CN110146891A - The irregular synthetic aperture radar image-forming method of single channel restored based on blind area data - Google Patents
The irregular synthetic aperture radar image-forming method of single channel restored based on blind area data Download PDFInfo
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- 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
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- 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
- G01S13/885—Radar or analogous systems specially adapted for specific applications for ground probing
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- 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
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- 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
- G01S7/414—Discriminating targets with respect to background clutter
Abstract
The invention discloses a kind of irregular synthetic aperture radar image-forming method of single channel restored based on blind area data, mainly solve not accounting for that grating lobe problem is imaged caused by blind area data is lost in the prior art.Its implementation are as follows: set pulse recurrence interval PRI sequence as increasing sequence, PRI sequence design formula is determined according to the parameter in target scene, solves PRI agile sequence；Then blind area data is restored using the method for interpolation of data；Resampling is carried out to the non-uniform sampling data after blind area data interpolation using nonuniform fast Fourier transform later；Imaging finally is carried out to it with tradition imaging algorithm.Design is optimized to PRI sequence in the present invention, effectively reduces the requirement in PRI sequence design methodology for system duty cycle, while solving grating lobe problem caused by blind area data lacks.It can be used for the irregular synthetic aperture radar image-forming of orientation single channel, obtain the imaging results to work well.
Description
Technical field
The invention belongs to image procossing and technical field, in particular to a kind of irregular synthetic aperture radar image-forming side of single channel
Method can be used for satellite-borne synthetic aperture radar earth observation.
Background technique
Spaceborne SAR energy round-the-clock, round-the-clock, high-resolution, big region earth observation, have become sky
Between earth observation main means, high-resolution and wide swath are the following important sides for improving satellite-borne SAR earth observation ability
To.
The spaceborne single-channel SAR system of tradition faces the contradiction of high-resolution and wide swath when carrying out high-resolution mapping.
Researcher proposes orientation multichannel, mosaic isotype to obtain high score wide cut earth observation ability thus.Orientation multi-pass
Road mode achievees the purpose that reduce pulse recurrence interval PRI and increases mapping band by increasing port number in orientation.Mosaic
Mode then needs to complete wide cut mapping by the complicated selection of wave position and the switching of wave position, but reduces mapping efficiency.
Currently, pitching multichannel combination digital bea mforming DBF technology, which can be used, obtains wide cut data, phase is carried out to it
Analysis is closed, discovery still has the blind area as caused by transmitting impulse disturbances, so that wide cut surveys and draws incomplete problem.In order to avoid
The influence of blind area, irregular synthetic aperture radar allow blind area in number using the relationship between PRI and blind area using PRI agile technology
It is no longer resident in the same area in the process according to admission, while substar echo is inhibited using DBF technology, may finally navigate in single
Whole scene mapping is completed in crossing, and has effectively expanded the mapping swath width of radar.Further refinement then has been carried out to this technology, and
A kind of PRI sequence design methodology to successively decrease is given, but this method, which sets clocking requirement system in progress PRI, has lower account for
Empty ratio, this will increase the peak power requirements of system transmitting, brings difficulty to hardware design.In addition, irregular synthetic aperture radar
During data recording PRI be variation, this will lead to the sampling of echo data in space be it is heterogeneous, therefore, ginseng
Traditional Space-borne SAR Imaging algorithm cannot be directly used when poor synthetic aperture radar image-forming.
The existing irregular synthetic aperture radar image-forming system of spaceborne single channel, it is necessary first to which uniform data are carried out to echo
Restore, then according still further to conventional imaging method carry out Range compress, range migration correction, orientation compression etc. operation, complete at
As processing.This method is in the presence of there are two main problems: first problem is irregular synthetic aperture radar in echo admission process
Middle PRI is variation, directly rebuilds uniform echo-signal using Based on Interpolating Spline, imaging results will appear false target.The
Two problems are the influence that the irregular synthetic aperture radar image-forming system of single channel does not account for blind area data loss, imaging results meeting
There is graing lobe.
Summary of the invention
It is an object of the invention in view of the deficiency of the prior art, propose it is a kind of based on blind area data restore
The irregular synthetic aperture radar image-forming method of single channel eliminates the graing lobe in imaging results to avoid the appearance of false target, improves
The quality of imaging.
To achieve the above object, technical solution of the present invention includes the following:
(1) pulse recurrence interval PRI agile sequence is designed:
(1a) sets total segments of pulse recurrence interval PRI sequence as N, and every section of PRI sequence is increasing function, and every section
The initial value of PRI sequence is PRI0(p), wherein N is integer greater than 0, p=0,1 ..., N-1, and according to same target point
The principle that continuous impulse is not lost derives the incremental change Δ in the length M and every section of PRI sequence of PRI sequence；
(1b) according to the requirement of system duty cycle, using the incremental change Δ in the length M and every section of PRI sequence of PRI sequence,
Obtain pulse recurrence interval PRI agile sequence: PRIm(p)=PRI0(p)+m Δ, wherein m=1...M-1；
(2) blind area data is restored using the method for interpolation of data:
(2a) sets scene objects echo time delay as τ1, fire pulse width τ, transmitting-receiving convert time delay into Δ τ, when echo
Prolong when being unsatisfactory for following formula, signal receiver can not obtain target scene echo, which shows as making an uproar after completing imaging
Sound, as blind area；
aPRIm(p)+τ+Δ τ < τ1< (a+1) PRIm(p)-Δτ
Wherein, a is the integer greater than 0；
(2b) according to the valid data region near blind area to blind area by the way of cubic spline interpolation, will be lacked at blind area
The data of mistake recover, and the echo data for recovering it is close to true value；
(3) imaging is carried out to the echo after recovery blind area data:
First the data after blind area data interpolation are carried out using nonuniform fast Fourier transform NUFFT tool in Matlab
Resampling obtains the data of orientation uniform sampling；Conventional synthesis aperture radar SAR imaging algorithm is reused, after resampling
Data be imaged.
Compared with prior art, the present invention having the following beneficial effects:
1) system duty cycle is high
The existing irregular synthetic aperture radar image-forming system of orientation single channel, due to using the PRI sequence design successively decreased, and
Clocking requirement system is set with lower duty ratio carrying out PRI, not only increases the peak power requirements of system transmitting, and
Difficulty is brought to hardware design, and what the present invention designed is a kind of incremental agile PRI sequence, both the higher system of tolerable accounted for
Empty ratio, and can utmostly keep the admission quality of echo data.
2) false target is avoided the occurrence of
The existing irregular synthetic aperture radar image-forming system of orientation single channel, due to not accounting for the presence of blind area, directly
Uniform sampling is carried out to echo-signal and reuses traditional imaging algorithm progress SAR imaging, imaging results will appear false target, and
The present invention has carried out the recovery of blind area data before carrying out uniform sampling to echo-signal first, avoids in imaging results and occurs
False target.
3) graing lobe in imaging results is eliminated
The existing irregular synthetic aperture radar image-forming system of orientation single channel, due to not carrying out data recovery to blind area,
Imaging results will appear because of graing lobe caused by blind area data lacks, and the present invention takes the mode of interpolation of data, utilizes blind area
Similitude between perimeter data and blind area data, interpolation obtain blind area data, and graing lobe caused by blind area echo data lacks obtains
To effectively eliminating.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with
It obtains other drawings based on these drawings.
Fig. 1 is implementation flow chart of the invention；
Fig. 2 is the sub-process figure in the present invention to echo data imaging；
Fig. 3 is the PRI sequence results figure designed with the existing PRI sequence design methodology that successively decreases when duty ratio is 5%；
Fig. 4 is the PRI sequence results figure designed with the present invention when duty ratio is 5%；
Fig. 5 is the PRI sequence results G- Design result figure designed with the present invention when duty ratio is 10%；
Fig. 6 is the point target reflectogram that imaging is used in emulation experiment；
Fig. 7 is the result figure being imaged with existing method and the present invention.
Specific embodiment
Below in conjunction with drawings and examples, elaborate to the embodiment of the present invention and effect.
In order to avoid the influence of blind area, the irregular synthetic aperture radar of this example using pulse recurrence interval PRI and blind area it
Between relationship, allow blind area to be no longer resident in the same area during data recording using PRI agile technology, while using DBF
Technology inhibits substar echo, and whole scene mapping is finally completed in single navigated, has effectively expanded the mapping swath width of radar.
Referring to Fig.1, the specific implementation steps are as follows for this example:
Step 1: design pulse recurrence interval PRI agile sequence.
(1a) sets total segments of pulse recurrence interval PRI sequence as N, and every section of PRI sequence is increasing function, and every section
The initial value of PRI sequence is PRI0(p), wherein N is the integer greater than 0, p=0,1 ..., N-1；
(1b) derives the incremental change Δ in the length M and every section of PRI sequence of PRI sequence:
The principle that (1b1) does not lose according to same target point continuous impulse obtains the design formula in refinement PRI sequence:
In formula, c is the light velocity, fire pulse width τ, R1,R2The respectively corresponding nearest and farthest oblique distance of observation scene,
k*It walks to stop assuming the umber of pulse of lower scene nearest oblique distance echo arrival time and emission time interval to be non-:
Wherein,For downward bracket function, PRI0For the initial value of PRI sequence；
(1b2) solves PRI sequence formula, obtains the length M of the incremental change Δ of PRI and PRI sequence in every section of PRI sequence:
Firstly, according to the umber of pulse k of scene nearest oblique distance echo arrival time and emission time interval*, obtain every section of PRI
The incremental change Δ of PRI in sequence:
Then, each section of PRI sequence length is solved:
Wherein, M (p) indicates pth section PRI sequence length, PRI0(p) PRI is originated for pth section,For the function that rounds up,
K* (p) is that the non-of pth section walks to stop assuming the umber of pulse of lower scene nearest oblique distance echo arrival time and emission time interval:
Finally, obtaining the length of PRI sequence according to the length of each section of PRI sequence:
M=∑ M (p), p=0,1 ..., N-1；
Incremental change Δ in the length M for the PRI sequence that (1c) is obtained according to upper step and every section of PRI sequence, obtains pulse weight
It is spaced PRI agile sequence again:
PRIm(p)=PRI0(p)+m Δ, wherein m=1...M-1；
Step 2: blind area data is restored using the method for interpolation of data.
In high score wide cut earth observation, when improving azimuth resolution, the doppler bandwidth of echo-signal can mention therewith
Height, in order to guarantee echo-signal not fuzzy sampled, PRI can be decreased accordingly, and mapping swath width also accordingly narrows, this can lead
It causes to will appear blind area in mapping band, the influence that blind area enrolls echo data and is imaged all is very serious.Traditional orientation
The irregular synthetic aperture radar image-forming algorithm of single channel does not account for the problem of blind area data lacks, and directly carries out to echo data
Irnaging procedures are carried out after uniform sampling, imaging results will appear the graing lobe due to caused by blind area data missing, so restoring blind
The operation of area's data is necessary.
The recovery of blind area data is carried out by the way of interpolation, the mode of interpolation of data in addition to cubic spline interpolation with
Outside, there are also closest interpolation and bilinear interpolations etc..Closest interpolation method is fastest, but error is than cubic spline interpolation
As a result big, and interpolation result is rough；Bilinear interpolation method is using the gray value of four neighbor points of surrounding in both direction
On do linear interpolation and obtain the gray value of sampled point, but this method becomes more to obscure on edge；Cubic spline interpolation
Result it is relatively smooth, will not be obscured on edge, therefore, this example has selected the mode with cubic spline interpolation, in fact
It is now as follows:
(2a) sets scene objects echo time delay as τ1, fire pulse width τ, transmitting-receiving convert time delay into Δ τ, when echo
Prolong when being unsatisfactory for following formula, signal receiver can not obtain target scene echo, which shows as making an uproar after completing imaging
Sound, as blind area；
aPRIm(p)+τ+Δ τ < τ1< (a+1) PRIm(p)-Δτ
Wherein, a is the integer greater than 0；
(2b) restores the data lacked at blind area:
(2b1) uses cubic spline interpolation to blind area according to the valid data region near blind area, the one of echo data
It is the data of n that orientation valid data region, which takes a segment length, if the data distribution is cubic spline function S (x), and should
Data are divided into n-1 section [xi,xi+1], i=0,1 ..., n-1, S (x) are cubic polynomials on each minizone；
(2b2) is by the endpoint x of the n data and section that are takeniIt is updated to the S for indicating the cubic polynomial in every section of sectioni
(x) in:
Si(x)=ai+bi(x-xi)+ci(x-xi)2+di(x-xi)3
Wherein, x indicates n taken data value, ai,bi,ci,diIndicate four numerical value differences of cubic polynomial equation
Coefficient, be amount to be solved；
N data value is updated to S by (2b3) respectivelyi(x) in equation, with n equation solution Si(x) coefficient in equation
ai,bi,ci,di, the function expression in every section of section is obtained, so that the data of blind area part in every section be calculated.
Step 3: imaging is carried out to the echo after recovery blind area data.
Traditional imaging method has range Doppler RD imaging algorithm, and linear frequency modulation becomes mark CS imaging algorithm etc..RD imaging
Algorithm is the migration amount for calculating every migration curve, and by every migration curve calibration one by one, and CS algorithm is compared to RD algorithm,
The difference that the migration curve of different distance door is eliminated in the way of becoming target enables these curves become one group of migration amount identical
Curve can uniformly remove range migration, and CS algorithm ratio RD algorithm is more convenient on range migration correction, therefore, this example
CS algorithm has been used to carry out imaging.
Referring to Fig. 2, this step is implemented as follows:
(3a) using nonuniform fast Fourier transform NUFFT tool in Matlab to the data after blind area data interpolation into
Row resampling obtains the data of orientation uniform sampling；
(3b) uses conventional synthesis aperture radar SAR imaging algorithm, and the data after resampling are imaged:
Using CS imaging algorithm, the data after resampling are imaged, i.e., echo-signal is first done distance to compression and
Compressed data are taken turns doing orientation Fourier transformation and become and marked by secondary range compression；Range migration correction is done to it again,
And carry out orientation compression；Compressed data are done into orientation inverse Fourier transform operation again, obtain final imaging results.
Effect of the invention is explained again below with reference to two emulation experiments.
Emulation experiment one: pulse recurrence interval PRI sequence design is emulated.
(1) in segments N=7, PRI0(6)=0.285ms, downwards angle of visibility range are 23.3 °~40.5 °, orbit altitude is
Under the parameter of 760km, existing PRI sequence design methodology design of Simulation PRI sequence under conditions of duty ratio 5% of successively decreasing is used
Column, for simulation result as shown in figure 3, wherein Fig. 3 (a) is the PRI sequence of design, Fig. 3 (b) is that ground blind area changes schematic diagram, Fig. 3
It (c) is adjacent admission inter-pulse time interval, Fig. 3 (d) is RL return loss rate；
(2) in segments N=7, PRI0(6)=0.285ms, downwards angle of visibility range are 23.3 °~40.5 °, orbit altitude is
Under the parameter of 760km, using improvement PRI sequence design methodology proposed by the present invention under conditions of duty ratio 5% design of Simulation
PRI sequence, for simulation result as shown in figure 4, wherein Fig. 4 (a) is the PRI sequence of design, Fig. 4 (b) is the variation signal of ground blind area
Figure, Fig. 4 (c) are adjacent admission inter-pulse time interval, and Fig. 4 (d) is RL return loss rate；
(3) in segments N=7, PRI0(6)=0.285ms, downwards angle of visibility range are 23.3 °~40.5 °, orbit altitude is
Under the parameter of 760km, using improvement PRI sequence design methodology proposed by the present invention under conditions of duty ratio 10% design of Simulation
PRI sequence, for simulation result as shown in figure 5, wherein Fig. 5 (a) is the PRI sequence of design, Fig. 5 (b) is the variation signal of ground blind area
Figure, Fig. 5 (c) are adjacent admission inter-pulse time interval, and Fig. 5 (d) is RL return loss rate.
From figure 3, it can be seen that existing descending series available PRI sequence for meeting condition when duty ratio is 5%,
And when duty ratio be 10% when, PRI sequence design will appear without solution the case where.
As can be seen from Figure 4 and Figure 5, the method for the present invention can obtain the condition of satisfaction in duty ratio 5%, 10%
PRI sequence.Comparison diagram 3 (d) and Fig. 4 (d) successively decrease PRI sequence design methodology when duty ratio is 5%, average data loss late
About 7.1%, and method average data loss late proposed by the present invention is about 4.3%.Therefore sequence optimisation proposed by the present invention
Design method is in addition to that can tolerate higher system duty cycle, additionally it is possible to utmostly keep the admission quality of echo data.
Emulation experiment two: the imaging for restoring blind area data is emulated.
Having for the irregular synthetic aperture radar image-forming algorithm of single channel of blind area data recovery is verified by MATLAB emulation
Effect property.Main system emulation parameter is as shown in table 1, and echo used in imaging is as shown in fig. 6, wherein black in emulation experiment
Color region is echo free space domain, and horizontal axis is distance to the longitudinal axis is orientation.
The existing method 1 that this experiment is selected is to compress to the advanced row distance of echo data, then carries out uniform data sampling,
SAR imaging is finally completed, existing method 2 is that uniform data sampling is completed before Range compress, then completes SAR imaging.
1 simulation parameter of table
SAR imaging is carried out to the echo of Fig. 6 with method proposed by the present invention and two existing methods respectively, as a result such as
Shown in Fig. 7, wherein Fig. 7 (a) is the orientation impulse response figure of 1 imaging results of existing method, and Fig. 7 (b) is the imaging of existing method 2
As a result orientation impulse response figure, Fig. 7 (c) are the orientation impulse response figure of the method for the present invention imaging results.
Apparent blind area variation is lost with echo caused by blind area as seen from Figure 6.The area elliptica come is marked out in Fig. 7
Domain is graing lobe position, from the azimuth focus result of Fig. 7 (a) and Fig. 7 (b) it is found that the imaging knot of existing method 1 and existing method 2
There is graing lobe in fruit, from Fig. 7 (c) it can be seen that graing lobe is effectively eliminated, illustrate effectiveness of the invention.
Performance Evaluation is carried out to the SAR image that three kinds of imaging schemes obtain, it is other to compare its respective peak sidelobe ratio, integral
Valve when main lobe broadening ratio, as a result such as table 2.
2 three kinds of imaging scheme imaging performances of table
From table 2 it can be seen that effect of the present invention in imaging and focusing increases compared to two kinds of traditional algorithms.
In conclusion the invention proposes a kind of sides of irregular synthetic aperture radar image-forming restored based on blind area data
Method not only proposes a kind of design of incremental PRI sequence, can tolerate bigger system duty cycle relative to conventional method,
Reduce hardware design difficulty, and aiming at the problem that blind area data loss can cause imaging results graing lobe occur, using in data
Slotting method has restored blind area data, effectively inhibits the appearance of graing lobe, improves imaging performance.What is carried out in MATLAB is imitative
True experiment demonstrates the validity of method of the invention compared to conventional process algorithm.
Above description is only example of the present invention, does not constitute any limitation of the invention, it is clear that for
It, can be without departing substantially from the principle of the invention, structure after having understood the content of present invention and principle for one of skill in the art
In the case where, carry out various modifications and change in form and details, but these modifications and variations based on inventive concept
Still within the scope of the claims of the present invention.
Claims (4)
1. a kind of irregular synthetic aperture radar image-forming method of single channel restored based on blind area data, which is characterized in that including such as
Under:
(1) pulse recurrence interval PRI agile sequence is designed:
(1a) sets total segments of pulse recurrence interval PRI sequence as N, and every section of PRI sequence is increasing function, every section of PRI sequence
The initial value of column is PRI0(p), wherein N is integer greater than 0, p=0,1 ..., N-1, and according to the continuous arteries and veins of same target point
The principle that punching is not lost derives the incremental change Δ in the length M and every section of PRI sequence of PRI sequence；
(1b) is obtained according to the requirement of system duty cycle using the incremental change Δ in the length M and every section of PRI sequence of PRI sequence
Pulse recurrence interval PRI agile sequence: PRIm(p)=PRI0(p)+m Δ, wherein m=1...M-1；
(2) blind area data is restored using the method for interpolation of data:
(2a) sets scene objects echo time delay as τ1, fire pulse width τ, transmitting-receiving converts time delay as Δ τ, when echo time delay not
When meeting following formula, signal receiver can not obtain target scene echo, which shows as noise after completing imaging, i.e.,
For blind area；
aPRIm(p)+τ+Δ τ < τ1< (a+1) PRIm(p)-Δτ
Wherein, a is the integer greater than 0；
(2b) according to the valid data region near blind area to blind area by the way of cubic spline interpolation, by what is lacked at blind area
Data recover, and the echo data for recovering it is close to true value；
(3) imaging is carried out to the echo after recovery blind area data:
First the data after blind area data interpolation are adopted again using nonuniform fast Fourier transform NUFFT tool in Matlab
Sample obtains the data of orientation uniform sampling；Conventional synthesis aperture radar SAR imaging algorithm is reused, to the number after resampling
According to being imaged.
2. the method as described in claim 1, which is characterized in that the original that do not lost in (1a) according to same target point continuous impulse
It then obtains the incremental change Δ in the length M and every section of PRI sequence of PRI sequence, is accomplished by
The principle that (1a1) does not lose according to same target point continuous impulse is obtained in refinement PRI sequence design formula:
C is the light velocity, k in formula*It walks to stop assuming the pulse of lower scene nearest oblique distance echo arrival time and emission time interval to be non-
Number；R1,R2The respectively corresponding nearest and farthest oblique distance of observation scene；
(1a2) solves PRI in the length M and every section of PRI sequence of PRI sequence according to PRI sequence design formula, by following formula
Incremental change Δ:
M=∑ M (p), p=0,1 ..., N-1
In formula, N is total segments of PRI sequence, k*For it is non-walk stop assuming lower scene nearest oblique distance echo arrival time and transmitting when
The umber of pulse at interval is carved,M (p) is pth section PRI sequence length,
Wherein, PRI0(p) PRI, PRI are originated for pth section0For the initial value of PRI sequence,For the function that rounds up, k*(p) it is
The non-of pth section walks to stop assuming the umber of pulse of lower scene nearest oblique distance echo arrival time and emission time interval,Wherein,For
Downward bracket function.
3. the method as described in claim 1, which is characterized in that according to the valid data region near blind area to blind area in (2b)
By the way of cubic spline interpolation, restores the data lacked at blind area, be accomplished by
It is the data of n that (2b1), which takes a segment length in an orientation valid data region of echo data, if the data distribution is
Cubic spline function S (x), and divide that data into n-1 section [xi,xi+1], i=0,1 ..., n-1, S (x) is in each cell
Between on be all cubic polynomial；
(2b2) is by the endpoint x of the n data and section that are takeniIt is updated to the S for indicating the cubic polynomial in every section of sectioni(x) in:
Si(x)=ai+bi(x-xi)+ci(x-xi)2+di(x-xi)3
Wherein, x indicates n taken data value, ai,bi,ci,diIt indicates four coefficients of cubic polynomial equation, is to be solved
Amount；
N data value is updated to S by (2b3) respectivelyi(x) in equation, the coefficient a in equation is solvedi,bi,ci,di, obtain every
The function expression in section section, so that the data of blind area part in every section be calculated.
4. the method as described in claim 1, which is characterized in that (3) conventional synthesis aperture radar SAR imaging algorithm is used in,
Data after resampling are imaged, are first to do distance to echo-signal to compression and secondary range compression, it will be compressed
Data do orientation Fourier transformation；Range migration correction is done to it again, by signal focus to same range gate, and the side of progress
Position is to compression；Compressed data are done into orientation inverse Fourier transform operation again, obtain final imaging results.
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| CN110927716A (en) * | 2019-12-11 | 2020-03-27 | 中国航空工业集团公司沈阳飞机设计研究所 | Radar scanning terrain blind spot and blind spot shielding determination method thereof |
| CN112014840A (en) * | 2020-07-30 | 2020-12-01 | 西安空间无线电技术研究所 | On-orbit implementation design method of satellite-borne SAR mosaic mode |
| CN116594014A (en) * | 2023-04-28 | 2023-08-15 | 南京航空航天大学 | Implementation method and implementation device for sparse Mosaic imaging mode |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040056794A1 (en) * | 2002-06-05 | 2004-03-25 | Radmila Erkocevic-Pribic | Irregular PRT deconvolution method and systems, and its uses |
| CN105929400A (en) * | 2016-05-25 | 2016-09-07 | 中国科学院遥感与数字地球研究所 | Accurate measurement-based flight speed variable airborne SAR (synthetic aperture radar) data compensation method under constant PRF (pulse repetition frequency) |
| CN106199602A (en) * | 2016-08-31 | 2016-12-07 | 电子科技大学 | A kind of Staggered SAR echo signal method for reconstructing |
-
2019
- 2019-07-02 CN CN201910590289.XA patent/CN110146891A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040056794A1 (en) * | 2002-06-05 | 2004-03-25 | Radmila Erkocevic-Pribic | Irregular PRT deconvolution method and systems, and its uses |
| CN105929400A (en) * | 2016-05-25 | 2016-09-07 | 中国科学院遥感与数字地球研究所 | Accurate measurement-based flight speed variable airborne SAR (synthetic aperture radar) data compensation method under constant PRF (pulse repetition frequency) |
| CN106199602A (en) * | 2016-08-31 | 2016-12-07 | 电子科技大学 | A kind of Staggered SAR echo signal method for reconstructing |
Non-Patent Citations (5)
| Title |
|---|
| MICHELANGELO VILLANO ET AL.: "Staggered SAR:High-Resolution Wide-Swath Imaging by Continuous PRI Variation", 《IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING》 * |
| XIANGYU WANG ET AL.: "SAR Signal Recovery and Reconstruction in Staggered Mode With Low Oversampling Factors", 《IEEE GEOSCIENCE AND REMOTE SENSING LETTERS》 * |
| 刘艳阳等: "一种星载多通道高分辨率宽测绘带SAR系统通道相位偏差估计新方法", 《电子与信息学报》 * |
| 王沛等: "星载大斜视聚束SAR变PRI成像技术研究", 《电子与信息学报》 * |
| 邹江波: "捷变PRF合成孔径雷达数据重建方法研究", 《中国优秀博硕士学位论文全文数据库(硕士)信息科技辑》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110927716A (en) * | 2019-12-11 | 2020-03-27 | 中国航空工业集团公司沈阳飞机设计研究所 | Radar scanning terrain blind spot and blind spot shielding determination method thereof |
| CN110927716B (en) * | 2019-12-11 | 2023-02-28 | 中国航空工业集团公司沈阳飞机设计研究所 | Radar scanning terrain blind spot and blind spot shielding determination method thereof |
| CN112014840A (en) * | 2020-07-30 | 2020-12-01 | 西安空间无线电技术研究所 | On-orbit implementation design method of satellite-borne SAR mosaic mode |
| CN116594014A (en) * | 2023-04-28 | 2023-08-15 | 南京航空航天大学 | Implementation method and implementation device for sparse Mosaic imaging mode |
| CN116594014B (en) * | 2023-04-28 | 2024-02-09 | 南京航空航天大学 | Implementation method and implementation device for sparse Mosaic imaging mode |
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