CN101477199A - Rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar - Google Patents

Abstract

The utility model provides a synthetic aperture laser imaging radar's rectangle light wedge array telescope antenna, its constitution is rectangle light wedge array, objective, eyepiece, spectroscope, rectangle aperture photoelectric detector array, rectangle aperture laser emitter array and speculum in proper order, rectangle light wedge array be located the preceding focal plane of objective, rectangle aperture photoelectric detector array be located the back focal plane of eyepiece, rectangle aperture laser emitter array be located the back focal plane of eyepiece, the spectroscope to coming from rectangle aperture laser emitter array or the light beam that comes from objective and entering rectangle aperture photoelectric detector array carry out the beam splitting combination, the focus of objective be f₁The focal length of the eyepiece is f₂The distance between the objective lens and the ocular lens is f₁+f₂. The invention is used as an optical receiving and transmitting antenna, and can generate scanning strips with large width and azimuth high-resolution imaging.

Description

The rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar

Technical field

The present invention relates to synthetic aperture laser imaging radar, is a kind of rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar, receives and emitting antenna as optics, can produce the scanning band of big width and orientation to high-resolution imaging.

Background technology

The principle of synthetic aperture laser imaging radar (SAIL) is taken from the theory of SAR of RF application, is to obtain unique optical imagery Observations Means of centimetre magnitude resolution at a distance.The optics toes yardstick on target face that is determined by emission laser divergence and heterodyne reception directivity is the optical diffraction limit of telescope objective, because the optical frequency wavelength is very for a short time to be generally about the micron number magnitude, the optics toes are narrower, and this is the intrinsic problem of synthetic aperture laser imaging radar.The U.S. has the people to propose a kind of improvement project (list of references 1), use small-bore laser transmitting system to produce big target illumination zone, adopt the small-bore hyperchannel optics system of multiple aperture multidetector to realize that the large tracts of land echoed signal receives simultaneously, thereby realize big width scan band, but may realize hardly on this methods engineering.Be the list of references of existing relevant synthetic aperture laser imaging radar below:

(1)R.L.Lucke，M.Bashkansky，J.Reintjes，and?F.Funk，“Synthetic?aperture?ladar(SAL)：fundamental?theory，design?equations?for?a?satellite?system，and?laboratorydemonstration，”NRL/FR/7218—02-10，051，Naval?Research?Laboratory，Dec.26，2002.

(2)W.Buell，N.Marechal，J.Buck，R.Dickinson，D.Kozlowski，T.Wright，and?S.Beck，“Demonstration?of?synthetic?aperture?imaging?ladar，”Proc.of?SPIE，Vol.5791，PP.152-166(2005).

(3)J.Ricklin，M.Dierking，S.Fuhrer，B.Schumm，and?D.Tomlison，“Synthetic?apertureladar?for?tactical?imaging，”DARPA?Strategic?Technology?Office.

(4) Liu Liren, synthetic aperture laser imaging radar (I): out of focus and phase bias telescope receiving antenna [J], optics journal, 2008,28 (5): 997-1000.

(5) Liu Liren, synthetic aperture laser imaging radar (II): space phase bias emission telescope [J], optics journal, 2008,28 (6): 1197-1200.

(6) Liu Liren, synthetic aperture laser imaging radar (III): bidirectional loop transmitting-receiving telescope for synthesis [J], optics journal, 2008,28 (7): 1405-1410.

Summary of the invention

The object of the present invention is to provide a kind of rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar.The rectangular aperture telescope receives as optics and emitting antenna can produce the rectangular optical toes that meet the synthetic aperture laser imaging radar scan mode, can access uniform orientation to imaging resolution, particularly can control respectively laser radar optics toes the orientation to and vertical direction on yardstick, thereby control optics toes yardstick and imaging resolution.The optical telescope antenna that rectangular optical wedge array is arranged can obtain the scanning band of big width with the arrange optics toes of each sub-aperture generation of reasonable manner.Therefore the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar receives and emitting antenna as optics, can produce the scanning band of big width and orientation to high-resolution imaging.

Technical solution of the present invention is as follows:

A kind of rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar, be characterized in: the formation of described rectangular optical wedge array telescope comprises rectangular optical wedge array, object lens, eyepiece, spectroscope, the rectangular aperture photodetector array, rectangular aperture generating laser array and catoptron, described rectangular optical wedge array, object lens, eyepiece, spectroscope, rectangular aperture generating laser array in turn is positioned on the light path, described rectangular optical wedge array is positioned at the front focal plane of described object lens, described rectangular aperture photodetector array is positioned at the back focal plane of described eyepiece, described rectangular aperture generating laser array is positioned at the back focal plane of described eyepiece, described rectangular aperture photodetector array and described catoptron lay respectively on the reflected light path on described spectroscopical two sides, and the focal length of described object lens is f ₁, the focal length of described eyepiece is f ₂, the distance between described object lens and the described eyepiece is f ₁+ f ₂, this telescopical enlargement factor is $M=\frac{f_1}{{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="A200910045638E00141.png"\; state="\{\{state\}\}">f</figure-callout>}}_2},$ Described spectroscope is to from the light beam of described rectangular aperture generating laser array, carry out the beam splitting combination from the light beam of object lens and the light beam that enters described rectangular aperture photodetector array.

Described rectangular optical wedge array telescope is when receiving optical antenna, described rectangular optical wedge array and object lens are in the face of target, described rectangular optical wedge array is the receiving telescope entrance pupil, described spectroscope reflexes to described rectangular aperture photodetector array to echo beam, and each unit rectangular optical wedge on the described rectangular optical wedge array and the corresponding one by one imaging of unit rectangular detector on the described rectangular aperture photodetector array: the length of side of each unit rectangular optical wedge in the described rectangular optical wedge array is respectively l _x, l _y, the cycle between the unit rectangular optical wedge is L _y, L satisfies condition _y〉=l _y, the yardstick of the unit rectangular detector on the described rectangular aperture photodetector array is l _{X, r}, l _{Y, r}, satisfy $\frac{l_x}{l_{x,r}}=\frac{l_y}{l_{y,r}}=M.$

Described rectangular optical wedge array telescope is during as the transmitting optics antenna, described rectangular aperture generating laser array is gone out Laser emission by described rectangular optical wedge array, and the corresponding one by one imaging of each unit rectangular optical wedge on the unit rectangular shaped light source on the described rectangular aperture generating laser array and the described rectangular optical wedge array: the length of side of each unit rectangular optical wedge in the described rectangular optical wedge array is respectively l _x, l _y, the cycle between the unit rectangular optical wedge is L _y, L satisfies condition _y〉=l _y, the yardstick of the unit rectangular shaped light source on the described rectangular aperture generating laser array is l _{X, t}, l _{Y, t}, satisfy $\frac{l_x}{l_{x,t}}=\frac{l_y}{l_{y,t}}=M;$ Described spectroscope reflexes to described catoptron to the part light intensity of described rectangular aperture generating laser array, return again and arrive described rectangular aperture photodetector array by described spectroscope, as the local oscillation array of source that optical heterodyne receives, each unit rectangular shaped light source of at this moment described rectangular aperture generating laser array is corresponding one by one with the unit rectangular detector on the described rectangular aperture photodetector array: the yardstick l of the unit rectangular shaped light source on the described rectangular aperture generating laser array _{X, t}, l _{Y, t}Respectively with described rectangular aperture photodetector array on the yardstick l of unit rectangular detector _{X, r}, l _{Y, r}Equate.

Described rectangular optical wedge array is made of 2K+1 unit rectangular optical wedge, wherein K=0, ± 1, ± 2, ± 3 ... ± K, the unit rectangular optical wedge of K=0 is dull and stereotyped wedge, and the drift angle of K module unit rectangular optical wedge is K a times of basic drift angle, and the length of side of described unit rectangular optical wedge is respectively l _x, l _y, the cycle between the unit rectangular optical wedge is L _y, basic drift angle is: ${\mathrm{\&Delta;\&theta;}}_y=\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="A200910045638E00141.png"\; state="\{\{state\}\}">P</figure-callout>}\frac{2\mathrm{\&lambda;}}{(n-1)l_y},$ Described l _xBy object plane illumination width $\mathrm{\&delta;\&alpha;}=\frac{2\mathrm{\&lambda;z}}{l_x}$ Decision, l _yBy the scan stripes bandwidth ${\mathrm{\&delta;\&beta;}}_k=\frac{2\mathrm{\&lambda;z}}{l_y}$ Decision, and scan stripes bandwidth ${\mathrm{\&delta;\&beta;}}_k=\frac{2\mathrm{\&lambda;z}}{l_y}$ With the resolution diameter $\mathrm{\&delta;d}=\frac{D}{N}$ The span of ratio be generally 10 ²～10 ³, the overlap distance width of object plane illumination is: $\mathrm{\&Delta;\&beta;}=((K-1)P+1)\frac{2\mathrm{\&lambda;z}}{l_y},$ In the formula: D is the telescopical diameter of the present invention, and N expresses the equivalent radius-of-curvature f of final orientation to phase place quadratic term course _FtAnd the constant that concerns between the target range z, P is an overlap factor, and K is an aperture number, and λ is a wavelength, and n is the refractive index of glass rectangular optical wedge, the unit rectangular optical wedge of described rectangular optical wedge array (1) puts in order arbitrarily.

Described rectangular optical wedge array by K=0, ± 1, ± 2, ± 3 ... ,+(K-2) ,+(K-1) ,+the asymmetric a plurality of unit rectangular optical wedge of k constitutes.

Described rectangular optical wedge array is placed directly in described object lens front, but simultaneously places field lens on described object lens back focal plane, and compensation is owing to described rectangular optical wedge array leaves the additive phase quadratic term that the distance of the front focal plane of described object lens produces.

The xsect of the unit rectangular optical wedge of described rectangular optical wedge array is the right-angle triangle with chamfering, trapezoidal or equilateral triangle.

Described each unit rectangular shaped light source of rectangular aperture generating laser array is the coherent array laser light source, or incoherent array laser light source.

Each unit rectangular shaped light source emitted laser of described rectangular aperture generating laser array is a plane wave, or Elliptical Gaussian Beam.

Technique effect of the present invention:

Adopt the antenna of rectangular optical wedge array telescope antenna of the present invention, have following characteristics as synthetic aperture laser imaging radar:

(1) optical telescope of single rectangular aperture can produce the rectangular optical toes as reception of the optics in the synthetic aperture laser imaging radar and emitting antenna, any impact point all experiences equal scanning pattern, and therefore the optical telescope of rectangular aperture of the present invention meets the synthetic aperture laser imaging radar scan mode.

(2) the emission beam divergence of rectangular aperture antenna and optical heterodyne receiving directivity function all be the orientation to and vertical direction on the variables separation function, the yardstick of two length of sides of rectangular aperture that can designing optimal control respectively laser radar optics toes the orientation to and vertical direction on yardstick, obtain exposing thoroughly width and orientation are to high resolving power.

(3) the optical telescope antenna arranged of rectangular optical wedge array can be with reasonable manner each sub-aperture of arranging, and the optics toes of generation obtain the scanning band of big width.Therefore the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar receives and emitting antenna as optics, can produce the scanning band of big width and orientation to high-resolution imaging.

Description of drawings

Fig. 1 is the system schematic of the rectangular aperture telescope antenna of synthetic aperture laser imaging radar of the present invention.

Embodiment

Below in conjunction with drawings and Examples the present invention is described in further detail:

See also Fig. 1 earlier, Fig. 1 is the system schematic of the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar of the present invention.Fig. 1 also is the system schematic of one embodiment of the present of invention.As seen from the figure, the formation of the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar of the present invention is rectangular optical wedge array 1, object lens 2, eyepiece 3, spectroscope 4, rectangular aperture photodetector array 5, rectangular aperture generating laser array 6 and catoptron 7 successively

Described rectangular optical wedge array 1 is positioned at the front focal plane of described object lens 2, described rectangular aperture photodetector array 5 is positioned at the back focal plane of described eyepiece, described rectangular aperture generating laser array 6 is positioned at the back focal plane of described eyepiece, described spectroscope 4 is positioned at the back of described eyepiece 3, described spectroscope 4 is positioned at the front of rectangular aperture photodetector array 5, described spectroscope 4 is positioned at the front of rectangular aperture generating laser array 6, and the focal length of described object lens 2 is f ₁, the focal length of described eyepiece 3 is f ₂, the distance between described object lens 2 and the described eyepiece 3 is f ₁+ f ₂, this telescopical enlargement factor is $M=\frac{f_1}{{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="A200910045638E00141.png"\; state="\{\{state\}\}">f</figure-callout>}}_2}.$ It is that dull and stereotyped wedge with K=0 is a benchmark that the unit rectangular optical wedge of the rectangular optical wedge array 1 of this embodiment puts in order, divide and press the arrangement of K incremental order up and down, K upwards〉1 positive dirction increases the wedge angle successively, and K＜1 increases successively in the other direction that the wedge angle arranges downwards.

Telescope is when receiving optical antenna, described rectangular optical wedge array 1 and object lens 2 are in the face of target, described rectangular optical wedge array 1 is the receiving telescope entrance pupil, described spectroscope 4 reflexes to described rectangular aperture photodetector array 5 to echo beam, the corresponding one by one imaging of unit rectangular detector on unit rectangular optical wedge on the described rectangular optical wedge array 1 and the described rectangular aperture photodetector array 5.

Telescope is during as the transmitting optics antenna, the laser that described rectangular aperture generating laser array 6 is sent is launched by described rectangular optical wedge array 1, rectangular optical wedge corresponding one by one imaging in unit on rectangular laser source, unit on the described rectangular aperture generating laser array 6 and the described rectangular optical wedge array 1, described spectroscope 4 reflexes to described catoptron 7 to the part light intensity of described rectangular aperture generating laser array 6, return again and arrive described rectangular aperture photodetector array 5 by described spectroscope 4, as the local oscillation array of source that optical heterodyne receives, the rectangular laser source, unit of at this moment described rectangular aperture generating laser array 6 is corresponding one by one with the unit rectangular detector on the described rectangular aperture photodetector array 5.

In fact, telescope need carry out the compensation (list of references 4) of space quadratic term phase place when receiving optical antenna, telescope can be controlled during as the transmitting optics antenna producing suitable phase place quadratic term course (list of references 5), and telescope need adopt the bi-directional ring structure to implement phase compensation and biasing (list of references 6) respectively during simultaneously as receiving antenna and emitting antenna.The telescope that the present invention sets can meet above-mentioned service condition.Therefore, final orientation is to the equivalent radius-of-curvature f of phase place quadratic term course _FtCan be expressed as:

$\frac{1}{f_{\mathrm{ft}}}=\frac{1}{f_r}+\frac{1}{f_t}+\frac{1}{f_{\mathrm{add}}},$

Wherein: f _rThe radius-of-curvature of the phase history component that produces when receiving for echo, f _tThe radius-of-curvature of the phase history component that produces for the emission light beam, f _AddIt is the radius-of-curvature of the additive phase course component of transmitter-telescope space phase biasing generation.F is for example arranged in the territory, Fraunhofer diffraction region and when not considering additional biasing _Ft=f _t=z (list of references 5).For for simplicity, adopt constant N to express f _FtAnd the relation between the z:

$N=\frac{z}{f_{\mathrm{ft}}}=\frac{z}{f_r}+\frac{z}{f_t}+\frac{z}{f_{\mathrm{add}}}.$

The orientation generally can adopt following formula to estimate to imaging resolution

$\mathrm{\&delta;d}=\frac{D}{N},$

Wherein: D is the optical antenna diameter.

Be that example is done the labor explanation to the present invention below with the present embodiment:

Make that impact point is the z direction to the direction of laser radar, center of antenna is the x direction along the radar azimuth direction that moves, and its vertical direction is the y direction, thus world coordinates be (x, y, z).The length of side of each unit rectangular optical wedge in the rectangular optical wedge array 1 is respectively l _x, l _y, the ratio of the length of side is defined as $S_1=\frac{l_x}{l_y},$ Cycle between the wedge is L _y, therefore the center of k wedge is at (x=0, y=kL _y), L wherein must satisfy condition _y〉=l _yThe local coordinate system of ° k wedge is set at (x _k, y _k, z _k), satisfy coordinate system transformation relation (x _k=x, y _k=y-kL _y, z _k=z), so its true origin is at (x=0, y=kL _y, z=0).The yardstick of the unit rectangular shaped light source on the rectangular aperture generating laser array 6 is l _{X, t}, l _{Y, t}, then must satisfy $\frac{l_x}{l_{x,t}}=\frac{l_y}{l_{y,t}}=M.$ The yardstick of the unit rectangular detector on the rectangular aperture photodetector array 5 is l _{X, r}, l _{Y, r}, then must satisfy $\frac{l_x}{l_{x,r}}=\frac{l_y}{l_{y,r}}=M.$

Telescope can be summarized as follows as the function of transmitting optics antenna:

Telescope is during as the transmitting optics antenna, and the light field of the normalization emission laser that k rectangular aperture wedge light source in the output face of rectangular optical wedge array 1 produces can be expressed as

$e_1(x_k,y_k)=\mathrm{rect}\left(\frac{x_k}{l_x}\right)\left(\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="A200910045638E00141.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}(n-1)\mathrm{k\&Delta;}{\mathrm{\&theta;}}_y{y}_k\right)\mathrm{rect}\left(\frac{y_k}{l_y}\right)\right),$

Wherein: n is the refractive index of wedge glass, Δ θ _yBe the basic drift angle of unit rectangular optical wedge, λ is an optical maser wavelength.The divergence directivity function of this launching site strong production emission light beam is

${\mathrm{\&Theta;}}_t({\mathrm{\&theta;}}_{x,k},{\mathrm{\&theta;}}_{y,k})=\sin c\left(\frac{l_x}{\mathrm{\&lambda;}}{\mathrm{\&theta;}}_{x,k}\right)(\sin c\left(\frac{l_y}{\mathrm{\&lambda;}}{\mathrm{\&theta;}}_{y,k}\right)*\mathrm{\&delta;}({\mathrm{\&theta;}}_{y,k}-(n-1)\mathrm{k\&Delta;}{\mathrm{\&theta;}}_y)).$

Wherein: θ _{X, k}And θ _{Y, k}Be respectively k local coordinate system x _kDirection and y _kDeflection on the direction, ^*The expression convolution integral.

Telescope can be summarized as follows as the function that receives optical antenna:

Telescope when receiving optical antenna at the receiving aperture function of k unit rectangular optical wedge of rectangular optical wedge array 1 is

$p(x_k,y_k)=\mathrm{rect}\left(\frac{x_k}{l_x}\right)\left(\exp \left(\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="A200910045638E00141.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}(n-1)\mathrm{k\&Delta;}{\mathrm{\&theta;}}_y{y}_k\right)\mathrm{rect}\left(\frac{y_k}{l_y}\right)\right),$

This aperture function produces optical heterodyne receiving directivity directivity function

${\mathrm{\&Theta;}}_r({\mathrm{\&theta;}}_{x,k},{\mathrm{\&theta;}}_{y,k})=\sin c\left(\frac{l_x}{\mathrm{\&lambda;}}{\mathrm{\&theta;}}_{x,k}\right)(\sin c\left(\frac{l_y}{\mathrm{\&lambda;}}{\mathrm{\&theta;}}_{y,k}\right)*\mathrm{\&delta;}({\mathrm{\&theta;}}_{y,k}-(n-1)\mathrm{k\&Delta;}{\mathrm{\&theta;}}_y)).$

Definition: the optics toes be the acting in conjunction scope of launch spot and heterodyne capture area on target face, thus telescope simultaneously the comprehensive directivity function of rectangular optical wedge aperture, k the unit generation optics toes when transmitting and receiving antenna be

$\mathrm{\&Theta;}({\mathrm{\&theta;}}_{x,k},{\mathrm{\&theta;}}_{y,k})={\mathrm{\&Theta;}}_k({\mathrm{\&theta;}}_{x,k},{\mathrm{\&theta;}}_{y,k}){\mathrm{\&Theta;}}_r({\mathrm{\&theta;}}_{x,k},{\mathrm{\&theta;}}_{y,k})$

$={\left[\sin c\left(\frac{l_x}{\mathrm{\&lambda;}}{\mathrm{\&theta;}}_{x,k}\right)(\sin c\left(\frac{l_y}{\mathrm{\&lambda;}}{\mathrm{\&theta;}}_{y,k}\right)*\mathrm{\&delta;}({\mathrm{\&theta;}}_{y,k}-(n-1)k{\mathrm{\&Delta;\&theta;}}_y))\right]}^2$

As seen directivity function is centered close to (θ _{X, k}(0)=0, θ _{Y, k}(0)=(n-1) k Δ θ _y), directivity function exists in the position of the first zero of x direction ${\mathrm{\&theta;}}_{x,k}=\&PlusMinus;\frac{\mathrm{\&lambda;}}{l_x},$ The directivity width that is the x direction is:

${\mathrm{\&delta;\&theta;}}_x=\frac{2\mathrm{\&lambda;}}{l_x},$

Directivity function exists in the position of the first zero of y direction ${\mathrm{\&theta;}}_{y,k}=\&PlusMinus;\frac{\mathrm{\&lambda;}}{l_x}+(n-1)k{\mathrm{\&Delta;\&theta;}}_y,$ The directivity width that is the y direction is:

${\mathrm{\&delta;\&theta;}}_y=\frac{2\mathrm{\&lambda;}}{l_y}.$

Global coordinate system on the target face can be with (α β) expresses, and α is parallel to x, and β is parallel to y, and the center is on the z axle.The local coordinate system of optics toes on target face of k unit rectangular optical wedge generation is set at (α _k, β _k), satisfy coordinate relation (α _k=x, β _k=β-k (n-1) Δ θ _yZ),

Therefore its true origin is at (α=0, β=k (n-1) Δ θ _yZ).α as can be known _kDirection apart from width be

${\mathrm{\&delta;\&alpha;}}_k=\frac{2\mathrm{\&lambda;z}}{l_x}.$

β _kDirection apart from width be

${\mathrm{\&delta;\&beta;}}_k=\frac{2\mathrm{\&lambda;z}}{l_y},$

Therefore, the width of individual unit rectangular optical wedge directivity function ratio is

$\frac{{\mathrm{\&delta;\&theta;}}_y}{{\mathrm{\&delta;\&theta;}}_x}=\frac{{\mathrm{\&delta;\&beta;}}_k}{{\mathrm{\&delta;\&alpha;}}_k}=S_1.$

Be spaced apart (n-1) Δ θ at the aperture of two unit rectangular optical wedges of y direction toes directivity function _y, each single directivity function is combined in the y direction, form overlapping lengthening scanning band.If the overlap factor of single function is P (P≤1), then requirement

$\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="A200910045638E00141.png"\; state="\{\{state\}\}">P</figure-callout>}\frac{2\mathrm{\&lambda;}}{l_y}=(n-1){\mathrm{\&Delta;\&theta;}}_y,$

Perhaps the basic drift angle of unit rectangular optical wedge is:

${\mathrm{\&Delta;\&theta;}}_y=\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="A200910045638E00141.png"\; state="\{\{state\}\}">P</figure-callout>}\frac{2\mathrm{\&lambda;}}{(n-1)l_y}.$

At this moment the total directivity width Σ θ of the y direction that telescope produced that forms by 2K+1 unit rectangular optical wedge _yFor

Σθ _y＝((K-1)P+1)δθ _y，

Therefore the directivity width ratio of the telescopical directivity function of being made up of 2K+1 unit rectangular optical wedge is

S _K＝((K-1)P+1)S ₁°

Can convert on the target face equally and express, the α direction apart from width be

$\mathrm{\&delta;\&alpha;}=\frac{2\mathrm{\&lambda;z}}{l_x},$

The overlap distance width of β direction is

$\mathrm{\&Delta;\&beta;}=((K-1)P+1)\frac{2\mathrm{\&lambda;z}}{l_y}.$

The rectangular optical wedge array 1 of present embodiment is by 2K+1 (K=0, ± 1, ± 2, ± 3, ± K) individual unit rectangular optical wedge constitutes, with the dull and stereotyped wedge of K=0 is that benchmark divides up and down the series arrangement by K, K upwards〉1 positive dirction increases the wedge angle successively, K＜1 increases the arrangement of wedge angle in the other direction successively downwards, in fact on the contrary by K upwards〉the 1 positive dirction wedge angle of successively decreasing successively, downwards K＜1 wedge angle of successively decreasing is successively in the other direction arranged, even unit rectangular optical wedge mirror can be not according to the arbitrary arrangement of the order of k on the aperture, experimental analysis shows that the technique effect in the far field is the same.

Be the design of a specific embodiment below:

It is 500km that synthetic aperture laser imaging radar requires imaging viewing distance Z, and wavelength 1.55um requires resolution diameter δ d less than 100mm, scan stripes bandwidth 140m, and the vertically hung scroll width compares greater than 10 with resolution ³Adopt the mode of rectangular optical wedge array telescope while, by resolution requirement as optical heterodyne receiving antenna and plane wave emitting antenna $\mathrm{\&delta;d}=\frac{D}{N}$ N=2 so l are got in single rectangular aperture design _x=200mm, and according to rectangular aperture diffraction theorem α direction $\mathrm{\&delta;\&alpha;}=\frac{2\mathrm{\&lambda;z}}{l_x}$ Object plane illumination width is 7.75m.Get l _y=100mm is according to rectangular aperture diffraction ${\mathrm{\&delta;\&beta;}}_k=\frac{2\mathrm{\&lambda;z}}{l_y}$ Obtaining single hole illuminated scan strip width is 15.5m.Adopt aperture number K=11 and overlap factor P=0.8, then overlap distance width $\mathrm{\&Delta;\&beta;}=((K-1)P+1)\frac{2\mathrm{\&lambda;z}}{l_y}$ Final is 139.5m, at this moment requires the basic drift angle of wedge ${\mathrm{\&Delta;\&theta;}}_y=\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="A200910045638E00141.png"\; state="\{\{state\}\}">P</figure-callout>}\frac{2\mathrm{\&lambda;}}{(n-1)l_y}$ Be Δ θ _y=12.4 μ rad.

Claims (10)

1, a kind of rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar, it is characterized in that: the formation of described rectangular optical wedge array telescope comprises rectangular optical wedge array (1), object lens (2), eyepiece (3), spectroscope (4), rectangular aperture photodetector array (5), rectangular aperture generating laser array (6) and catoptron (7), described rectangular optical wedge array (1), object lens (2), eyepiece (3), spectroscope (4), rectangular aperture generating laser array (6) in turn is positioned on the light path, described rectangular optical wedge array (1) is positioned at the front focal plane of described object lens (2), described rectangular aperture photodetector array (5) is positioned at the back focal plane of described eyepiece (3), described rectangular aperture generating laser array (6) is positioned at the back focal plane of described eyepiece (3), described rectangular aperture photodetector array (5) and described catoptron (7) lay respectively on the reflected light path on two sides of described spectroscope (4), and the focal length of described object lens (2) is f ₁, the focal length of described eyepiece (3) is f ₂, the distance between described object lens (2) and the described eyepiece (3) is f ₁+ f ₂, this telescopical enlargement factor is $M=\frac{f_1}{f_2},$ Described spectroscope (4) is to carrying out the beam splitting combination from described rectangular aperture generating laser array (6) or from the light beam of object lens (2) and the light beam that enters described rectangular aperture photodetector array (5).

2, the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar according to claim 1, when it is characterized in that described rectangular optical wedge array telescope as the reception optical antenna, described rectangular optical wedge array (1) and object lens (2) are in the face of target, described rectangular optical wedge array (1) is the receiving telescope entrance pupil, described spectroscope (4) reflexes to described rectangular aperture photodetector array (5) to echo beam, and each unit rectangular optical wedge on the described rectangular optical wedge array (1) and the corresponding one by one imaging of unit rectangular detector on the described rectangular aperture photodetector array (5): the length of side of each unit rectangular optical wedge in the described rectangular optical wedge array (1) is respectively l _x, l _y, the cycle between the unit rectangular optical wedge is L _y, L satisfies condition _y〉=l _y, the yardstick of the unit rectangular detector on the described rectangular aperture photodetector array (5) is l _{X, r}, l _{Y, r}, satisfy $\frac{l_x}{l_{x,r}}=\frac{l_y}{l_{y,r}}=M.$

3, the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar according to claim 1, when it is characterized in that described rectangular optical wedge array telescope as the transmitting optics antenna, described rectangular aperture generating laser array (6) is gone out Laser emission by described rectangular optical wedge array (1), and the unit rectangular shaped light source on the described rectangular aperture generating laser array (6) goes up the corresponding one by one imaging of each unit rectangular optical wedge with described rectangular optical wedge array (1): the length of side of each unit rectangular optical wedge in the described rectangular optical wedge array (1) is respectively l _x, l _y, the cycle between the unit rectangular optical wedge is L _y, L satisfies condition _y〉=l _y, the yardstick of the unit rectangular shaped light source on the described rectangular aperture generating laser array (6) is l _{X, t}, l _{Y, t}, satisfy $\frac{l_x}{l_{x,t}}=\frac{l_y}{l_{y,t}}=M;$ Described spectroscope (4) reflexes to described catoptron (7) to the part light intensity of described rectangular aperture generating laser array (6), return again and arrive described rectangular aperture photodetector array (5) by described spectroscope (4), as the local oscillation array of source that optical heterodyne receives, each unit rectangular shaped light source of at this moment described rectangular aperture generating laser array (6) is corresponding one by one with the unit rectangular detector on the described rectangular aperture photodetector array (5): the yardstick l of the unit rectangular shaped light source on the described rectangular aperture generating laser array (6) _{X, t}, l _{Y, t}Respectively with described rectangular aperture photodetector array (5) on the yardstick l of unit rectangular detector _{X, r}, l _{Y, r}Equate.

4, the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar according to claim 1, it is characterized in that described rectangular optical wedge array (1) is made of 2K+1 unit rectangular optical wedge, wherein K=0, ± 1, ± 2, ± 3 ... ± K, the unit rectangular optical wedge of K=0 is dull and stereotyped wedge, the drift angle of K module unit rectangular optical wedge is K a times of basic drift angle, and the length of side of described unit rectangular optical wedge is respectively l _x, l _y, the cycle between the unit rectangular optical wedge is L _y, basic drift angle is: $\mathrm{\&Delta;}{\mathrm{\&theta;}}_y=P\frac{2\mathrm{\&lambda;}}{(n-1)l_y},$ Described l _xBy object plane illumination width $\mathrm{\&delta;\&alpha;}=\frac{2\mathrm{\&lambda;z}}{l_x}$ Decision, l _yBy the scan stripes bandwidth ${\mathrm{\&delta;\&beta;}}_k=\frac{2\mathrm{\&lambda;z}}{l_y}$ Decision, and scan stripes bandwidth ${\mathrm{\&delta;\&beta;}}_k=\frac{2\mathrm{\&lambda;z}}{l_y}$ With the resolution diameter $\mathrm{\&delta;d}=\frac{D}{N}$ The span of ratio be 10 ²～10 ³, the overlap distance width of object plane illumination is: $\mathrm{\&Delta;\&beta;}=((K-1)P+1)\frac{2\mathrm{\&lambda;z}}{l_y},$ In the formula: D is the telescopical diameter of the present invention, and N expresses the equivalent radius-of-curvature f of final orientation to phase place quadratic term course _FtAnd the constant that concerns between the target range z, P is an overlap factor, and K is an aperture number, and λ is a wavelength, and n is the refractive index of glass rectangular optical wedge, the unit rectangular optical wedge of described rectangular optical wedge array (1) puts in order arbitrarily.

5, the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar according to claim 4, it is characterized in that described rectangular optical wedge array (1) by K=0, ± 1, ± 2, ± 3 ... ,+(K-2) ,+(K-1) ,+the asymmetric a plurality of unit rectangular optical wedge of k constitutes.

6, according to the rectangular optical wedge array telescope antenna of claim 4 or 5 described synthetic aperture laser imaging radars, it is that dull and stereotyped wedge with K=0 is a benchmark that the unit rectangular optical wedge that it is characterized in that described rectangular optical wedge array (1) puts in order, divide and press the arrangement of K incremental order up and down, K upwards〉1 positive dirction increases the wedge angle successively, K＜1 increases the arrangement of wedge angle in the other direction successively downwards, or on the contrary by the K series arrangement of successively decreasing, K upwards〉the 1 positive dirction wedge angle of successively decreasing successively, K＜1 wedge angle of successively decreasing is successively in the other direction arranged downwards.

7, the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar according to claim 1, it is characterized in that described rectangular optical wedge array (1) is placed directly in described object lens front, but simultaneously place field lens on described object lens back focal plane, compensation is owing to described rectangular optical wedge array (1) leaves the additive phase quadratic term that the distance of the front focal plane of described object lens produces.

8, the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar according to claim 1, the xsect that it is characterized in that the unit rectangular optical wedge of described rectangular optical wedge array (1) are the right-angle triangle with chamfering, trapezoidal or equilateral triangle.

9, the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar according to claim 1, it is characterized in that each unit rectangular shaped light source of described rectangular aperture generating laser array (6) is the coherent array laser light source, or incoherent array laser light source.

10, the rectangular optical wedge array telescope antenna of synthetic aperture laser imaging radar according to claim 1, it is characterized in that each unit rectangular shaped light source emitted laser of described rectangular aperture generating laser array (6) is a plane wave, or Elliptical Gaussian Beam.

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