CN103389493A - Multi-beam single-pulse angle measuring method based on beam selection method - Google Patents

Abstract

The invention provides a multi-beam single-pulse angle measuring method based on a beam selection method. The method mainly solves the problem that two-beam single-pulse angle measurement is small in airspace covering range and low in accuracy under the condition of the existing hardware system. The method includes the following detection steps: 1) forming M beams simultaneously in pitching dimensions with each beam 1-degree larger than the last one and dividing the covered airspace into M-1 angle measuring sections; 2) building a discrimination angle curve under the off-line condition according to the ideal antenna receiving signal amplitude difference and ratio; 3) selecting the optimum beam distance and the optimum beam according to each angle measuring section theta i, i+1; 4) determining the affiliated angle measuring section theta i, i+1 according to the target echo strength; 5) determining the optimum angle measuring beam combination in an off-line mode through the step 3) and calculating difference and ratio of radar target echo received by the beam combination. The point that the difference and ratio corresponds to in the discrimination angle curve corresponding to the beam combination is the target angle. The method is small in calculation amount and high in angle measuring accuracy due to the fact that angle measurement is conducted by optimally selecting the optimum beam distance and the optimum beam under the condition of multiple beams.

Description

Multi-beam monopulse angle-measuring method based on beam selection method

Technical field

The invention belongs to the Radar Technology field, relate to ball and carry the detection of radar to target, specifically a kind of monopulse of multi-beam based on beam selection method angle-measuring method, be used for ball and carry the angle detection of radar to the low latitude treetop level target.

Background technology

Repeatedly show under battle conditions, cruise missile has become the important weapon of remote precision strike, the survival and development to the early warning detection system have proposed serious challenge, and to the key of its defence, be exactly Detection And Tracking, but be subjected to the impact of many factors, ground radar cruise missile detectivity is limited, is difficult to meet operational need.

At present the detection method of cruise missile is mainly concentrated on the advanced detector that utilizes the high or airborne platform of radar frame and range detector carried out networking survey two large fields.It is a kind of integrated information system take captive balloon as platform, take radar as acquisition sensor that ball carries radar, supplementing of AWACS and home radar chain, by Texas tower is raise, overcome to a certain extent the impact of earth curvature, give full play to the radar own resources, make it have a detection range on cruise missile is surveyed far away, find the advantages such as target morning.Therefore, since entering the eighties in 20th century, along with the modern development of military technology, doctrine of tactics and conventional weapon, the important directions of radar as the development of cruise missile detection equipment carried to ball in many countries.It, with the advantage of the aspects such as exclusive economy, stealth, security, is widely used in the detection to the low latitude treetop level target.

Ball carries in the acquisition process of radar to low latitude treetop level target angle information, usually can meet the demands because of the narrower reason angular resolution of wave beam in azimuth dimension, and in the process that the angle of pitch is measured, because beam angle is wider, usually can't directly obtain the higher angle information of precision, therefore adopt the monopulse angle-measuring method.In addition, single-pulse track more accurately and not is subject to the impact such as electronic countermeasures means of AM interference and gain inversion etc., in sequence wave valve and conical scanning method, variable quantity in radar return can reduce tracking accuracy, just can not there is this problem and with monopulse, produce error signal, because individual pulse will the generated error signal.Monopulse tracking radar not only can but also can have been used phased array antenna with antenna reflector.Array antenna uses flexibly, but the T/R antenna module is subjected to the array element Effects of Density to make volume large, weight is large, cost is high, it carries in the Radar Technology application at modern ball is not also very ripe, and parabola antenna has simple in structure, and is lightweight, low cost and other advantages, adopt the parabola feed antenna therefore most of ball carries radar.General monopulse angle measurement technique only forms two wave beams in the measuring process of the angle of pitch, if only use two wave beam angle measurements in practical engineering application, its space area coverage is little, if being in outside area coverage, target can cause the serious consequence that target do not detected, on the other hand, even if within target is in the wave beam area coverage, but when away from the beam axis direction, arriving, target echo power is little, and angle measurement accuracy is not optimum.These drawbacks are restricting ball and are carrying the acquisition of radar to angle on target information, also have influence on actual angle measurement accuracy.At present, especially for the large ball of spatial domain area coverage, carry radar antenna urgent need high precision angle-measuring method supporting with it.

Summary of the invention

The object of the invention is to for existing two wave beam monopulse angle measurement technique spatial domain area coverages little, the deficiency that angle measurement accuracy is lower, for the large antenna hardware system of spatial domain area coverage, a kind of angle measurement accuracy is proposed higher, the monopulse of the multi-beam based on the beam selection method angle-measuring method that calculated amount is little.

The present invention is achieved in that

One, know-why

Traditional monopulse angle measurement technique is to produce two identical wave beam F in an angle plane ₁(θ) and F ₂(θ), two wave-packet portions are overlapping, two wave beams sue for peace with wave beam F _Σ(θ), subtract each other to obtain difference beam F _Δ(θ), do by comparer that ratio is differed from and compare

ε (θ) is called the mirror angular curve with the curve that elevation angle theta changes.When true echo signal arrives, release θ counter according to the value of ε (θ), the ultimate principle of monopulse angle measurement that Here it is.

The present invention utilizes many horn feeds parabola antenna to produce simultaneously M wave beam in elevation plane, supposes that the angle between adjacent two beam axis is 1 °, and the differential seat angle between any two beam axis is defined as the wave beam spacing, and the wave beam spacing is δ ₁=1 °, δ ₂=2 ° ... δ _M-1=(M-1) °.

Known while utilizing the monopulse angle measurement, its point of theory error

$\mathrm{\&Delta;\&theta;}=\frac{\sqrt{2}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="HSA00000921442300032.png,HSA00000921442300042.png"\; state="\{\{state\}\}">B</figure-callout>}}^2}{2.8\mathrm{\&delta;}\sqrt{{\mathrm{SNR}}_{\mathrm{\&Sigma;}}}}---\left(1\right)$

Wherein, δ is the wave beam spacing, SNR _∑For with passage signal to noise ratio (S/N ratio), θ _BFor half-power beam width.

Antenna is given, and half-power beam width is fixed, and by formula (1), knows that the point of theory error mainly is subject to wave beam spacing δ, and the passage signal to noise ratio snr _ΣThe impact of two factors.Suppose with channel receiving signal to be

y _Σ(t)＝s(t)S _ij(θ)+n(t) (2)

Wherein, s (t) is complex envelope, S _ijBe (θ) that i wave beam and j wave beam form and wave beam, the variance of noise n (i) is σ ²So, and the passage signal to noise ratio (S/N ratio)

Known by formula (1)

, for making angle error Δ θ minimum, can be summed up as the solution optimization problem

Suppose that noise power is certain, problem is further converted to

So far this optimization problem be converted into solve suitable wave beam spacing and and beam gain, make both long-pending maximum.

Select in the present invention different angle measurement beam combination, wave beam spacing δ _jChange, so above-mentioned optimization problem is converted into, solve j and k _jMake

1≤j≤M-1 wherein, 1≤k _j≤ M-j.Formula (1) is converted into

$\mathrm{\&Delta;\&theta;}=\frac{\sqrt{2}{\mathrm{\&theta;}}_{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="HSA00000921442300032.png,HSA00000921442300042.png"\; state="\{\{state\}\}">B</figure-callout>}}^2\mathrm{\&sigma;}}{2.8{\mathrm{\&delta;}}_{j}s\left(t\right)S_{k_j,k_j+j}\left(\mathrm{\&theta;}\right)}---\left(3\right)$

Therefore utilize the selected optimum wave beam spacing δ of an existing M wave beam _j, optimum and wave beam

Make angle error Δ θ minimum.

Two, technical scheme

According to above-mentioned principle, the monopulse of the multi-beam based on beam selection angle-measuring method of the present invention realizes including following steps:

Step 1 is utilized radar parabola feed antenna to form simultaneously M wave beam and it is covered spatial domain and is divided into M-1 angle measurement interval: the angle between two adjacent beams axles is as an angle measurement interval, and it is θ that M wave beam covers spatial domain division result _1,2, θ _2,3θ _{I, i+1}, 1≤i≤M-1 wherein, θ _{I, i+1}For the angle between the beam axis of the beam axis of wave beam i and wave beam i+1.

Step 2 receives signal amplitude difference according to ideal antenna under off-line case and ratio is set up the mirror angular curve: according to antenna receiving signal, every two wave beams are done and are obtained and wave beam, do difference and obtain difference beam, differ from the mirror angular curve that obtains its correspondence with ratio.

Step 3 is for the interval θ of each angle measurement _{I, i+1}Select optimum wave beam spacing to reach and wave beam: for the interval θ of each angle measurement _{I, i+1}Selected a kind of angle measurement wave beam spacing δ ₁, the gain that target arrives each and wave beam is different, by comparer determine under this wave beam spacing condition with the beam gain maximal value 1≤k wherein ₁≤ M-1; Selected another angle measurement wave beam spacing δ ₂, in like manner select under this wave beam spacing condition with the beam gain maximal value 1≤k wherein ₂≤ M-2, the rest may be inferred, and the long-pending descending sequence again of the wave beam spacing that these and beam gain maximal value is corresponding with it finally obtains maximal value, and corresponding two wave beams of this maximal value are optimum angle measurement beam combination.

Step 4 radar antenna receives signal in real time, according to the real goal echo strength, determines the interval θ of angle measurement that target belongs to _{I, i+1}: for M wave beam, M passage just arranged, all channel receiving signals are sorted according to the signal amplitude value is descending, corresponding two wave beams of its first two signal amplitude value, the folded angular regions of this two beam axis is the angular interval that target belongs to.

Step 5 detects angle on target: the optimum angle measurement beam combination of utilizing step 3 off-line to determine is carried out angle measurement to target, poor according to radar real-time target echo and the ratio, poor and than also referred to as with the mistake difference signal, its corresponding angle of search in mirror angular curve corresponding to this beam combination, this angle are the angle on target that utilizes the multi-beam monopulse angle-measuring method based on beam selection method to obtain.

Therefore, in order to cover larger spatial domain and to improve the measuring accuracy of the angle of pitch, the present invention adopts ball to carry many horn feeds of radar parabola antenna and forms M wave beam and come the luffing angle position of measurement target, and the spatial domain area coverage is about M °, and angle measurement accuracy reaches 0.1 °.

Three, the present invention compared with prior art has the following advantages:

1. under existing many horn feeds parabola antenna hardware system condition, the present invention takes full advantage of the wave beam spacing and reaches and two factors that affect angle measurement accuracy of passage signal to noise ratio (S/N ratio),, in the situation that the optimization of a plurality of wave beams is selected optimum wave beam spacing and with wave beam, carries out angle measurement, make the angle measurement effect be optimized.

2. calculated amount is little.The present invention is that the selection of only passing through wave beam under existing many horn feeds parabola antenna hardware system condition improves angle measurement accuracy, do not increase calculated amount, and the angle measurement beam combination is that off-line is determined, after determining when processing the real time radar signal process selected of repeated optimization again.

Description of drawings

Fig. 1 is process flow diagram of the present invention;

Fig. 2 is engineering schematic diagram of the present invention;

Fig. 3 is the present invention's analogous diagram while selecting 1 ° of wave beam spacing, and wherein Fig. 3 (a) is antenna radiation pattern, and Fig. 3 (b) is and wave beam, and Fig. 3 (c) is difference beam, and Fig. 3 (d) is the mirror angular curve;

Fig. 4 is the present invention's analogous diagram while selecting 2 ° of wave beam spacings, and wherein Fig. 4 (a) is antenna radiation pattern, and Fig. 4 (b) is and wave beam, and Fig. 4 (c) is difference beam, and Fig. 4 (d) is the mirror angular curve;

Fig. 5 is the present invention's analogous diagram while selecting 3 ° of wave beam spacings, and wherein Fig. 5 (a) is antenna radiation pattern, and Fig. 5 (b) is and wave beam, and Fig. 5 (c) is difference beam, and Fig. 5 (d) is the mirror angular curve;

Fig. 6 is the present invention's analogous diagram while selecting 4 ° of wave beam spacings, and wherein Fig. 6 (a) is antenna radiation pattern, and Fig. 6 (b) is and wave beam, and Fig. 6 (c) is difference beam, and Fig. 6 (d) is the mirror angular curve;

Fig. 7 is that the present invention works as signal from elevation angle Φ=-2 °～-1 °, two adjacent beams form with the wave beam signal to noise ratio (S/N ratio) be 25dB, the angle error curve map that adopts the different wave beam angle measurement of spacing and carry out 1000 Monte-Carlo experiments;

Fig. 8 is signal of the present invention from elevation angle Φ=-1 °～0 °, two adjacent beams form with the wave beam signal to noise ratio (S/N ratio) be 25dB, the angle error curve map that adopts the different wave beam angle measurement of spacing and carry out 1000 Monte-Carlo experiments;

Fig. 9 is signal of the present invention from elevation angle Φ=0 °～1 °, two adjacent beams form with the wave beam signal to noise ratio (S/N ratio) be 25dB, the angle error curve map that adopts the different wave beam angle measurement of spacing and carry out 1000 Monte-Carlo experiments;

Figure 10 is signal of the present invention from elevation angle Φ=1 °～2 °, two adjacent beams form with the wave beam signal to noise ratio (S/N ratio) be 25dB, the angle error curve map that adopts the different wave beam angle measurement of spacing and carry out 1000 Monte-Carlo experiments;

The beam selection criterion curve map that carries out angle measurement when Figure 11 is the present invention to target from elevation angle Φ=-2 °～2 °.

Embodiment

Below in conjunction with accompanying drawing, the present invention is elaborated

Embodiment 1

The present invention is a kind of monopulse of multi-beam based on beam selection method angle-measuring method, it is existing that to carry the angle-measuring method angle measurement accuracy of radar antenna for ball low, the present invention is directed to the large ball of spatial domain area coverage and carry radar antenna and proposed high precision angle-measuring method,, referring to Fig. 1, comprise the steps:

Step 1 is utilized radar parabola feed antenna to form simultaneously M wave beam and it is covered spatial domain and is divided into M-1 angle measurement interval: the angle between two adjacent beams axles is as an angle measurement interval, and it is θ that M wave beam covers spatial domain division result _1,2, θ _2,3θ _{I, j+1}, 1≤i≤M-1 wherein, θ _1,2For the folded angle of the beam axis of the beam axis of wave beam 1 and wave beam 2.M wave beam covered the division in spatial domain, comprise the steps:

(1a) feed of antenna is a plurality of loudspeaker, homeotropic alignment on the focal plane of parabolic reflector, and each loudspeaker are off-focal in succession, therefore form a partly overlapping M wave beam each other, 1 ° of adjacent two wave beam spacing on elevation plane;

(1b) will be from the echo signal between the adjacent beam axis of two-phase as an angle measurement interval, the division result is θ _1,2, θ _2,3θ _{I, i+1}, wherein 1≤i≤M-1, be divided into M-1 angle measurement interval, as shown in Figure 2 altogether.

Step 2 receives signal amplitude difference according to ideal antenna under off-line case and ratio is set up the mirror angular curve: according to antenna receiving signal, every two wave beams are done and are obtained and wave beam, do difference and obtain difference beam, differ from the mirror angular curve that obtains its correspondence with ratio.Angle that difference beam is combined with the ratio with wave beam is made curve, is the mirror angular curve.Receive signal amplitude difference according to ideal antenna and, than setting up the mirror angular curve, carry out as follows under off-line case:

(2a) according to ideal antenna, receive signal spatial domain scanned, every two wave beam additions must with wave beam F _Σ(θ), subtract each other to obtain difference beam F _Δ(θ), do that ratio is differed from and compare

Thereby set up the mirror angular curve;

(2b) every two adjacent beams are set up the mirror angular curve and can be obtained M-1 bar mirror angular curve, the wave beam combination of two that spacing is 2 ° can obtain M-2 bar mirror angular curve, the wave beam combination of two that spacing is 3 ° can obtain M-3 bar mirror angular curve, the rest may be inferred, the wave beam combination of two of spacing i ° can obtain M-i bar mirror angular curve, 1≤i≤M-1 wherein, mirror angular curve of the present invention is set up in desirable antenna receiving signal situation, and the angle information of target necessarily drops on the mirror angular curve.

Step 3 is for the interval θ of each angle measurement _{I, i+1}Select optimum wave beam spacing to reach and wave beam: for the interval θ of each angle measurement _{I, i+1}Selected a kind of angle measurement wave beam spacing δ ₁, the gain that target arrives each and wave beam is different, by comparer determine under this wave beam spacing condition with the beam gain maximal value

1≤k wherein ₁≤ M-1; Selected another angle measurement wave beam spacing δ ₂, in like manner select under this wave beam spacing condition with the beam gain maximal value

1≤k wherein ₂≤ M-2, the rest may be inferred, obtains altogether M-1 and beam gain maximal value, finally these and the beam gain maximal value wave beam spacing corresponding with it multiplied each other, the long-pending descending sequence that to multiply each other, in ranking results, corresponding two wave beams of maximal value are optimum angle measurement beam combination.

Step 4 radar antenna receives signal in real time, according to the real goal echo strength, determines the interval θ of angle measurement that target belongs to _{I, i+1}: each single channel of radar antenna receives signal in real time, for M wave beam, M passage just arranged, the present invention is to all channel receiving signals, sort according to the signal amplitude value is descending, corresponding two wave beams of its first two signal amplitude value, the folded angular regions of this two beam axis is the angular interval θ that target belongs to _{I, i+1}.

Step 5 detects angle on target: utilize step 3 off-line to determine optimum angle measurement beam combination, the radar real-time target echo that this beam combination is received calculates poor and ratio, utilize poor and than search for angle on target in mirror angular curve corresponding to this beam combination, this angle is the angle on target that utilization obtains based on the multi-beam monopulse angle-measuring method of beam selection method.

After optimum angle measurement beam combination was definite, the mirror angular curve of its correspondence was just definite, and it is poor that the radar real-time target echo that the optimal beam combination receives is done and done, then carry out the ratio computing, and ratio in mirror angular curve definite angle corresponding to target poor according to this.

The factor that affects monopulse angle measurement technique angle measurement accuracy has wave beam spacing δ, and the passage signal to noise ratio snr _∑, half-power beam width θ _B.Antenna is certain, θ _BJust determined, so the principal element that affects angle measurement accuracy is exactly δ and SNR _∑, as noise power one timing, SNR _∑, by with beam gain, determining, so affect the principal element of monopulse angle measurement technique angle measurement accuracy, be exactly only wave beam spacing δ and and beam gain.

Under existing many horn feeds parabola antenna hardware system condition, the present invention take full advantage of the wave beam spacing and and and two factors that affect angle measurement accuracy of beam gain, in the situation that the optimization of a plurality of wave beams selects optimum wave beam spacing to reach and wave beam, be that the long-pending maximum beam combination that wave beam spacing δ reaches and beam gain multiplies each other is carried out angle measurement, make the angle measurement effect be optimized.

Embodiment 2

Based on the multi-beam monopulse angle-measuring method of beam selection method with embodiment 1:

Step 1, utilize the parabola feed antenna to form simultaneously M wave beam and it is covered spatial domain and be divided into M-1 angle measurement interval:

The feed of antenna is a plurality of loudspeaker, homeotropic alignment on the focal plane of parabolic reflector, each loudspeaker are off-focal in succession, therefore form a partly overlapping M wave beam each other on elevation plane, 1 ° of adjacent two wave beam spacing, for angle measurement is convenient will be from the echo signal between the adjacent beam axis of two-phase as an angle measurement interval, this example is the target level distance R, the radar antenna height is that the radar antenna between the radar service area of H covers spatial domain and is divided into θ _1,2, θ _2,3θ _{I, i+1}, wherein 1≤i≤M-1, be total to M-1 angle measurement interval, as shown in Figure 2.

Step 2 receives signal amplitude difference and ratio foundation mirror angular curve according to ideal antenna under off-line case:

Receive signal according to ideal antenna spatial domain is scanned, obtain and wave beam F _Σ(θ), difference beam F _Δ(θ), do that ratio is differed from and compare

ε (θ) and θ set up the mirror angular curve.Every two adjacent beams are set up the mirror angular curve can obtain M-1 bar mirror angular curve, the wave beam combination of two that spacing is 2 ° can obtain M-2 bar mirror angular curve, the wave beam combination of two that spacing is 3 ° can obtain M-3 bar mirror angular curve, the rest may be inferred, and the wave beam combination of two of spacing i ° can obtain M-i bar mirror angular curve, wherein 1≤i≤M-1, trend such as Fig. 3 d of mirror angular curve, 4d, 5d, shown in 6d.

Step 3, for the interval θ of each angle measurement _{I, i+1}Select suitable wave beam spacing to reach and wave beam:

(3a) wave beam spacing δ ₁In the time of=1 °, obtaining with beam gain is S _1,2(θ), S _2,3(θ), S _3,4(θ) ... S _{M-1, M}(θ), its descending sequence is obtained maximal value

1≤k wherein ₁≤ M-1;

(3b) wave beam spacing δ ₂In the time of=2 °, obtaining with beam gain is S _1,3(θ), S _2,4(θ), S _3,5(θ) ... S _{M-2, M}(θ), its descending sequence is obtained maximal value

1≤k wherein ₂≤ M-2;

(3c) the rest may be inferred, wave beam spacing δ _i=i °, wherein during 1≤i≤M-1, obtaining with beam gain is S _{1, i}(θ), S _2,2+i(θ), S _3,3+i(θ) ... S _{M-i, M}(θ), its descending sequence is obtained maximal value 1≤k wherein _i≤ M-i;

(3d) right ${\mathrm{\&delta;}}_1\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="S\; k"\; filenames="HSA00000921442300032.png,HSA00000921442300051.png"\; state="\{\{state\}\}">S</figure-callout>}}_{k_{}}\left(\mathrm{\&theta;}\right),$ ${\mathrm{\&delta;}}_2\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="S\; k"\; filenames="HSA00000921442300032.png,HSA00000921442300042.png"\; state="\{\{state\}\}">S</figure-callout>}}_{k_{}}\left(\mathrm{\&theta;}\right)\&CenterDot;\&CenterDot;\&CenterDot;{\mathrm{\&delta;}}_i\&CenterDot;S_{k_i,k_i+i}\left(\mathrm{\&theta;}\right)$ Descending sequence, try to achieve its maximal value

1≤j≤M-1 wherein.δ _jBe the wave beam spacing that select,

Be angle measurement and the wave beam that select, thereby determine angle measurement beam combination and corresponding mirror angular curve.

Known by formula (3)

Maximum just means that angle error Δ θ is minimum.

Step 4, determine according to radar real goal echo strength the interval θ of angle measurement that target belongs to _{I, i+1}:

M wave beam obtains M and receives signal, according to the descending sequence of signal amplitude value, obtains y ₁(t) 〉=y ₂(t) 〉=... 〉=y _M(t), can determine that thus target is from y ₁(t) and y ₂(t) two corresponding wave beam p ₁(θ) and p ₂The angular interval θ that beam axis (θ) is folded _{I, i+1}.

Step 5, utilize step 3 off-line to determine optimum angle measurement beam combination, the radar real-time target echo that this beam combination is received calculates poor and ratio, utilize poor and than search for angle on target in mirror angular curve corresponding to this beam combination, this angle is the angle on target that utilizes the multi-beam monopulse angle-measuring method based on beam selection method to obtain, and this angle on target is directly used in the detection of radar and controls.

The present invention is that the selection of only passing through wave beam under existing many horn feeds parabola antenna hardware system condition improves angle measurement accuracy, do not increase calculated amount, and the angle measurement beam combination is that off-line is determined, after determining when processing the real time radar signal process selected of repeated optimization again.

Embodiment 3

Based on the multi-beam monopulse angle-measuring method of beam selection method with embodiment 1～2:

Feasibility of the present invention and advantage can further illustrate by following experiment.

Existing hypothetical target arrival bearing be elevation angle Φ=-2 °～2 °, echo signal arrival is arranged at interval of 0.1 °, utilizes Computer Simulation to form simultaneously 5 wave beams, No. one～No. five wave beams, 1 ° of adjacent two wave beam spacing, its wave beam maximal value is pointed to respectively the elevation angle-2 ° ,-1 °, 0 °, 1 °, 2 °, two adjacent beams form with the wave beam passage in signal to noise ratio (S/N ratio) be 25dB, noise is the multiple noise of Gauss, and experimental procedure and result are as follows:

Select two wave beams of 1 ° of spacing to do and analogous diagram is as shown in Figure 3 while differing from, wherein Fig. 3 (a) is antenna radiation pattern, there are four as shown in Fig. 3 (b) with wave beam, difference beam has four as shown in Fig. 3 (c), the mirror angular curve has four as Fig. 3 (d), after the optimal beam combination is determined, only there is one to be used for angle measurement in four mirror angular curves.

Select two wave beams of 2 ° of spacings to do and analogous diagram is as shown in Figure 4 while differing from, wherein Fig. 4 (a) is antenna radiation pattern, there are three as shown in Fig. 4 (b) with wave beam, difference beam has three as shown in Fig. 4 (c), the mirror angular curve has three as Fig. 4 (d), after the optimal beam combination is determined, only there is one to be used for angle measurement in three mirror angular curves.

Select two wave beams of 3 ° of spacings to do and analogous diagram is as shown in Figure 5 while differing from, wherein Fig. 5 (a) is antenna radiation pattern, there are two as shown in Fig. 5 (b) with wave beam, difference beam has two as shown in Fig. 5 (c), the mirror angular curve has two as Fig. 5 (d), after the optimal beam combination is determined, only there is one to be used for angle measurement in two mirror angular curves.

Select two wave beams of 4 ° of spacings to do and analogous diagram is as shown in Figure 6 while differing from, wherein Fig. 6 (a) is antenna radiation pattern, have one as shown in Fig. 6 (b) with wave beam, difference beam has one as shown in Fig. 6 (c), and the mirror angular curve has one as Fig. 6 (d).

(situation one) signal is during from elevation angle Φ=-2 °～-1 °, determine that by step 4 target is between wave beam and No. two wave beams, determine to adopt optimum No. one, angle measurement beam combination and No. four wave beam angle measurements according to the beam selection method of step 3, the root-mean-square error of angle measurement this moment is minimum, when adopting other combination, i.e. a wave beam and No. two wave beams, a wave beam and No. three wave beams, when a wave beam and No. five wave beam angle measurements, root-mean-square error is all larger, as shown in Figure 7, similarly relatively all embody to some extent in Fig. 8, Fig. 9 and Figure 10.

(situation two) signal is during from elevation angle Φ=-1 °～0 °, determine that by step 4 target is between No. two wave beams and No. three wave beams, beam selection method according to step 3, when target during from elevation angle Φ=-1 °～-0.6 °, the signal intensity that No. two wave beams receive is more than or equal to the signal intensity that No. three wave beams receive, adopt No. one and No. four wave beam angle measurement root-mean-square errors minimum; When target during from elevation angle Φ=-0.6 °～-0 °, the signal intensity that No. two wave beams receive is less than the signal intensity that No. three wave beams receive, adopt No. one and No. five wave beam angle measurement root-mean-square errors minimum, as shown in Figure 8.

(situation three) signal is during from elevation angle Φ=0 °～1 °, determine that by step 4 target is between No. three wave beams and No. four wave beams, beam selection method according to step 3, when target during from elevation angle Φ=0 °～0.6 °, the signal intensity that No. three wave beams receive, more than or equal to the signal intensity that No. four wave beams receive, adopts No. one No. five wave beam angle measurement root-mean-square errors minimum; When target during from elevation angle Φ=0.6 °～1 °, the signal intensity that No. three wave beams receive is less than the signal intensity that No. four wave beams receive, adopt No. two and No. five wave beam angle measurement root-mean-square errors minimum, as shown in Figure 9.

(situation four) signal is during from elevation angle Φ=1 °～2 °, determine that by step 4 target is between No. four wave beams and No. five wave beams, determine to adopt No. two and No. five wave beam angle measurements according to the beam selection method of step 3, the root-mean-square error of angle measurement this moment is minimum, as shown in figure 10.

Therefore, the beam selection criterion of determining based on the multi-beam monopulse angle-measuring method of beam selection method as shown in figure 11.Can be found out by Fig. 7, Fig. 8, Fig. 9, Figure 10, the present invention selects the angle measurement wave beam to make angle measurement accuracy carry in radar antenna covering spatial domain and improve at ball by optimization, has proved the correctness of the angle-measuring method that the present invention proposes.

To sum up, the monopulse of the multi-beam based on beam selection method angle-measuring method of the present invention, its detecting step is: (1) pitching dimension forms M wave beam simultaneously, 1 ° of each beam step, and it is interval that its covering spatial domain is divided into M-1 angle measurement; (2) receive signal amplitude difference and ratio foundation mirror angular curve according to ideal antenna under off-line case; (3) for the interval θ of each angle measurement _{I, i+1}Select optimum wave beam spacing to reach and wave beam; (4) determine according to the real goal echo strength the interval θ of angle measurement that target belongs to _{I, i+1}(5) utilize step (3) off-line to determine optimum angle measurement beam combination, the radar real-time target echo that this beam combination is received calculates poor and ratio, utilizes poor and than search for angle on target in mirror angular curve corresponding to this beam combination.It is little that the present invention mainly solves under the existing hardware system condition two wave beam monopulse angle measurement spatial domain coverages, the problem that precision is low, angle measurement beam combination of the present invention is that off-line is determined, the process selected of repeated optimization again while processing the real time radar signal, calculated amount is little, in the situation that the optimization of a plurality of wave beam is selected optimum wave beam spacing and with wave beam, carries out angle measurement, angle measurement accuracy is high, make the angle measurement effect be optimized, be used for covering the large ball in spatial domain and carry the detection of radar to angle on target.

Claims (4)

1. the monopulse of the multi-beam based on a beam selection method angle-measuring method, is characterized in that: comprise the steps:

Step 1 is utilized radar parabola feed antenna to form simultaneously M wave beam and it is covered spatial domain and is divided into M-1 angle measurement interval: the angle between two adjacent beams axles is as an angle measurement interval, and it is θ that M wave beam covers spatial domain division result _1,2, θ _2,3θ _{I, i+1}, 1≤i≤M-1 wherein, θ _{I, i+1}For the folded angle of the beam axis of the beam axis of wave beam i and wave beam i+1;

Step 2 receives signal amplitude difference according to ideal antenna under off-line case and ratio is set up the mirror angular curve: according to antenna receiving signal, every two wave beams are done and are obtained and wave beam, do difference and obtain difference beam, differ from the mirror angular curve that obtains its correspondence with ratio;

Step 3 is for the interval θ of each angle measurement _{I, i+1}Select optimum wave beam spacing to reach and wave beam: for the interval θ of each angle measurement _{I, i+1}Selected a kind of angle measurement wave beam spacing δ ₁, by comparer determine under this wave beam spacing condition with the beam gain maximal value

1≤k wherein ₁≤ M-1; Selected another angle measurement wave beam spacing δ ₂, in like manner select under this wave beam spacing condition with the beam gain maximal value 1≤k wherein ₂≤ M-2, the rest may be inferred, obtains altogether M-1 and beam gain maximal value, and these and the beam gain maximal value wave beam spacing corresponding with it are multiplied each other, the long-pending descending sequence that to multiply each other, in ranking results, corresponding two wave beams of maximal value are optimum angle measurement beam combination;

Step 4 radar antenna receives signal in real time, according to the real goal echo strength, determines the interval θ of angle measurement that target belongs to _{I, i+1}: the signal to each single channel receives, sort according to the signal amplitude value is descending, corresponding two wave beams of its first two signal amplitude value, the folded angular regions of this two beam axis is the angular interval θ that target belongs to _{I, i+1}

Step 5 detects angle on target: utilize step 3 off-line to determine optimum angle measurement beam combination, the radar real-time target echo that this beam combination is received calculates poor and ratio, utilize poor and than search for angle on target in mirror angular curve corresponding to this beam combination, this angle is the angle on target that utilization obtains based on the multi-beam monopulse angle-measuring method of beam selection method.

2. the monopulse of the multi-beam based on beam selection method angle-measuring method according to claim 1, wherein cover the division in spatial domain to M wave beam in step 1, comprises the steps:

(1a) feed of antenna is a plurality of loudspeaker, homeotropic alignment on the focal plane of parabolic reflector, and each loudspeaker are off-focal in succession, therefore form a partly overlapping M wave beam each other, 1 ° of adjacent two wave beam spacing on elevation plane;

(1b) will be from the echo signal between the adjacent beam axis of two-phase as an angle measurement interval, the division result is θ _1,2, θ _2,3θ _{I, i+1}, 1≤i≤M-1 wherein.

3. the monopulse of the multi-beam based on beam selection method angle-measuring method according to claim 2, wherein step 2 is described receives signal amplitude difference according to ideal antenna and, than setting up the mirror angular curve, carries out as follows under off-line case:

(2a) according to ideal antenna, receive signal spatial domain is scanned, obtain and wave beam F _Σ(θ), difference beam F _Δ(θ), do that ratio is differed from and compare

Thereby set up the mirror angular curve;

(2b) every two adjacent beams are set up the mirror angular curve and can be obtained M-1 bar mirror angular curve, the wave beam combination of two that spacing is 2 ° can obtain M-2 bar mirror angular curve, the wave beam combination of two that spacing is 3 ° can obtain M-3 bar mirror angular curve, the rest may be inferred, the wave beam combination of two of spacing i ° can obtain M-i bar mirror angular curve, wherein 1≤i≤M-1.

4. the monopulse of the multi-beam based on beam selection method angle-measuring method according to claim 3, wherein step 3 is described for the interval θ of each angle measurement _{I, i+1}Select optimum wave beam spacing to reach and wave beam, carry out as follows:

(3a) wave beam spacing δ ₁In the time of=1 °, obtaining with beam gain is S _1,2(θ), S _2,3(θ), S _3,4(θ) ... S _{M-1, M}(θ), its descending sequence is obtained maximal value 1≤k wherein ₁≤ M-1;

(3b) wave beam spacing δ ₂In the time of=2 °, obtaining with beam gain is S _1,3(θ), S _2,4(θ), S _3,5(θ) ... S _{M-2, M}(θ), its descending sequence is obtained maximal value

1≤k wherein ₂≤ M-2;

(3c) the rest may be inferred, wave beam spacing δ _i=i °, wherein during 1≤i≤M-1, obtaining with beam gain is S _{1, i}(θ), S _2,2+i(θ), S _3,3+i(θ) ... S _{M-i, M}(θ), its descending sequence is obtained maximal value

1≤k wherein _i≤ M-i;

(3d) right

Descending sequence, try to achieve its maximal value

1≤j≤M-1 wherein.δ _jBe the wave beam spacing that select,

Be angle measurement and the wave beam that select, thereby determine angle measurement beam combination and corresponding mirror angular curve.

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