CN103762412A - Onboard downward-looking 3D SAR sparse array antenna laying method - Google Patents

Abstract

The invention provides an onboard downward-looking 3D SAR sparse array antenna laying method. The method aims to solve the problems that according to onboard 3D SAR system antenna laying, a platform installation space is limited and a design method is complicated; according to the flight height of an aerial carrier, an observation area maximum height change range function, a radar system work wavelength and a resolution ratio in the array direction, antenna laying design is carried out. The method is simple in operation, free of complicated computation and capable of guaranteeing that a grating lobe of a target response function in the array direction of a system is controlled to be at a reasonable level.

Description

Under airborne, look 3D SAR thinned array antenna layout method

Technical field

The present invention relates under airborne look 3D SAR thinned array antenna layout method.

Background technology

Under airborne, look array 3D SAR (Three-Dimensional Synthetic Aperture Radar is called for short 3D SAR) by territory, machine base area is observed, in direction of wave travel, by means of pulse compression, realize and differentiating; At course made good, by means of the motion of carrier aircraft platform, realize aperture synthesis, and then realize course made good and differentiate; Array to, by arranging that along carrier aircraft wing and ventral thinned array antenna realizes aperture synthesis, and then realize array to differentiating (referring to non-patent literature 1,2).

If be evenly arranged a large amount of antenna submatrixs along wing and ventral, to the pneumatic property of aircraft etc., can affect greatly on the one hand.On the other hand, be evenly arranged a large amount of array element and also can increase system cost and system complexity.For these problems, those skilled in the art have carried out a large amount of research work with regard to how carrying out array to antenna submatrix layout, for example, in non-patent literature 3,4,5, disclose following method.By M transmission antenna unit and N reception antenna unit virtual M * N displaced phase center, and the spacing in the middle of phase center need to be less than half-wavelength.But said method need to be take bay as omnidirectional antenna is prerequisite, can cover array to all targets that can observe.

Yet in actual observation, due to the restriction of system signal noise ratio, resolution etc., the array of system is always limited in certain observation scope to observation scope, rather than array is to ± 90 °.

In addition, in above-mentioned antenna submatrix layout, not yet consider that actual antennas array is to layout relationship between the antenna installing space on size, flying platform and antenna submatrix, there will be antenna at course made good, to be staggered front to back the situation of layout, particularly part transmitting antenna and the overlapping layout of reception antenna equivalent aerial, so be unfavorable for that system realizes, and is also unfavorable for the flexible installation of antenna on flying platform.

In addition,, in the antenna arrangement of prior art, array element layout is not yet considered the impact of target elevation scope.And then, also need to guarantee that systems array is controlled at reasonable level to the graing lobe of response function.

Non-patent literature:

Non-patent literature 1:J.Klare.A newairborne radar for3D imaging-simulation study of ARTINO.EUSAR Dresden, Germany, 2006; W.M, E.J, E.A.Peters O.An airborneradar for three dimensionalimaging and observationtechnical realisation and status ofARTINO.EUSAR, Dresden, Germany, 2006.

Non-patent literature 2:L.Du, Y.P.Wang, W.Hong, et al.A Three-Dimensional range migration algorithm for downward-looking3D-SAR with single-transmitting and multiple-receiving linear array antennas.EURASIP Journal on Advances in Signal Processing, 2010.

Non-patent literature 3:J.Klare, D.Cerutti-Maori, A.Brenner, J.Ender.Image quality analysis of the vibrating sparse MIMO antenna array of the airborne3D imaging radar ARTINO.2007.

Non-patent literature 4:M.Weiss, O.Peters, J.Ender.A three-dimensional SAR system on an UAV.IGARSS2007, Barcelona, Spain, 2008:5315-5318.

Non-patent literature 5: Peng Xueming, Wang Yanping, Tan Weixian, etc. based on looking MIMO3D-SAR three-dimensional imaging algorithm across under course thinned array airborne. electronics and information journal, 2012,34 (4): 943-949.

Summary of the invention:

(1) technical problem that will solve

For the problems referred to above of the prior art, the invention provides and a kind ofly look 3D SAR thinned array antenna layout method under airborne, solved and looked in 3D SAR imaging array under airborne to problems such as antenna arrangement method for designing complexity and antenna arrangement limited space, particularly can to resolution and observation scope, carry out array according to systems array and design to antenna arrangement, and can guarantee that systems array is controlled at reasonable level to the graing lobe of response function.

(2) technical scheme

To achieve these goals, of the present inventionly look 3D SAR thinned array antenna layout method under airborne, comprising:

Step S1, according to carrier aircraft flying height, observation area maximum height excursion function, radar system operation wavelength, azimuth resolution and array as looking 3D SAR system parameters under airborne, to resolution, determine that array antenna orientation is to size, array to antenna arrangement length and array antenna unit half beam width;

Step S2, to antenna arrangement length and described array antenna unit half beam width, determines that transmission antenna unit array is to size, transmission antenna unit spacing and reception antenna cell array to size based on described array;

Step S3, according to described array, to antenna arrangement length and described transmission antenna unit spacing, calculate transmission antenna unit number, reception antenna unit number, reception antenna unit interval, transmitting antenna geometric center position distribution and reception antenna cell geometry center and distribute;

Step S4, half beam width according to described carrier aircraft flying height and from described array to antenna element, set up array to sampling point position coordinate, utilize described array to sampling point position coordinate, described carrier aircraft flying height and described radar system operation wavelength, determine that the array of point target under System Computer is to response function f{X (k)-x ₀and the array of edge, observation area target to response function $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\θ}}_L}\right)]\×\tan \left({\mathrm{\θ}}_L\right)+x_0\left\}\right\};$

Step S5, under described System Computer, the array of point target is to response function f{X (k)-x ₀and the array of edge, described observation area target to response function $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\θ}}_L}\right)]\×\tan \left({\mathrm{\θ}}_L\right)+x_0\left\}\right\}$ Graing lobe drop on system imaging observation area ± q _loutside, and

time, execution step S6, under described System Computer, the array of point target is to response function f{X (k)-x ₀and the array of edge, described observation area target to response function $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\θ}}_L}\right)]\×\tan \left({\mathrm{\θ}}_L\right)+x_0\left\}\right\}$ Graing lobe drop on described system imaging observation area ± q _lwithin, or

time, make described reception antenna unit number add one, and be back to step S3, wherein, H is described carrier aircraft flying height, L _efor array is to antenna arrangement effective aperture length, l _cfor described radar system operation wavelength, r _lfor described array is to resolution;

Step S6, exports described array antenna direction size L _a, described transmission antenna unit array to size, described transmission antenna unit number, described transmitting antenna geometric center position distribution, described transmission antenna unit array to size, described reception antenna unit number and described reception antenna cell geometry center distribute; With

Step S7, according to the layout parameter of exporting in described step S6, carries out described layout of looking 3DSAR thinned array antenna under airborne.

(3) invention effect

According to the present invention, take radar system index and actual observation scope is input, consider that actual antennas array is to layout relationship between the antenna installing space on size, flying platform and antenna submatrix, solve conventional antenna and at course made good, be staggered front to back the situation of layout, particularly part transmitting antenna and the overlapping layout of reception antenna equivalent aerial, be conducive to the flexible installation of antenna on flying platform; In addition, array element layout has been considered the impact of target elevation scope, and compared with prior art, the method is simple to operate, without complicated calculations, can be effectively applied to radar system design.

Accompanying drawing explanation

Fig. 1 means the flow chart of looking 3D SAR thinned array antenna layout method under airborne in embodiments of the present invention.

Fig. 2 means the step of carrying out antenna arrangement based on determined antenna arrangement parameter in embodiments of the present invention.

Fig. 3 mean based in embodiments of the present invention definite antenna arrangement parameter carry out the schematic diagram of antenna arrangement.

Embodiment

For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in more detail.

It should be noted that, in accompanying drawing or specification description, similar or identical part is all used identical drawing reference numeral.The implementation that does not illustrate in accompanying drawing or describe is form known to a person of ordinary skill in the art in affiliated technical field.In addition, although the demonstration of the parameter that comprises particular value can be provided herein, should be appreciated that, parameter is without definitely equaling corresponding value, but can in acceptable error margin or design constraint, be similar to corresponding value.In addition, the direction term of mentioning in following examples, such as " on ", D score, 'fornt', 'back', " left side ", " right side " etc., be only the direction with reference to accompanying drawing.Therefore, the direction term of use is to be not used for limiting the present invention for illustrating.

In one exemplary embodiment of the present invention, provide a kind of and looked 3D SAR thinned array antenna layout method under airborne.Fig. 1 represents to look under airborne in embodiments of the present invention the flow chart of 3D SAR thinned array antenna layout method.As shown in Figure 1, under the present embodiment airborne, depending on 3D SAR thinned array antenna layout method, comprise:

Step S1: according to carrier aircraft flying height H, the observation area maximum height excursion function h as looking 3D SAR system parameters under airborne _t(x), radar system operation wavelength l _c, azimuth resolution r _awith array to resolution r _l, computing array antenna bearingt is to size L _a, array is to antenna arrangement length L and array antenna unit half beam width q _l;

Wherein x represents that array is to target location variable, x=[H-h _t(x)] * tan (θ _x), θ _x∈ [θ _l,+θ _l], depending on 3D SAR system parameters, mainly comprise carrier aircraft flying height H, observation area maximum height excursion function h under airborne _t(x), radar system operation wavelength l _cwith array to resolution r _l;

Step S2: according to array to antenna arrangement length L and array antenna unit half beam width q _lcalculate transmission antenna unit array to size l _t, transmission antenna unit space D l _t, reception antenna cell array is to size l _r:

$l_T=\frac{l_c}{\tan \left({2q}_L\right)}{K}_b;$

${\mathrm{Dl}}_T=\frac{l_c}{\tan \left({2q}_L\right)}{K}_b;$

$l_R=\frac{l_c}{\tan \left({2q}_L\right)}{K}_b;$

Wherein, K _bfor beamwidth coefficient, relevant to the CURRENT DISTRIBUTION on antenna aperture, common K _b=0.886;

Step mule S3: according to array to antenna arrangement length L and transmission antenna unit space D l _tcalculate transmission antenna unit and count M, reception antenna unit number N, reception antenna unit interval Dl _r, transmitting antenna geometric center position distribution L _tx(m), m=1,2 ..., M and reception antenna cell geometry center distribution L _rx(n), n=1,2 ..., N;

Step S4: according to antenna element geometric center position distribution L _x, array is to the half beam width q of antenna element _lwith radar system operation wavelength l _cpoint target f{X (k)-x under computing system machine ₀and the array of edge, observation area target to response function $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\θ}}_L}\right)]\×\tan \left({\mathrm{\θ}}_L\right)+x_0\left\}\right\},$ Wherein,

for corresponding q _ltime target location coordinate, x _npoint target position coordinates under expression machine, X (k) be array to sampling point position coordinate, under machine, point target array to coordinate is

also equal array to antenna arrangement center;

Step S5: at array to response function f{X (k)-x ₀and $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\θ}}_L}\right)]\×\tan \left({\mathrm{\θ}}_L\right)+x_0\left\}\right\}$ Graing lobe drop on system imaging observation area ± q _loutside, and time, wherein, L _efor array is to antenna arrangement effective aperture length, l _cfor radar system operation wavelength, r _lfor array is to resolution, H is carrier aircraft flying height,

for corresponding q _ltime target location coordinate, perform step S6; At array to response function f{X{ (k)-x ₀and $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\θ}}_L}\right)]\×\tan \left({\mathrm{\θ}}_L\right)+x_0\left\}\right\}$ Graing lobe drop on system imaging observation area ± q _lwithin, or

time, wherein

for corresponding q _ltime target location coordinate, make reception antenna unit number N add 1, and be back to step S3;

Step S6: export under airborne and look 3D SAR thinned array antenna layout parameter, comprise array antenna direction size L _a, transmission antenna unit array is to size l _t, transmission antenna unit counts M, transmitting antenna geometric center position distribution L _tx(m), m=1,2 ..., M, reception antenna cell array are to size l _r, reception antenna unit number N and reception antenna cell geometry center distribution L _rx(n), n=1,2 ..., N.

Step S7: according in step S6, export airborne under look 3D SAR thinned array antenna layout parameter, carry out the layout of looking 3D SAR thinned array antenna under airborne.

In addition, above-mentioned step S1 also comprises following step:

Step S11: according to carrier aircraft flying height H, radar system operation wavelength l _cazimuth resolution r _awith array to resolution r _lcomputing array antenna bearingt is to size L _awith array to antenna arrangement length L:

$L=\frac{l_{c}H}{{2r}_L}$

$L_A=\frac{l_{c}H}{{2r}_A}$

The array antenna orientation here comprises that to size transmission antenna unit orientation is to size and orientation, reception antenna unit to size, and the orientation of two kinds of antennas equates to size, is L _a.

Step S12: according to carrier aircraft flying height H, observation area maximum height excursion function h _t(x), radar system operation wavelength l _cwith array to imaging fabric width W _lcomputing array is to the half beam width q of antenna element _l:

${\mathrm{\θ}}_L=\max \{a\tan \left(\frac{W_L}{2H}\right),a\tan \left(\frac{x}{2(H-\max \left(h_T\left(x\right)\right))}\right)\}$

Wherein, x represents that array is to target location variable, x=H * tan (θ _x), θ _x∈ [θ _l,+θ _l], for corresponding q _ltarget location coordinate, max represents to get maximum.

In addition, above-mentioned step S3 also comprises following step:

Step S31: if executed step S5 forwards step S32 to; If not yet perform step S5, according to array to antenna arrangement length L and transmission antenna unit space D l _tcalculate transmission antenna unit and count M and reception antenna unit number N:

Wherein, a represents transmission antenna unit number variable, and b represents reception antenna unit number variable, Δ l _trepresent transmission antenna unit spacing,

bracket function in expression, represent lower bracket function, M and N are respectively positive integer, and min (2a+b) represents the minimum of getting (2a+b);

Step S32: count M, reception antenna unit number N and transmission antenna unit space D l according to transmission antenna unit _tcalculate reception antenna unit interval Dl _r:

${\mathrm{Dl}}_R=\frac{{\mathrm{Dl}}_T}{2}M$

Step S33: count M, reception antenna unit number N, transmission antenna unit space D l according to transmission antenna unit _twith reception antenna unit interval Dl _rcalculate under airborne and look transmitting antenna geometric center position distribution L _tx(m), m=1,2 ..., M and reception antenna cell geometry center distribution L _rx(n), n=1,2 ..., N:

$\left\{\begin{array}{c}{L}_{\mathrm{Rx}}\left(n\right)={\mathrm{\&Delta;l}}_R\&times;n,n=1,2,...,N;\\ L_{\mathrm{Tx}}\left(m\right)=\left\{\begin{array}{c}{L}_{\mathrm{Rx}}\left(1\right)-{\mathrm{\&Delta;l}}_T\&times;m;m=\mathrm{1,2},...,\frac{\mathrm{<figure-callout\; id="2"\; label="M"\; filenames="HDA0000451970490000031.png"\; state="\{\{state\}\}">M</figure-callout>}}{2};\\ L_{\mathrm{Rx}}\left(N\right)+{\mathrm{\&Delta;l}}_T\&times;(m-\frac{M}{2});m=(\frac{\mathrm{<figure-callout\; id="2"\; label="M"\; filenames="HDA0000451970490000031.png"\; state="\{\{state\}\}">M</figure-callout>}}{2}+1),...,M;\end{array}\right.\end{array}\right.$

Wherein, Dl _rfor reception antenna unit interval, Dl _tfor transmission antenna unit spacing.

Step S34: the L obtaining according to step S33 _rxand L (n) _tx(m) generate array to antenna arrangement effective aperture length L _ewith virtual displaced phase center L _tRx(q), q=1, L, MN:

$L_e=\frac{L_{\mathrm{Tx}}\left(M\right)+L_{\mathrm{Rx}}\left(N\right)}{2}-\frac{L_{\mathrm{Tx}}\left(1\right)+L_{\mathrm{Rx}}\left(1\right)}{2};$

for?n＝1∶N，

for?m＝1∶M，

$L_{\mathrm{TRx}}[q=(n-1)\&times;N+m]=\frac{L_{\mathrm{Rx}}\left(n\right)+L_{\mathrm{Tx}}\left(m\right)}{2}$

end；

end；

L _rxand L (n) _tx(m) loop successively between any two antenna phase center equivalence, obtain altogether MN antenna displaced phase center.

In addition, above-mentioned step S4 also comprises following several steps:

Step S41: the half beam width q according to carrier aircraft flying height H and array to antenna element _lset up array to sampling point position coordinate

wherein,

with

on representing respectively, round and under round, Dl _tfor transmission antenna unit spacing,

for array is to antenna arrangement center, q _lfor the half beam width of array to antenna element;

Step S42: according to carrier aircraft flying height H, radar system operation wavelength l _cthe array of determining point target under System Computer to sampling point position coordinate X (k) with array is to response function f{X (k)-x ₀and the array of edge, observation area target to response function $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\&theta;}}_L}\right)]\&times;\tan \left({\mathrm{\&theta;}}_L\right)+x_0\left\}\right\}:$

$\begin{array}{c}f\{X\left(k\right)-x_1\}{|}_{x_1=x_0}\\ =\underset{q=1}{\overset{\mathrm{MN}}{\mathrm{\&Sigma;}}}\begin{array}{c}\exp (-j4\mathrm{\&pi;}\frac{\sqrt{{[X\left(k\right)-x_1]}^2+{[H-h_T\left(x_1\right)]}^2}}{{\mathrm{\&lambda;}}_c})\\ \&times;\exp (+j4\mathrm{\&pi;}\frac{\sqrt{{[L_{\mathrm{TRx}}\left(q\right)-x_1]}^2+{[H-h_T\left(x_1\right)]}^2}}{{\mathrm{\&lambda;}}_c})\end{array}\end{array}$

$\begin{array}{c}f\{X\left(k\right)-x_1\}{|}_{x_1=\left\{\right[H-h_T\left(x_{{\mathrm{\&theta;}}_L}\right)]\&times;\tan \left({\mathrm{\&theta;}}_L\right)+x_0\}}\\ =\underset{q=1}{\overset{\mathrm{MN}}{\mathrm{\&Sigma;}}}\begin{array}{c}\exp (-j4\mathrm{\&pi;}\frac{\sqrt{{[X\left(k\right)-x_1]}^2+{[H-h_T\left(x_1\right)]}^2}}{{\mathrm{\&lambda;}}_c})\\ \&times;\exp (+j4\mathrm{\&pi;}\frac{\sqrt{{[L_{\mathrm{TRx}}\left(q\right)-x_1]}^2+{[H-h_T\left(x_1\right)]}^2}}{{\mathrm{\&lambda;}}_c})\end{array}\end{array}$

Wherein, x ₁represent that array is to target location coordinate, L _tRx(q) be virtual displaced phase center q=1, L, MN, $f\{X\left(k\right)-x_0\}=f\{X\left(k\right)-x_1\}{|}_{x_1=x_0},$

$f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\&theta;}}_L}\right)]\&times;\tan \left({\mathrm{\&theta;}}_L\right)+x_0\left\}\right\}=f\{X\left(k\right)-x_1\}{|}_{x_1=\left\{\right[H-h_T\left(x_{{\mathrm{\&theta;}}_L}\right)]\&times;\tan \left({\mathrm{\&theta;}}_L\right)+x_0\}}.$

Fig. 2 represents that the antenna arrangement parameter based on definite in above-mentioned execution mode of the present invention carries out looking under airborne the step of 3D SAR thinned array antenna layout.Fig. 3 represent based in embodiments of the present invention definite antenna arrangement parameter carry out the schematic diagram of antenna arrangement.

Utilize said method to calculate transmission antenna unit array to size l _t, transmission antenna unit counts M, transmitting antenna geometric center position distribution L _tx(m), m=1,2 ..., M, reception antenna cell array are to size l _r, reception antenna unit number N and reception antenna cell geometry center distribution L _rx(n), n=1,2 ..., N, above-mentioned step S7 also comprises following step:

Step S71: determine antenna arrangement parameter list, determined antenna arrangement parameter list is as shown in table 1;

Table 1

Array antenna layout parameter	Symbol
		Array antenna orientation is to size	L A
Transmission antenna unit array is to size	l T
		Transmission antenna unit number	M
Transmitting antenna geometric center position distribution	L Tx(m)
		Reception antenna cell array is to size	l R
Reception antenna unit number	N
		Reception antenna cell geometry center distributes	L Rx(n)

Step S72: determine antenna arrangement gauge point according to antenna arrangement parameter list, select to treat layout platform, according to transmitting antenna geometric center position distribution L _tx(m) determine the transmitting antenna gauge point that platform can layout, and be labeled as PosT (mt), mt=1 wherein ..., M, according to reception antenna cell geometry center distribution L _rx(n) determine the reception antenna gauge point that platform can layout, and be labeled as PosR (nr), nr=1 wherein ..., N;

Step S73: transmitting antenna and reception antenna are arranged, can layout transmitting antenna gauge point PosT and reception antenna gauge point PosR according to platform, the principle that transmitting antenna and reception antenna are overlapped with gauge point according to geometric center is arranged respectively transmitting antenna and reception antenna.

Above embodiments of the present invention are illustrated, under airborne, look 3D SAR thinned array antenna layout method, based on radar system index and actual observation scope, consider that actual antennas array is to layout relationship between the antenna installing space on size, flying platform and antenna submatrix, can solve conventional antenna and at course made good, be staggered front to back the situation of layout, particularly avoid part transmitting antenna and the overlapping layout of reception antenna equivalent aerial, be conducive to the flexible installation of antenna on flying platform.

Above-described specific embodiment; object of the present invention, technical scheme and beneficial effect are further described; institute is understood that; the foregoing is only specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any modification of making, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.

Claims (6)

1. under airborne, look a 3D SAR thinned array antenna layout method, it is characterized in that, comprising:

Step S1, according to carrier aircraft flying height, observation area maximum height excursion function, radar system operation wavelength, azimuth resolution and array as looking 3D SAR system parameters under airborne, to resolution, determine that array antenna orientation is to size, array to antenna arrangement length and array antenna unit half beam width;

Step S2, to antenna arrangement length and described array antenna unit half beam width, determines that transmission antenna unit array is to size, transmission antenna unit spacing and reception antenna cell array to size based on described array;

Step S3, according to described array, to antenna arrangement length and described transmission antenna unit spacing, calculate transmission antenna unit number, reception antenna unit number, reception antenna unit interval, transmitting antenna geometric center position distribution and reception antenna cell geometry center and distribute;

Step S4, half beam width according to described carrier aircraft flying height and from described array to antenna element, set up array to sampling point position coordinate, utilize described array to sampling point position coordinate, described carrier aircraft flying height and described radar system operation wavelength, determine that the array of point target under System Computer is to response function f{X (k)-x ₀and the array of edge, observation area target to response function

$f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\&theta;}}_L}\right)]\&times;\tan \left({\mathrm{\&theta;}}_L\right)+x_0\left\}\right\};$

Step S5, under described System Computer, the array of point target is to response function f{X (k)-x ₀and the array of edge, described observation area target to response function $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\&theta;}}_L}\right)]\&times;\tan \left({\mathrm{\&theta;}}_L\right)+x_0\left\}\right\};$ Graing lobe drop on system imaging observation area ± q _loutside, and

time, execution step S6, under described System Computer, the array of point target is to response function f{X (k)-x ₀and the array of edge, described observation area target to response function $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\&theta;}}_L}\right)]\&times;\tan \left({\mathrm{\&theta;}}_L\right)+x_0\left\}\right\}$ Graing lobe drop on described system imaging observation area ± q _lwithin, or

time, make described reception antenna unit number add one, and be back to step S3, wherein, H is described carrier aircraft flying height, L _efor array is to antenna arrangement effective aperture length, l _cfor described radar system operation wavelength, r _lfor described array is to resolution;

Step S6, exports described transmission antenna unit array and distributes to size, described reception antenna unit number and described reception antenna cell geometry center to size, described transmission antenna unit number, described transmitting antenna geometric center position distribution, described reception antenna cell array;

Step S7, according to the layout parameter of exporting in described step S6, carries out described layout of looking 3DSAR thinned array antenna under airborne.

2. according to claim 1ly look 3D SAR thinned array antenna layout method under airborne, it is characterized in that,

In described step S1,

Described carrier aircraft flying height is being made as to H, described radar system operation wavelength is being made as to l _c, described array is made as to r to resolution _l, described azimuth resolution is made as to r _a, described array antenna azimuth dimension is made as to L _a, when described array is made as to L to antenna arrangement length,

$L=\frac{l_{c}H}{{2r}_L}$

$L_A=\frac{l_{c}H}{{2r}_A}$

Described observation area maximum height excursion function is being made as to h _t(x), described array is made as to W to imaging fabric width _l, described array is made as to q to the half beam width of antenna element _ltime,

${\mathrm{\&theta;}}_L=\max \{a\tan \left(\frac{W}{2H}\right),a\tan \left(\frac{x}{2(H-\max \left(h_T\left(x\right)\right))}\right)\},$

Wherein, x represents that array is to target location variable, x=H * tan (θ _x), θ _x∈ [θ _l,+θ _l], for corresponding q _ltarget location coordinate.

3. according to claim 1ly look 3D SAR thinned array antenna layout ten thousand methods under airborne, it is characterized in that,

In described step S2, described radar system operation wavelength is being made as to l _c, described array antenna unit half beam width is made as to q _l, described transmission antenna unit array is made as to l to size _t, described transmission antenna unit spacing is made as to Dl _t, described reception antenna cell array is made as to l to size _rtime,

$l_T=\frac{l_c}{\tan \left({2q}_L\right)}{K}_b;{\mathrm{Dl}}_T=l_T;l_R=\frac{l_c}{\tan \left({2q}_L\right)}{K}_b;$

Wherein, K _bfor beamwidth coefficient, relevant to the CURRENT DISTRIBUTION on antenna aperture, set K _b=0.886.

4. according to claim 1ly look 3D SAR thinned array antenna layout method under airborne, it is characterized in that,

In described step S3, also comprise:

Step S31, if executed step S5 forwards step S32 to; If not yet perform step S5, according to described array to antenna arrangement length and described transmission antenna unit space D l _t, determine described transmission antenna unit number and described reception antenna unit number,

Described array is being made as to L, described transmission antenna unit spacing is being made as to Dl to antenna arrangement length _t, by described transmission antenna unit number be made as M, when described reception antenna unit number is made as to N,

Wherein, a represents transmission antenna unit number variable, and b represents reception antenna unit number variable, Al _trepresent transmission antenna unit spacing,

bracket function in expression, represent lower bracket function, M and N are respectively positive integer, and min (2a+b) represents the minimum of getting (2a+b);

Step S32, utilizes described transmission antenna unit number and described transmission antenna unit spacing in described step S31, determines described reception antenna unit interval, and described reception antenna unit interval is being made as to Dl _rtime,

${\mathrm{Dl}}_R=\frac{{\mathrm{Dl}}_T}{2}M,$

Wherein, Dl _tfor described transmission antenna unit spacing, M is described transmission antenna unit number;

Step S33, according to described transmission antenna unit number, described reception antenna unit number, described transmission antenna unit spacing and described reception antenna unit interval, determines transmitting antenna geometric center position distribution L _tx(m) L _tx(m), m=1,2 ..., M and reception antenna cell geometry center distribution L _rx(n) L _rx(n), n=1,2 ..., N,

$\left\{\begin{array}{c}{L}_{\mathrm{Rx}}\left(n\right)={\mathrm{\&Delta;l}}_R\&times;n,n=1,2,...,N;\\ L_{\mathrm{Tx}}\left(m\right)=\left\{\begin{array}{c}{L}_{\mathrm{Rx}}\left(1\right)-{\mathrm{\&Delta;l}}_T\&times;m;m=\mathrm{1,2},...,\frac{M}{2};\\ L_{\mathrm{Rx}}\left(N\right)+{\mathrm{\&Delta;l}}_T\&times;(m-\frac{M}{2});m=(\frac{M}{2}+1),...,M;\end{array}\right.\end{array}\right.$

Wherein, M is that described transmission antenna unit number, N are described reception antenna unit number, Dl _tfor transmission antenna unit spacing, Dl _rfor reception antenna unit interval.

5. according to claim 4ly look 3D SAR thinned array antenna layout method under airborne, it is characterized in that,

Utilize described reception antenna cell geometry center distribution L _rxand described transmitting antenna geometric center position distribution L (n) _tx(m), generate array to antenna arrangement effective aperture length and virtual displaced phase center, described reception antenna cell geometry center distribution L _rxand described transmitting antenna geometric center position distribution L (n) _tx(m) loop successively between any two antenna phase center equivalence, obtain altogether MN antenna displaced phase center.

6. according to claim 1ly look 3D SAR thinned array antenna layout method under airborne, it is characterized in that,

In described step S4, when described array is made as to X (k) to sampling point position coordinate,

$X\left(k\right)=x_0+\frac{{\mathrm{\&Delta;l}}_T}{2}\&times;k,k=-K,...,\mathrm{0,1},...,K,$

Wherein,

with

represent respectively upper bracket function and lower bracket function, represent that array is to antenna arrangement center, Dl _tfor transmission antenna unit spacing, q _lfor the half beam width of array to antenna element;

Utilize described array to sampling point position coordinate X (k), calculate the array of point target under described System Computer to response function f{X (k)-x ₀and the array of edge, described observation area target to response function $f\{X\left(k\right)-\{[H-h_T\left(x_{{\mathrm{\&theta;}}_L}\right)]\&times;\tan \left({\mathrm{\&theta;}}_L\right)+x_0\left\}\right\}$ Time,

$\begin{array}{c}f\{X\left(k\right)-x_1\}{|}_{x_1=x_0}\\ =\underset{q=1}{\overset{\mathrm{MN}}{\mathrm{\&Sigma;}}}\begin{array}{c}\exp (-j4\mathrm{\&pi;}\frac{\sqrt{{[X\left(k\right)-x_1]}^2+{[H-h\left(x_1\right)]}^2}}{{\mathrm{\&lambda;}}_c})\\ \&times;\exp (+j4\mathrm{\&pi;}\frac{\sqrt{{[L_{\mathrm{TRx}}\left(q\right)-x_1]}^2+{[H-h\left(x_1\right)]}^2}}{{\mathrm{\&lambda;}}_c})\end{array}\end{array}$

$\begin{array}{c}f\{X\left(k\right)-x_1\}{|}_{x_1=\left\{\right[H-h_T\left(x_{{\mathrm{\&theta;}}_L}\right)]\&times;\tan \left({\mathrm{\&theta;}}_L\right)+x_0\}}\\ =\underset{q=1}{\overset{\mathrm{MN}}{\mathrm{\&Sigma;}}}\begin{array}{c}\exp (-j4\mathrm{\&pi;}\frac{\sqrt{{[X\left(k\right)-x_1]}^2+{[H-h\left(x_1\right)]}^2}}{{\mathrm{\&lambda;}}_c})\\ \&times;\exp (+j4\mathrm{\&pi;}\frac{\sqrt{{[L_{\mathrm{TRx}}\left(q\right)-x_1]}^2+{[H-h\left(x_1\right)]}^2}}{{\mathrm{\&lambda;}}_c})\end{array}\end{array}$

Wherein, H is described carrier aircraft flying height, l _cfor described radar system operation wavelength, x ₁for Target Aerial Array is to position coordinates.

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