CN101179156A - Optimum setting angle based large-scale antenna reflecting plane gravity pre-regulation method - Google Patents

Abstract

The invention discloses a method for presetting the gravity of a reflector of a large antenna; according to law the Hooke and the superposition principle of vectors and on the basis of the structural mechanics analysis for the antenna, the method establishes the functional relation about the gravity deformation on antenna reflector nodes and the elevation so as to calculate the MSE (mean square error) of the reflector deformation of an arbitrary elevation relative to the optimally-matched paraboloid; aiming at the requirement for the antenna condition by users, the optimized mathematical model is established and an adjustment angle optimizing the antenna performance is solved; the gravity deformation figured out at the optimal adjustment angle is used as a preset valve for adjusting the elevation of the antenna; the axial height of an adjustment point on the antenna reflector is observed by an optical the theodolite so as to determine the posture of each panel on the whole reflector with the adjustment point configured to the position of the preset value. The invention has the advantages of evidently increasing the antenna reflector precision and the whole working performance, and can be used for the installation and adjustment for large antenna reflector.

Description

Adjust the large-scale antenna reflecting plane gravity preset method at angle based on the best

Technical field

The invention belongs to antenna technical field, specifically is a kind of large-scale antenna reflecting plane gravity preset method based on the best adjustment angle, is used in reference to the installation and the adjustment of lead antenna reflecting surface.

Background technology

The surface accuracy of antenna reflective face is to weigh the important technology performance index of estimating antenna quality, and it not only directly influences the aperture efficiency of antenna, thereby determines the minimal wave length that this antenna can be worked; Also influence the main lobe width and the secondary lobe structure of antenna pattern.By antenna reflective face is measured, determine its surface accuracy, can extrapolate its influence by surface accuracy to antenna electric performance.The surface accuracy of reflecting surface requires relevant with operating frequency, and operating frequency is high more, and just tight more to the requirement of surface accuracy, generally requiring surface accuracy is 1/16～1/32 of operation wavelength.

Large-scale antenna reflecting plane usually by tens in addition hundreds of piece Reflector Panel assembled, for obtaining reflecting surface surface accuracy preferably, the installation of each piece panel and adjustment just seem extremely important, its principle is to make antenna reflective face have the highest surface accuracy at place, the work elevation angle as far as possible, could satisfy the index request of electric property like this.Should carry out the installation and the adjustment of aerial panel at the place, the work elevation angle of antenna in theory, yet this situation is difficult for implementing in the engineering reality, and staff's coefficient of safety is low, special especially true when the antenna bore is very big, so should be chosen in the antenna attitude of looking up to heaven and carry out the installation and the adjustment of reflecting surface.In addition, some antenna is complete movable, its work elevation angle is a section, if theoretical position is adjusted in the Reflector Panel installation at a certain work elevation angle, when the same day, line was operated in other work elevation angle, because making again, the change of action of gravity direction cause antenna surface precise decreasing so that electrical property to reduce in Reflector Panel deviation theory position.

At present, the installation adjusting method of the most frequently used at home and abroad large-scale antenna reflecting plane has following several:

(1) installs and method of adjustment with the panel of micrometer instrument and steel hand tape combination.Utilize differential seat angle and radial dimension to obtain to adjust the axial error at some place, it is adjusted as adjustment amount.This method also is adjustment to be installed looking up to heaven, but just adjusts to the theoretical position when looking up to heaven, and when antenna forwarded the work elevation angle to, reflecting surface can produce gravity deformation again.As at A.Greve, D.Morris, L.E.B.Johansson.Precision of Radio Reflector SurfacesAdjusted from Theodolite-tape Measurements.IEE Proc-Microwave AntennasPropag., VOL.141, NO.1, the method that is adopted among the February 1994 is exactly this installation adjusting method.

(2) employing refers to the gentle comprehensive installation adjusting method of looking up to heaven, and promptly refers to install at ordinary times a part of antenna-reflected panel at antenna, and rotary antenna is installed and adjusted rest parts to the attitude of looking up to heaven then.This method is reported in " electric mechanical engineering " the 6th phase in 1999 " the crooked Kind of Shaped Paraboloid Antennas structure of large-scale list is installed and method of measurement " (Ling Jianping work) document to some extent.

(3) select to look up to heaven and refer to that flat intermediateness is that the elevation angle is 45 to calculate the preset amount of reflecting surface when spending.This kind installation adjusting method is reported in " astronomical research and technology " the 4th phase in 2006 " debugging of 40 aerial panels and precision analysis " (Jin Wang, Wang Min, work such as Zhang Juyong) document to some extent.

Adopt said method, aerial panel is installed and is adjusted at the attitude of looking up to heaven and carries out, and the assembly crewman will carry out every panel adjustment repeatedly, till the precision with respect to theoretical reflecting surface meets the requirements by rule of thumb according to measured data.Because the work elevation angle of antenna reality can not be entirely in the attitude of looking up to heaven, when being operated in the non-reflecting surface of adjusting during attitude of looking up to heaven, it can depart from original shape because of gravity deformation, cause the antenna electric performance variation.Urgent day by day along with to antenna heavy caliber and high-precision requirement, gravity deformation is to cause antenna reflective face to depart from one of most important factor of ideal form, the problem that the antenna-reflected surface accuracy is adjusted also can be more outstanding.

The content of invention

The objective of the invention is to avoid above-mentioned the deficiencies in the prior art, a kind of large-scale antenna reflecting plane gravity preset method based on the best adjustment angle is provided, instruct the installation and the adjustment of aerial panel, to improve antenna-reflected surface accuracy and integral working.

The technical scheme that realizes the object of the invention is, based on the antenna structure mechanical analysis, according to the functional relation of antenna reflecting plane gravity distortion with the elevation angle, at the requirement of user to the antenna operating mode, by optimizing the adjustment angle of determining whole antenna system performance the best, the selection attitude of looking up to heaven is carried out antenna and is installed and adjust, and calculating optimum is adjusted the gravity deformation at place, angle and calculated look up to heaven preset value when adjusting of antenna, and detailed process is as follows:

(1) antenna structure is carried out mechanical analysis, promptly the functional relation of setting up the antenna reflective face node gravity deformation and the elevation angle according to Hooke's law and vector superposed principle is:

δ(α)＝δ ₀cosα+δ ₉₀sinα

In the formula, δ (α) is the displacement because of gravity deformation deviation theory position when antenna elevation angle α of reflecting surface node,

δ ₀Being the reflecting surface node refers at ordinary times displacement because of gravity deformation deviation theory position at antenna,

δ ₉₀It is the displacement because of gravity deformation deviation theory position when antenna is looked up to heaven of reflecting surface node;

(2) according to the formula of step (1) gained, calculating elevation angle after the elevation angle gamma place adjusts reflecting surface is that α place distorted reflector is with respect to the identical paraboloidal mean square error of the best:

${\mathrm{\σ}}_{\mathrm{\α},\mathrm{\γ}}^2={\mathrm{\σ}}_0^2{(\cos \mathrm{\α}-\cos \mathrm{\γ})}^2+{\mathrm{\σ}}_{90}^2{(\sin \mathrm{\α}-\sin \mathrm{\γ})}^2$

In the formula, σ ₀Be that antenna is referring to reflecting surface node mean square of error root at ordinary times,

σ ₉₀It is antenna reflecting surface node mean square of error root when looking up to heaven;

(3) set up the adjustment angle γ that optimizes Mathematical Modeling and find the solution antenna performance the best, promptly

$\left\{\begin{array}{c}\mathrm{find\γ}\\ \mathrm{MinE}\left(\mathrm{\γ}\right)=\underset{a}{\mathrm{\Σ}}{W}_a[{\mathrm{\σ}}_0^2{(\cos \mathrm{\α}-\cos \mathrm{\γ})}^2+{\mathrm{\σ}}_{90}^2{(\sin \mathrm{\α}-\sin \mathrm{\γ})}^2]\\ s.t.\underset{\‾}{\mathrm{\γ}}\≤\mathrm{\γ}\≤\stackrel{\‾}{\mathrm{\γ}}\end{array}\right.$

In the formula, W _aBe the probability weight factor of section a, and ∑ W _a=1, γ is by being asked the elevation angle, and a is the section variable,

γWith

The lower limit and the upper limit of representing the antenna work elevation angle respectively;

(4) find the solution the attitude of looking up to heaven and carry out the preset value δ of the elevation angle when being γ _{γ y}:

δ _γy＝δ ₉₀-δ _γ

Wherein, δ _{γ y}Be displacement of the lines or angular displacement, δ _γNode distortion in surface during for elevation angle gamma;

(5) the Application Optics theodolite is observed the axial height Z value of antenna reflective face adjustment point, to determine the attitude of every panel in the entire emission face, will adjust and a little adjust to apart from theoretical position δ _{γ y}The place.

The present invention is owing to adopt the functional relation at the antenna reflecting plane gravity distortion and the elevation angle, and at the requirement of user to the antenna operating mode, by optimizing the adjustment angle of determining entire system performance the best, the selection attitude of looking up to heaven is carried out antenna and is installed and adjust, calculating optimum is adjusted the gravity deformation at place, angle and calculates antenna the preset value when looking up to heaven adjustment, the one, avoided antenna under the attitude of the different operating elevation angle gravity to the influence of reflector precision, the 2nd, realized under the guidance of theoretical method, reflector precision to the whole work of antenna system elevation angle section is considered as a whole, obtains best surface accuracy.

L-G simulation test proves, can improve reflector precision and integral working with method of the present invention.

Description of drawings

Fig. 1 is an antenna reflecting plane gravity preset flow chart of the present invention;

Fig. 2 is the distortion calculation flow chart of antenna reflective face of the present invention at the different elevations angle;

Fig. 3 is existing antenna structure gravitate schematic diagram;

Fig. 4 is the best parabolic schematic diagram that coincide of existing antenna;

Fig. 5 is the situation of change of antenna surface root-mean-square error of the present invention with the angle of pitch;

Fig. 6 is the phantom antenna structure of the present invention attitude gravity deformation figure that looks up to heaven;

Fig. 7 is that phantom antenna structure of the present invention refers to flat attitude gravity deformation figure;

Fig. 8 adopts the forward and backward antenna reflective face precision of gravity preset method of the present invention comparison diagram.

Embodiment

Followingly the present invention is described in further detail with reference to accompanying drawing.

For the antenna that is operated in fixed elevation, the selectively operating elevation angle is as the best angle of adjusting of antenna reflective face; For the movable antenna of omnidirectional, can be according to the characteristics of motion of tracking target, the elevation angle of will working is divided into several sections, obtain the probability that target occurs at each section, as weighted factor,, set up Mathematical Modeling optimization and find the solution the best angle of adjusting because the weighting half optical path difference quadratic sum minimum that the deadweight distortion causes is a target with each section.Antenna should be placed the best angle attitude of adjusting to carry out the installation adjustment of Reflector Panel in theory, but because large-scale reflector antenna structure is huge, when it tilts certain angle, the installation of panel will become with adjustment and be difficult for implementing, and therefore consider to carry out the installation and the adjustment of Reflector Panel in the attitude of looking up to heaven.On the reflecting surface of adjusting of looking up to heaven, because antenna tilt will the deviation theory position because of gravity deformation when the work elevation angle, so preset value that should be when looking up to heaven the consideration work elevation angle when adjusting.Calculate antenna reflective face when the work elevation angle gravity deformation and with it as preset value, the position the attitude of looking up to heaven is adjusted to preset with Reflector Panel adjustment point after, antenna will reach the reflector precision that makes whole antenna system performance the best when working.Before Reflector Panel was installed, the monolithic panel all need be measured through strict, satisfies the panel requirement on machining accuracy.Simultaneously, antenna reflective face back of the body frame also need be measured adjustment.On this basis, just can tentatively install, to guarantee that panel puts in place substantially each aerial panel.Just the panel circumferencial direction is generally adjusted by instruments such as theodolite are auxiliary in the process of assembling, lay unlikely distortion to guarantee panel, and panel is guaranteed by the installing hole of steel hand tape or panel itself generally radially.After aerial panel is just adorned, then need carry out further accurate the adjustment to every aerial panel position.Its basic skills is the axial height Z value that the Application Optics theodolite is observed reflecting surface adjustment point, to determine the attitude of every panel in the entire emission face, will adjust and a little adjust to apart from theoretical position δ _{γ y}The place.After using this method and adjusting reflecting surface, when the same day, the lineman stipulated the elevation angle or zone, the elevation angle, the influence of gravity had been overcome theoretically, and antenna system has best reflector precision at whole work section.Technical thought of the present invention is that antenna structure is carried out mechanical analysis, according to the functional relation at the distorted reflector and the elevation angle, determines best adjustment angle and calculate the gravity preset value that at customer requirements optimization the preset process as shown in Figure 1.

With reference to Fig. 1, concrete preset process of the present invention is as follows:

The first step, for the antenna structure of small deformation linear elasticity system, as shown in Figure 3, by Hooke's law get reflecting surface node distortion with from the wired sexual intercourse of heavy load:

{δ}＝[K] ^-1·{P} (1)

In the formula, P is a gravitational load; P _y=Pcos α is that gravity is along the axial component of y; P _z=Psin α gravity is along the axial component of z; α is antenna axis and horizontal plane angle, and K is the stiffness matrix of antenna structure.

In second step,, the gravity deformation of antenna reflective face under any angle of elevation alpha is decomposed at power P according to vector superposed principle _yWith power P _zThe effect stack of distortion down respectively:

δ(α)＝δ _y(α)+δ _z(α)＝δ ₀cosα+δ ₉₀sinα (2)

In the formula, δ (α) is the displacement of the gravity deformation deviation theory face of reflecting surface node when antenna elevation angle α,

δ ₀Being the reflecting surface node refers to the displacement of gravity deformation deviation theory face at ordinary times at antenna,

δ ₉₀Be the displacement of the gravity deformation deviation theory face of reflecting surface node when antenna is looked up to heaven,

These parameters can obtain by structure analysis software calculating or accurate measurement.

In the 3rd step,, calculate the mean square error of antenna reflective face according to the following procedure at the different elevations angle with reference to Fig. 2:

1. calculate i of reflecting surface according to formula (2) and be out of shape node with respect to the paraboloidal deviation of theory:

δ _i(α)＝δ _0icosα+δ _90isinα＝c _icos(α+ω _i) (3)

In the formula, $c_i=\sqrt{{\mathrm{\δ}}_{0i}^2+{\mathrm{\δ}}_{90i}^3},$ ω _i＝arctan(δ _90i/δ _0i)。

δ _0iBeing the antenna surface node refers to the displacement of gravity deformation deviation theory face at ordinary times at antenna,

δ _90iIt is the displacement of the gravity deformation deviation theory face of antenna surface node when antenna is looked up to heaven.

2. construct the conditional equation group of least square method according to the axial deviation of distorted reflector node:

Be abbreviated as:

[C]{H}＝{D} (5)

And following formula conditional equation group turned to the normal equation group:

[C] ^T[C]{H}＝[C] ^T{D} (6)

Find the solution this system of linear equations, can obtain the best paraboloidal identical parameter of coincideing:

H＝([C] ^T[C]) ^-1[C] ^T{D}＝{u _A，v _A，w _A， _x， _y，h} (7)

In the formula, x _i, y _i, z _iBe respectively three coordinate components of i distortion of reflecting surface node,

F is theoretical paraboloidal focal length,

u _A, v _A, w _ABe respectively best identical parabolic along x, y, three translation of axes amounts of z,

 _x,  _yBe the best parabolic rotation amount that coincide around x axle and y axle,

H is the best variable quantity of parabolic focal length with respect to theoretical focal length that coincide.

3. calculating optimum coincide node on the parabola with respect to the paraboloidal deviation of theory:

δ _bi(α)＝C _iH＝d _icos(α+θ _i) (8)

In the formula, $d_i=\sqrt{{\left(\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{B}_{\mathrm{ij}}{\mathrm{\δ}}_{0j}\right)}^2+{\left(\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{B}_{\mathrm{ij}}{\mathrm{\δ}}_{90j}\right)}^2};$ ${\mathrm{\θ}}_i=\arctan (\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{B}_{\mathrm{ij}}{\mathrm{\δ}}_{90j}/\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{B}_{\mathrm{ij}}{\mathrm{\δ}}_{0j});$

B _i=C _i([C] ^T[C]) ^-1[C] ^TB _IjBe vectorial B _iJ element.

4. with reference to Fig. 4, calculate the distorted reflector node with respect to the identical paraboloidal mean square error of the best:

${\mathrm{\&alpha;}}_{\mathrm{\&alpha;}}^2=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{({\mathrm{\&delta;}}_i-{\mathrm{\&delta;}}_{\mathrm{bi}})}^2={\mathrm{\&sigma;}}_0^2{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="S200710188489XE00011.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&alpha;}+{\mathrm{\&sigma;}}_{90}^2{\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="S200710188489XE00011.png"\; state="\{\{state\}\}">sin</figure-callout>}}^2\mathrm{\&alpha;}---\left(9\right)$

In the formula, σ ₀Be that antenna is referring to reflecting surface node mean square of error root at ordinary times,

σ ₉₀It is antenna reflecting surface node mean square of error root when looking up to heaven.

5. at the elevation angle gamma place reflecting surface is adjusted, each surperficial node is δ with respect to the identical paraboloidal adjustment amount of the best _i(γ)-δ _Bi(γ), the root-mean-square error when this just is equivalent to deduct the elevation angle and is γ, as shown in Figure 5.After the elevation angle gamma place adjusted reflecting surface, the elevation angle was that the root-mean-square error of α place distorted reflector is:

${\mathrm{\&sigma;}}_{\mathrm{\&alpha;},\mathrm{\&gamma;}}^2={\mathrm{\&sigma;}}_0^2{(\cos \mathrm{\&alpha;}-\cos \mathrm{\&gamma;})}^2+{\mathrm{\&sigma;}}_{90}^2{(\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;})}^2---\left(10\right)$

In the 4th step,, determine the adjustment angle γ of entire system performance the best according to the requirement of user to the antenna operating mode.

For the antenna that often is in a certain work elevation angle, can select it to point to the angle for the best angle γ of adjustment, just belong to this class as synchronous ground satellite station antenna; For the movable antenna of omnidirectional, can be according to the characteristics of motion of tracking target, the elevation angle of will working is divided into several sections, obtain the probability that target occurs at each section, as weighted factor, and express each section because the weighting half optical path difference quadratic sum that causes is out of shape in deadweight, the quadratic sum that so just can obtain the half optical path difference of antenna in the district of the whole work elevation angle is:

$E\left(\mathrm{\&gamma;}\right)=\underset{a}{\mathrm{\&Sigma;}}{W}_a[{\mathrm{\&sigma;}}_0^2{(\cos \mathrm{\&alpha;}-\cos \mathrm{\&gamma;})}^2+{\mathrm{\&sigma;}}_{90}^2{(\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;})}^2]---\left(11\right)$

Make antenna integral working the best in the work section will make above-mentioned (11) formula minimum, can set up in view of the above and seek the best Mathematical Modeling of adjusting the angle and be

$\left\{\begin{array}{c}\mathrm{find\&gamma;}\\ \mathrm{MinE}\left(\mathrm{\&gamma;}\right)=\underset{a}{\mathrm{\&Sigma;}}{W}_a[{\mathrm{\&sigma;}}_0^2{(\cos \mathrm{\&alpha;}-\cos \mathrm{\&gamma;})}^2+{\mathrm{\&sigma;}}_{90}^2{(\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;})}^2]\\ s.t.\underset{\&OverBar;}{\mathrm{\&gamma;}}\&le;\mathrm{\&gamma;}\&le;\stackrel{\&OverBar;}{\mathrm{\&gamma;}}\end{array}\right.---\left(12\right)$

The conventional numerical optimization of application is found the solution this (12) formula and just can be got best adjustment angle γ,

In the formula, W _aBe the probability weight factor of section a, and ∑ W _a=1; γ is by being asked the elevation angle; A is the section variable; γWith

The lower limit and the upper limit of representing the antenna work elevation angle respectively.

The 5th step, carry out the installation and the adjustment of aerial panel in the attitude of looking up to heaven, consider that preset should overcome gravity deformation δ when looking up to heaven ₉₀Influence, so the attitude of looking up to heaven is carried out the preset value δ of the elevation angle when being γ _{γ y}Should be:

δ _γy＝δ ₉₀-δ _γ (13)

In the formula, δ _{γ y}Be displacement of the lines or angular displacement, δ _γNode distortion in surface during for elevation angle gamma.

In the 6th step, the Application Optics theodolite is observed the axial height Z value of reflecting surface adjustment point, to determine the attitude of every panel in the entire emission face, will adjust and a little adjust to apart from theoretical position δ _{γ y}The place.

After the application said method was adjusted reflecting surface, when the same day, the lineman stipulated the elevation angle or zone, the elevation angle, the influence of gravity had been overcome theoretically, and antenna system has best reflector precision at whole work section.

Advantage of the present invention can further specify by following emulation:

Antenna reflecting plane gravity preset method of the present invention is carried out l-G simulation test on 12m bore parabolic antenna.This antenna reflective face by three circles totally 26 panels forms, work angle of elevation alpha between 10 °～80 °.

Fig. 6 and shown in Figure 7 be with the Ansys finite element software to antenna structure respectively in the result who refers to that the gentle attitude of looking up to heaven is carried out mechanical analysis, wherein 1. be undeformed antenna back frame structure, 2. be that gravitate is out of shape situation.Antenna is referring to the root-mean-square value σ of axial deviation and normal direction deviation at ordinary times ₀Be respectively 0.403mm and 0.617mm; And when looking up to heaven axially and the root-mean-square value σ of normal direction deviation ₉₀Be respectively 0.219 and 0.228.At given weighted factor W _aAfter, it is as shown in table 1 that by formula (12) the best of calculating is adjusted angle γ.

The best that table 1 adopts different error patterns to calculate is adjusted the angle

Error pattern	Refer to rms (mm) at ordinary times	Rms when looking up to heaven (mm)	The best angle (degree) of adjusting
				The axial error normal error	0.403 0.617	0.219 0.228	48.3 49.4

The antenna reflective face ratio of precision that shown in Figure 8 is adopts gravity preset method of the present invention and not preset.Curve adopts the obvious reflector precision height than not preset of gravity preset method of the present invention as can be seen from Fig. 8.In addition, when working the elevation angle below 50 degree, the reflector precision that adopts axial error preset to obtain is better than the result who adopts normal error preset slightly; And when above, adopt normal error preset effect better at 50 degree when the work elevation angle.

L-G simulation test shows, adopts the present invention to improve the reflector precision of antenna in whole work elevation angle district.

Claims (3)

1. adjust the large-scale antenna reflecting plane gravity preset method at angle based on the best for one kind, comprise following process:

(1) antenna structure is carried out mechanical analysis, promptly the functional relation of setting up the antenna reflective face node gravity deformation and the elevation angle according to Hooke's law and vector superposed principle is:

δ(α)＝δ ₀cosα+δ ₉₀sinα

In the formula, δ (α) is the displacement because of gravity deformation deviation theory position when antenna elevation angle α of reflecting surface node,

δ ₀Being the reflecting surface node refers at ordinary times displacement because of gravity deformation deviation theory position at antenna,

δ ₉₀It is the displacement because of gravity deformation deviation theory position when antenna is looked up to heaven of reflecting surface node;

(2) according to the formula of step (1) gained, calculating elevation angle after the elevation angle gamma place adjusts reflecting surface is that α place distorted reflector is with respect to the identical paraboloidal mean square error of the best:

${\mathrm{\&sigma;}}_{\mathrm{\&alpha;},\mathrm{\&gamma;}}^2={\mathrm{\&sigma;}}_0^2{(\cos \mathrm{\&alpha;}-\cos \mathrm{\&gamma;})}^2+{\mathrm{\&sigma;}}_{90}^2{(\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;})}^2$

In the formula, σ ₀Be that antenna is referring to reflecting surface node mean square of error root at ordinary times,

σ ₉₀It is antenna reflecting surface node mean square of error root when looking up to heaven;

(3) set up the adjustment angle γ that optimizes Mathematical Modeling and find the solution antenna overall performance the best, promptly

$\left\{\begin{array}{c}\mathrm{find\&gamma;}\\ \mathrm{MinE}\left(\mathrm{\&gamma;}\right)=\underset{a}{\mathrm{\&Sigma;}}{W}_a[{\mathrm{\&sigma;}}_0^2{(\cos \mathrm{\&alpha;}-\cos \mathrm{\&gamma;})}^2+{\mathrm{\&sigma;}}_{90}^2{(\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;})}^2]\\ s.t.\underset{\&OverBar;}{\mathrm{\&gamma;}}\&le;\mathrm{\&gamma;}\&le;\stackrel{\&OverBar;}{\mathrm{\&gamma;}}\end{array}\right.$

In the formula, W _aBe the probability weight factor of section a, and ∑ W _a=1, γ is the elevation angle of asking, and a is the section variable, γWith

The lower limit and the upper limit of representing the antenna work elevation angle respectively;

(4) find the solution the attitude of looking up to heaven and carry out the preset value δ of the elevation angle when being γ _{γ y}:

δ _γy＝δ ₉₀-δ _γ

In the formula, δ _{γ y}Be displacement of the lines or angular displacement, δ _γNode distortion in surface during for elevation angle gamma;

(5) the Application Optics theodolite is observed the axial height Z value of antenna reflective face adjustment point, to determine the attitude of every panel in the entire emission face, will adjust and a little adjust to apart from theoretical position δ _{γ y}The place.

2. preset method according to claim 1 is characterized in that step (2) carries out according to the following procedure:

1) calculate i of reflecting surface according to the formula of step (1) and be out of shape node with respect to the paraboloidal deviation of theory:

δ _i(α)＝δ _0icosα+δ _90isinα＝c _icos(α+ω _i)

In the formula, δ _0iAnd δ _90iBe respectively i distortion node deviation with respect to theoretical face when referring to gentle looking up to heaven,

$c_i=\sqrt{{\mathrm{\&delta;}}_{0i}^2+{\mathrm{\&delta;}}_{90i}^2},{\mathrm{\&omega;}}_i=\arctan ({\mathrm{\&delta;}}_{90i}/{\mathrm{\&delta;}}_{0i});$

2) according to the conditional equation group of the axial deviation of step 1) distorted reflector node structure least square method:

Be abbreviated as:

[C]{H}＝{D}

And following formula conditional equation group turned to the normal equation group:

[C] ^T[C]{H}＝[C] ^T{D}

Find the solution this system of linear equations, can obtain the best paraboloidal identical parameter of coincideing:

H＝([C] ^T[C]) ^-1[C] ^T{D}＝{u _A，v _A，w _A， _x， _y，h}

In the formula, x _i, y _i, z _iBe respectively three coordinate components of i distortion of reflecting surface node,

F is theoretical paraboloidal focal length,

u _A, v _A, w _ABe respectively best identical parabolic along x, y, three translation of axes amounts of z,

 _x,  _yBe the best parabolic rotation amount that coincide around x axle and y axle,

H is the best variable quantity of parabolic focal length with respect to theoretical focal length that coincide;

3) calculating optimum coincide node on the parabola with respect to the paraboloidal deviation of theory:

δ _bi(α)＝C _iH＝d _icos(α+θ _i)

In the formula, $d_i=\sqrt{{\left(\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{B}_{\mathrm{ij}}{\mathrm{\&delta;}}_{0j}\right)}^2+{\left(\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{B}_{\mathrm{ij}}{\mathrm{\&delta;}}_{90j}\right)}^2},$ ${\mathrm{\&theta;}}_i=\arctan (\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{B}_{\mathrm{ij}}{\mathrm{\&delta;}}_{90j}/\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{B}_{\mathrm{ij}}{\mathrm{\&delta;}}_{0j}),$

B _i=C _i([C] ^T[C]) ^-1[C] ^T, B _IjBe vectorial B _iJ element;

4) calculate the distorted reflector node with respect to the identical paraboloidal mean square error of the best:

${\mathrm{\&alpha;}}_{\mathrm{\&alpha;}}^2=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{({\mathrm{\&delta;}}_i\left(\mathrm{\&alpha;}\right)-{\mathrm{\&delta;}}_{\mathrm{bi}}\left(\mathrm{\&alpha;}\right))}^2={\mathrm{\&sigma;}}_0^2{\cos }^2\mathrm{\&alpha;}+{\mathrm{\&sigma;}}_{90}^2{\sin }^2\mathrm{\&alpha;}$

5) at the elevation angle gamma place of antenna reflecting surface is adjusted, each surperficial node is δ with respect to the identical paraboloidal adjustment amount of the best _i(γ)-δ _Bi(γ), obtaining the elevation angle is that α place distorted reflector is with respect to the identical paraboloidal mean square error of the best:

${\mathrm{\&sigma;}}_{\mathrm{\&alpha;},\mathrm{\&gamma;}}^2={\mathrm{\&sigma;}}_0^2{(\cos \mathrm{\&alpha;}-\cos \mathrm{\&gamma;})}^2+{\mathrm{\&sigma;}}_{90}^2{(\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;})}^2$

In the formula, σ ₀Be that antenna is referring to reflecting surface node mean square of error root at ordinary times,

σ ₉₀It is antenna reflecting surface node mean square of error root when looking up to heaven.

3. preset method according to claim 1 is characterized in that the adjustment angle γ that the described foundation of step (3) is optimized Mathematical Modeling and found the solution antenna overall performance the best, is according to the requirement of user to the antenna operating mode, is divided into two kinds of situations and carries out:

A for the fixed pose antenna that often is in a certain work elevation angle, selects it to point to the angle and is the best angle γ of adjustment;

B, the on-fixed attitude antenna for the change of the work elevation angle, carry out according to the following procedure:

B1, according to the characteristics of motion of tracking target, the elevation angle of will working is divided into several sections, obtains the probability that target occurs at each section, as weighted factor, and expresses each section because the deadweight distortion with respect to the identical paraboloidal weighted mean square error of the best is:

$E\left(\mathrm{\&gamma;}\right)=\underset{a}{\mathrm{\&Sigma;}}{W}_a[{\mathrm{\&sigma;}}_0^2{(\cos \mathrm{\&alpha;}-\cos \mathrm{\&gamma;})}^2+{\mathrm{\&sigma;}}_{90}^2{(\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;})}^2]$

In the formula, W _aBe the probability weight factor of section a, and ∑ W _a=1, γ is by being asked the elevation angle, and a is the section variable, γWith

The lower limit and the upper limit of representing the antenna work elevation angle respectively;

B2. the weighted mean square error formula in the whole work elevation angle district that is obtained by step B1 is set up and is sought the best Mathematical Modeling of adjusting the angle and be

$\left\{\begin{array}{c}\mathrm{find\&gamma;}\\ \mathrm{MinE}\left(\mathrm{\&gamma;}\right)=\underset{a}{\mathrm{\&Sigma;}}{W}_a[{\mathrm{\&sigma;}}_0^2{(\cos \mathrm{\&alpha;}-\cos \mathrm{\&gamma;})}^2+{\mathrm{\&sigma;}}_{90}^2{(\sin \mathrm{\&alpha;}-\sin \mathrm{\&gamma;})}^2]\\ s.t.\underset{\&OverBar;}{\mathrm{\&gamma;}}\&le;\mathrm{\&gamma;}\&le;\stackrel{\&OverBar;}{\mathrm{\&gamma;}}\end{array}\right.$

B3, the Mathematical Modeling of utilizing conventional numerical optimization that the best is adjusted the angle is found the solution, and obtains the adjustment angle γ of antenna overall performance the best.

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