reply number, exp is the power function using natural constant the bottom of as.The treatment process of Azimuth Compression are as follows: I (m, km)=abs (FFT (xrc
(m)*sref(km))), wherein xrcIt (m) is echo data xrcM-th of distance unit sample sequence, FFT be Fourier become
It changes, abs expression takes absolute value, I (m, km) it is that m-th of distance unit uses doppler frequency rate kmAfter finishing Azimuth Compression processing
Image intensity.Range contrast calculating process is as follows:1≤m≤M, wherein C (m, km) it is m-th of distance
Unit uses doppler frequency rate kmThe contrast value being calculated after Azimuth Compression is carried out, E expression takes mean value.Due to it is each away from
Sample sequence is corresponded to from unit, therefore each distance unit has multiple images intensity, to each in above-mentioned contrast calculation formula
The image intensity of all sample sequences is averaged in distance unit, to obtain the contrast of each distance unit.Then right
The contrast of all distance unit of same node is averaged, i.e.,To
Obtain the contrast of the node.
When the contrast maximum of node 1, is searched for negative direction, reconfigure three sections by step value of Δ k'=- Δ k
{ 0, Δ k', 2 Δ k'}, i.e. { 0,-Δ k, -2 Δ k } are denoted as new node 1 to point, new node 2, new node 3, according to the method described above again
Secondary progress Azimuth Compression and contrast calculate.The contrast value of new node 2 is greater than new node 1 known to last calculated result
Contrast value, therefore this time there are two types of calculated results, the contrast of new node 2 is maximum, terminates breadth search；Pair of new node 3
It is then that step value reconfigures three nodes { 0, Δ k ", 2 Δ k " } i.e. { 0, -2 Δs again by the Δ of Δ k "=2 k' than degree maximum
K, -4 Δ k } Azimuth Compression and contrast calculating are carried out, repetition is above-mentioned to when calculating process, until three nodes constructed
In node 2 contrast it is maximum, terminate breadth search.
When the contrast maximum of node 3, is searched for positive direction, reconfigure three sections by step value of Δ k'=Δ k
{ 0, Δ k', 2 Δ k'}, i.e. { 0, Δ k, 2 Δ k } are denoted as new node 1 to point, new node 2, new node 3, according to the method described above again
It carries out Azimuth Compression and contrast calculates.The contrast value of new node 2 is greater than pair of new node 1 known to last calculated result
Than angle value, therefore this time there are two types of calculated results, the contrast of new node 2 is maximum, terminates breadth search；The comparison of new node 3
Degree is maximum, then is that step value reconfigures three nodes { 0, Δ k ", 2 Δ k " } i.e. { 0,2 Δ k, 4 Δs again by the Δ of Δ k "=2 k'
K } Azimuth Compression and contrast calculating are carried out, repeat the above-mentioned section to when calculating process, in three nodes constructed
The contrast of point 2 is maximum, terminates breadth search.
3 nodes that above-mentioned last time carries out breadth search are denoted as { Δ k10,Δk20,Δk30, according to { Δ k10,Δ
k20,Δk305 node { Δ k of construction1,Δk2,Δk3,Δk4,Δk5, utilize the doppler frequency rate deviation pair of 5 nodes
xrcAzimuth Compression processing is carried out, and calculates the contrast value of 5 nodes.Pass through the corresponding Doppler's tune of the maximum node of contrast
Exemplary frequency deviation values Δ kiJudge whether doppler frequency rate restrains, Δ kiFor { Δ k1,Δk2,Δk3,Δk4,Δk5In it is any
One.Terminate deep search if convergence, obtains accurate doppler frequency rate deviation Δ ka。
The fifth embodiment of the present invention, as shown in figure 3, a kind of SAR doppler frequency rate estimating system 100, comprising:
Distance carries out distance to compression, according to the energy of distance unit after compression to compression module 110, to echo data
Measure it is descending be arranged successively, choose M distance unit before arranging, the array that M distance unit of note forms is xrc；
Computing module 120, calculates xrcIn each distance unit initial tune frequency values ka0, it is imaged and is tolerated according to SAR
Maximum phase error require to choose initial stepping length Δ k no more than the focusing accuracy of π/4；
Analysis module 130, be arranged 3 doppler frequency rate deviations node {-Δ k, 0, Δ k } carry out breadth search, 3
Node is successively denoted as node 1, node 2, node 3, using 3 nodes to XrcAzimuth Compression processing is carried out, and calculates 3 nodes
Contrast value；
Analysis module 130, if the contrast of node 2 is maximum, breadth search terminates, by three nodes {-Δ k, 0, Δ k }
It is denoted as { Δ k10,Δk20,Δk30, carry out deep search；According to { Δ k10,Δk20,Δk305 node { Δ k of construction1,Δk2,
Δk3,Δk4,Δk5, using the doppler frequency rate deviation of 5 nodes to xrcAzimuth Compression processing is carried out, and calculates 5 sections
The contrast value of point, wherein
Control module 140, if doppler frequency rate deviation Δ kiThe contrast of corresponding node is maximum, then how general judges
Strangle whether frequency modulation rate restrains, Δ kiFor { Δ k1,Δk2,Δk3,Δk4,Δk5In any one；If then terminating depth to search
Rope obtains accurate doppler frequency rate deviation Δ ka；Otherwise 5 node { Δ k are reconfigured1',Δk2',Δk3',Δ
k4',Δk5' each node contrast is calculated, until doppler frequency rate is restrained；Wherein
The concrete operations mode of modules in the present embodiment has been carried out in above-mentioned corresponding embodiment of the method
Detailed description, therefore no longer repeated one by one.
One example of a kind of SAR doppler frequency rate estimation method of the present invention and system, to the echo data of an actual measurement
Adjust the actual result of Frequency Estimation:
The system parameter that calculating process uses is as shown in table 1:
1 system parameter of table
| Parameter name | Parameter value | Parameter name | Parameter value |
| Wavelength X | 0.02m | Distance unit number Nr | 4096 |
| Velocity measurement v | 100m/s | Angle of squint θsq | 20° |
| Sample frequency fs | 200MHz | Imaging cycle Ta | 1s |
| Center oblique distance Rs | 2Km |
The maximum distance unit of 100 energy is selected to carry out doppler frequency rate estimation:
1, the initial frequency modulation rate that each distance unit is calculated is as shown in Figure 4；
2, the tolerable doppler frequency rate worst error Δ k by being calculatedthr=1, therefore the initial stepping chosen is long
Degree is Δ k=4；
3, the process of breadth search is as shown in table 2:
The process of 2 breadth search of table
| Searching times | Node 1 | Node 2 | Node 3 | Contrast maximum node |
| 1 | -4 | 0 | 4 | Node 3 |
| 2 | 0 | 4 | 8 | Node 3 |
| 3 | 0 | 8 | 16 | Node 2 |
4, by breadth search, the doppler frequency rate deviation section [0,16] when contrast optimization focuses is had found, is connect
Get off and carry out deep search, the process of deep search is as shown in table 3:
The process of 3 deep search of table
| Searching times | Node 1 | Node 2 | Node 3 | Node 4 | Node 5 | Contrast maximum node |
| 1 | 0 | 4 | 8 | 12 | 16 | Node 4 |
| 2 | 8 | 10 | 12 | 14 | 16 | Node 2 |
| 3 | 8 | 9 | 10 | 11 | 12 | Node 2 |
| 4 | 8 | 8.5 | 9 | 9.5 | 10 | Node 4 |
5, in the 4th search, the difference of the doppler frequency rate deviation of the node of left and right two of node 4 is received with meeting
Condition is held back, therefore search terminates, the doppler frequency rate deviation being calculated is Δ ka=9.5, according to the deviation and initially
Doppler frequency rate value calculates the doppler frequency rate estimated value of each distance row, as shown in Figure 5.
It should be noted that above-described embodiment can be freely combined as needed.The above is only of the invention preferred
Embodiment, it is noted that for those skilled in the art, in the premise for not departing from the principle of the invention
Under, several improvements and modifications can also be made, these modifications and embellishments should also be considered as the scope of protection of the present invention.
Claims (10)
1. a kind of SAR doppler frequency rate estimation method characterized by comprising
Distance is carried out to compression to echo data, energy after compression according to distance unit is descending to be arranged successively, and is selected
The preceding M distance unit of arrangement is taken, remembers that the array of the M distance unit composition is xrc；
Calculate xrcIn each distance unit initial tune frequency values ka0, not according to the maximum phase error of SAR imaging tolerance
It requires to choose initial stepping length Δ k greater than the focusing accuracy of π/4；
The node {-Δ k, 0, Δ k } that 3 doppler frequency rate deviations are arranged carries out breadth search, and 3 nodes are successively denoted as node
1, node 2, node 3, using 3 nodes to xrcAzimuth Compression processing is carried out, and calculates the contrast value of 3 nodes；
When the contrast maximum of the node 2, breadth search terminates, and 3 nodes {-Δ k, 0, Δ k } are denoted as { Δ k10,Δ
k20,Δk30, carry out deep search；
According to { Δ k10,Δk20,Δk305 node { Δ k of construction1,Δk2,Δk3,Δk4,Δk5, utilize the more of 5 nodes
Pu Le tune frequency departure is to xrcAzimuth Compression processing is carried out, and calculates the contrast value of 5 nodes, wherein
If doppler frequency rate deviation Δ kiThe contrast of corresponding node is maximum, then according to Δ kiJudge doppler frequency rate
Whether restrain, the Δ kiFor { the Δ k1,Δk2,Δk3,Δk4,Δk5In any one；
Terminate deep search if convergence, obtains accurate doppler frequency rate deviation Δ ka；Otherwise 5 nodes are reconfigured
{Δk1',Δk2',Δk3',Δk4',Δk5' each node contrast is calculated, until doppler frequency rate is restrained；Wherein
2. SAR doppler frequency rate estimation method according to claim 1, which is characterized in that echo data carry out away from
Descriscent compression, the energy of n-th of distance unit after compression are as follows:
Wherein, N indicates total orientation points, and x (n, i) indicates i-th echo amplitude value of n-th of distance unit, and n is positive
Integer.
3. SAR doppler frequency rate estimation method according to claim 1, which is characterized in that xrcIn m-th of distance unit
Frequency modulation rate initial value ka0Are as follows:
Wherein, v is SAR platform movement velocity, and λ is signal wavelength, RmOblique distance for m-th of distance unit away from SAR platform, θsqFor
Imaging center moment angle of squint, 1≤m≤M, and m are positive integer；Wherein,
Wherein, RsFor center oblique distance, NrFor distance unit number, C is the light velocity, fsFor sample frequency；
Focusing accuracy requirement of the maximum phase error of SAR imaging tolerance no more than π/4, tolerable doppler frequency rate deviation
It is worth Δ kerrAre as follows:
Wherein, TaFor imaging cycle；
Take Δ kerrMaximum value be tolerable doppler frequency rate maximum deflection difference value Δ kthr, that is, have
Initial stepping length Δ k=(3~5) Δ kthr。
4. SAR doppler frequency rate estimation method according to claim 3, which is characterized in that xrcCarry out Azimuth Compression
Processing specifically includes:
The doppler frequency rate k of m-th of distance unit in each nodemFor doppler frequency rate initial value ka0(m) it is saved with corresponding
Doppler frequency rate deviation delta k in pointnThe sum of, Δ knFor {-Δ k, 0, Δ k } or { Δ k1,Δk2,Δk3,Δk4,Δk5Or
{Δk1',Δk2',Δk3',Δk4',Δk5' in any one；
Doppler frequency rate kmDistance unit Azimuth Compression reference function are as follows:
Wherein, taFor the orientation time, j indicates plural number, and exp is the power function using natural constant the bottom of as；
The treatment process of Azimuth Compression are as follows:
I(m,km)=abs (FFT (xrc(m)*sref(km)))
Wherein, xrcIt (m) is echo data xrcM-th of distance unit sample sequence, FFT is Fourier transformation, and abs expression takes
Absolute value, I (m, km) it is that m-th of distance unit uses doppler frequency rate kmFinish the Azimuth Compression image intensity that treated.
5. SAR doppler frequency rate estimation method according to claim 4, which is characterized in that xrcDegree of comparing meter
Calculator body includes:
Wherein, C (m, km) it is that m-th of distance unit uses doppler frequency rate kmCarry out the comparison being calculated after Azimuth Compression
Angle value, E expression take mean value；
The contrast value that all distance unit that each node Azimuth Compression obtains calculate is averaged respectively, the mean value is used as should
The contrast of node, i.e. doppler frequency rate deviation are Δ knThe contrast of corresponding node are as follows:
6. SAR doppler frequency rate estimation method according to claim 1, which is characterized in that SAR doppler frequency rate is estimated
Meter method further include:
When the contrast maximum of the node 1, is searched for negative direction, reconfigure three sections by step value of Δ k'=- Δ k
{ 0, Δ k', 2 Δ k'} are denoted as new node 1 to point, and new node 2, new node 3, carries out Azimuth Compression and contrast calculates；
Terminate breadth search if the contrast maximum of the new node 2, by { 0, Δ k', 2 Δ k'} are denoted as { Δ k10,Δk20,Δ
k30Carry out deep search；
If the contrast maximum of the new node 3 by the Δ of Δ k "=2 k' be step value reconfigure again three nodes 0, Δ
K ", 2 Δ k " } Azimuth Compression and contrast calculating are carried out, until the contrast maximum of node 2 terminates breadth search, carry out depth
Search.
7. SAR doppler frequency rate estimation method according to claim 1, which is characterized in that SAR doppler frequency rate is estimated
Meter method further include:
When the contrast maximum of the node 3, is searched for positive direction, reconfigure three sections by step value of Δ k'=Δ k
{ 0, Δ k', 2 Δ k'} are denoted as new node 1 to point, and new node 2, new node 3, carries out Azimuth Compression and contrast calculates；
Terminate breadth search if the contrast maximum of the new node 2, by { 0, Δ k', 2 Δ k'} are denoted as { Δ k10,Δk20,Δ
k30Carry out deep search；
If the contrast maximum of the new node 3 by the Δ of Δ k "=2 k' be step value reconfigure again three nodes 0, Δ
K ", 2 Δ k " } Azimuth Compression and contrast calculating are carried out, until the contrast maximum of node 2 terminates breadth search, carry out depth
Search.
8. SAR doppler frequency rate estimation method according to claim 3, which is characterized in that doppler frequency rate value is received
The condition held back are as follows: | Δ ki+1-Δki-1|≤Δkthr, wherein the value of i is 2,3 or 4, Δ kiFor the maximum node pair of contrast
The doppler frequency rate deviation answered；
When doppler frequency rate convergence, accurate doppler frequency rate deviation Δ kaAre as follows: Δ ka=(Δ ki+1+Δki-1)/2。
9. SAR doppler frequency rate estimation method according to claim 8, which is characterized in that SAR doppler frequency rate is estimated
Meter method further include:
After the completion of deep search, the doppler frequency rate estimated value of m-th of distance unit are as follows:
ka(m)=ka0(m)+Δka。
10. a kind of SAR doppler frequency rate estimating system characterized by comprising
Distance carries out distance to compression to compression module, to echo data, and the energy after compression according to distance unit is by big
It is arranged successively to small, chooses M distance unit before arranging, remember that the array of the M distance unit composition is xrc；
Computing module calculates xrcIn each distance unit initial tune frequency values ka0, according to the maximum phase of SAR imaging tolerance
Position error requires to choose initial stepping length Δ k no more than the focusing accuracy of π/4；
Analysis module, be arranged 3 doppler frequency rate deviations node {-Δ k, 0, Δ k } carry out breadth search, 3 nodes according to
It is secondary to be denoted as node 1, node 2, node 3, using 3 nodes to XrcAzimuth Compression processing is carried out, and calculates the contrast of 3 nodes
Value；
The analysis module, if the contrast of the node 2 is maximum, breadth search terminates, by three nodes-Δ k, 0, Δ
K } it is denoted as { Δ k10,Δk20,Δk30, carry out deep search；According to { Δ k10,Δk20,Δk305 node { Δ k of construction1,Δ
k2,Δk3,Δk4,Δk5, using the doppler frequency rate deviation of 5 nodes to xrcAzimuth Compression processing is carried out, and calculates 5
The contrast value of node, wherein
Control module, if doppler frequency rate deviation Δ kiThe contrast of corresponding node is maximum, then judges doppler frequency rate
Whether restrain, the Δ kiFor { the Δ k1,Δk2,Δk3,Δk4,Δk5In any one；If then terminating depth to search
Rope obtains accurate doppler frequency rate deviation Δ ka；Otherwise 5 node { Δ k are reconfigured1',Δk2',Δk3',Δ
k4',Δk5' each node contrast is calculated, until doppler frequency rate is restrained；Wherein
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110412625A (en) * | 2019-08-07 | 2019-11-05 | 北京北广科技股份有限公司 | A kind of follow-on code acquisition algorithm |
| CN112130145A (en) * | 2020-08-10 | 2020-12-25 | 西安电子科技大学 | Azimuth frequency modulation rate estimation method based on heterogeneous parallel computing |
| CN113126057A (en) * | 2021-04-20 | 2021-07-16 | 哈尔滨工业大学 | SAR motion compensation method based on frequency modulation rate estimation |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101414314A (en) * | 2007-10-17 | 2009-04-22 | 北京中电华大电子设计有限责任公司 | Method for improving running speed of integrated circuit simulator |
| CN102540188A (en) * | 2012-01-04 | 2012-07-04 | 西安电子科技大学 | Contrast optimization self-focusing method based on hypersonic platform synthetic aperture radar (SAR) |
| CN103457268A (en) * | 2013-09-17 | 2013-12-18 | 国家电网公司 | Optimal load curtailment control method based on parallel mode searching |
| CN103605953A (en) * | 2013-10-31 | 2014-02-26 | 电子科技大学 | Vehicle interest target detection method based on sliding window search |
| CN103690194A (en) * | 2013-12-17 | 2014-04-02 | 中国科学院深圳先进技术研究院 | Method and system for estimating flow velocity of blood flow based on broadband signal |
| CN104635214A (en) * | 2015-02-12 | 2015-05-20 | 西安电子科技大学 | Airborne forward-looking frequency diversity array radar distance fuzzy clutter suppression method |
| CN104808182A (en) * | 2015-04-13 | 2015-07-29 | 南京航空航天大学 | High-resolution wide-swath onboard SAR (synthetic aperture radar) real-time motion compensation algorithm |
| CN106353756A (en) * | 2016-11-25 | 2017-01-25 | 西安电子科技大学 | Descending track spotlight SAR (synthetic aperture radar) positioning method based on image matching |
-
2018
- 2018-10-16 CN CN201811202837.9A patent/CN109471100A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101414314A (en) * | 2007-10-17 | 2009-04-22 | 北京中电华大电子设计有限责任公司 | Method for improving running speed of integrated circuit simulator |
| CN102540188A (en) * | 2012-01-04 | 2012-07-04 | 西安电子科技大学 | Contrast optimization self-focusing method based on hypersonic platform synthetic aperture radar (SAR) |
| CN103457268A (en) * | 2013-09-17 | 2013-12-18 | 国家电网公司 | Optimal load curtailment control method based on parallel mode searching |
| CN103605953A (en) * | 2013-10-31 | 2014-02-26 | 电子科技大学 | Vehicle interest target detection method based on sliding window search |
| CN103690194A (en) * | 2013-12-17 | 2014-04-02 | 中国科学院深圳先进技术研究院 | Method and system for estimating flow velocity of blood flow based on broadband signal |
| CN104635214A (en) * | 2015-02-12 | 2015-05-20 | 西安电子科技大学 | Airborne forward-looking frequency diversity array radar distance fuzzy clutter suppression method |
| CN104808182A (en) * | 2015-04-13 | 2015-07-29 | 南京航空航天大学 | High-resolution wide-swath onboard SAR (synthetic aperture radar) real-time motion compensation algorithm |
| CN106353756A (en) * | 2016-11-25 | 2017-01-25 | 西安电子科技大学 | Descending track spotlight SAR (synthetic aperture radar) positioning method based on image matching |
Non-Patent Citations (4)
| Title |
|---|
| 曹攀: "高分辨ISAR成像中运动补偿技术研究", 《中国优秀硕士学位论文全文数据库》 * |
| 李舒 等: "2．2一种改进的机载合成孔径雷达最大对比度自聚焦算法", 《中国航空学会信号与处理专业第六届学术会议》 * |
| 杨建宇: "《双基合成孔径雷达》", 31 December 2017 * |
| 袁红峰 等: "基于启发式搜索的调频率估计算法", 《现代雷达》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110412625A (en) * | 2019-08-07 | 2019-11-05 | 北京北广科技股份有限公司 | A kind of follow-on code acquisition algorithm |
| CN112130145A (en) * | 2020-08-10 | 2020-12-25 | 西安电子科技大学 | Azimuth frequency modulation rate estimation method based on heterogeneous parallel computing |
| CN113126057A (en) * | 2021-04-20 | 2021-07-16 | 哈尔滨工业大学 | SAR motion compensation method based on frequency modulation rate estimation |
| CN113126057B (en) * | 2021-04-20 | 2022-09-16 | 哈尔滨工业大学 | SAR motion compensation method based on frequency modulation rate estimation |
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