CN115015846B - Generalized self-adaptive monopulse angle measurement method based on conformal array antenna - Google Patents
Generalized self-adaptive monopulse angle measurement method based on conformal array antenna Download PDFInfo
- Publication number
- CN115015846B CN115015846B CN202210588222.4A CN202210588222A CN115015846B CN 115015846 B CN115015846 B CN 115015846B CN 202210588222 A CN202210588222 A CN 202210588222A CN 115015846 B CN115015846 B CN 115015846B
- Authority
- CN
- China
- Prior art keywords
- array antenna
- conformal array
- adaptive
- subarray
- self
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000691 measurement method Methods 0.000 title claims abstract description 45
- 238000005259 measurement Methods 0.000 claims abstract description 59
- 239000013598 vector Substances 0.000 claims abstract description 54
- 230000014509 gene expression Effects 0.000 claims abstract description 31
- 238000012937 correction Methods 0.000 claims abstract description 28
- 239000011159 matrix material Substances 0.000 claims abstract description 15
- 230000036961 partial effect Effects 0.000 claims abstract description 14
- 230000003044 adaptive effect Effects 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 15
- 238000012545 processing Methods 0.000 claims description 12
- 238000004422 calculation algorithm Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 238000004088 simulation Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 4
- 230000001629 suppression Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 238000000342 Monte Carlo simulation Methods 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 238000007476 Maximum Likelihood Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005315 distribution function Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/36—Means for anti-jamming, e.g. ECCM, i.e. electronic counter-counter measures
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Variable-Direction Aerials And Aerial Arrays (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention discloses a generalized self-adaptive monopulse angle measurement method based on a conformal array antenna, which comprises the following steps: acquiring a guiding vector direction cosine expression of a target signal received by a conformal array antenna and a subarray-level self-adaptive monopulse ratio; obtaining a partial guide function expression of a conformal array antenna transmitting signal guide vector; solving a slope correction matrix and a deviation correction amount of the monopulse ratio of the conformal array antenna, and constructing a generalized monopulse angle measurement formula of the conformal array antenna; and (3) obtaining the directional cosine of the target signal by using a conformal array antenna generalized monopulse angle measurement formula, and further obtaining the pitch angle and the azimuth angle of the target signal. The angle measurement method does not depend on the slope of a monopulse ratio curve obtained according to the self-adaption and difference beam patterns, and the angle measurement error is minimum; the system freedom is not additionally lost, and good angle measurement performance can be maintained along with the increase of the number of side lobe interference.
Description
Technical Field
The invention belongs to the technical field of radar signal processing, and particularly relates to a generalized self-adaptive monopulse angle measurement method based on a conformal array antenna.
Background
With the advancement of phased array radar technology, conformal array antennas are an important direction of modern radar development. The conformal array antenna is arranged on the radar guide head, so that the radar guide head not only has good aerodynamic performance, but also can effectively reduce the radar scattering sectional area, thereby enabling the radar to have low detectability. The conformal array antenna self-adaptive monopulse angle measurement technology is researched, and the angle tracking of the radar to the target can be realized.
Under the actual situation, the number of the array elements of the conformal array antenna is huge, the number of channels required by array element level self-adaptive processing is large, and the system structure is complex, so that in order to reduce the cost, simplify the system structure, reduce the calculation amount of an algorithm, reduce the complexity of the system, meet the requirement of the real-time performance of the system, and the subarray division processing is required for the conformal array antenna. Currently, there is a great deal of research on the angle measurement problem of a linear array or an area array, and the existing self-adaptive single-pulse angle measurement method can be roughly divided into three categories: the first is a sum and difference beam simultaneous zero setting technology, which requires known interference directions and has poor self-adaptive capacity; the second type is based on self-adaptive pattern shape-keeping technology, namely, self-adaptive pattern shape-keeping is carried out by adopting methods such as linear constraint and the like, so that the single-pulse angle discrimination characteristic is not distorted as much as possible; the third category is monopulse goniometry based on the maximum likelihood method, proposed by Davies et al based on equidistant linear array models, but this method requires the difference beam to be the derivative of the sum beam, which is not satisfactory in most applications. The Nickel provides an adaptive monopulse angle measurement algorithm under the condition of random sum and difference beams on the basis, and the adaptive monopulse angle measurement algorithm has wider applicability.
There are few published documents for the study of conformal array antenna goniometry algorithms. When the conformal array antenna adopts the traditional self-adaptive monopulse angle measurement, although the angle measurement of a target can be realized while interference signals are restrained, the angle measurement performance depends on a sum-difference beam pattern, and when the interference number is more or the interference is positioned near a main beam, the null formed by the self-adaptive beam can cause the distortion of the main beam of the sum-difference beam, so that the traditional self-adaptive monopulse angle measurement error is increased; zhao Yingjun et al in 2013 propose a conformal array antenna constraint self-adaptive monopulse angle measurement method, which realizes main beam shape retention by applying constraint conditions to main beams, is beneficial to ensuring sum and difference monopulse angle measurement performance, but the applied additional constraint conditions consume the airspace degree of freedom of a system.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a generalized self-adaptive monopulse angle measurement method based on a conformal array antenna, which does not depend on the slope of monopulse ratio curves obtained according to self-adaptive and differential beam patterns and does not lose airspace degrees of freedom, and when a conformal array antenna guiding vector is solved, the shielding effect of the conformal array antenna and the directional pattern difference of each array element antenna are taken into consideration, wherein the conformal array antenna can be a uniform conformal array antenna or a sparse conformal array antenna obtained after array optimization. The technical problems to be solved by the invention are realized by the following technical scheme:
The invention provides a generalized self-adaptive monopulse angle measurement method based on a conformal array antenna, which comprises the following steps:
S1: acquiring a guiding vector direction cosine expression of a target signal received by a conformal array antenna and a subarray-level self-adaptive monopulse ratio;
s2: obtaining a partial guide function expression of a conformal array antenna transmitting signal guide vector;
s3: solving a slope correction matrix and a deviation correction amount of the monopulse ratio of the conformal array antenna, and constructing a generalized monopulse angle measurement formula of the conformal array antenna;
s4: and (3) obtaining the directional cosine of the target signal by using a conformal array antenna generalized monopulse angle measurement formula, and further obtaining the pitch angle and the azimuth angle of the target signal.
In one embodiment of the present invention, the S1 includes:
S1.1: obtaining a guiding vector direction cosine expression of a target signal received by a conformal array antenna;
S1.2: performing dimension reduction processing on the conformal array antenna to obtain subarray-level self-adaptive sum wave beam output power and subarray-level self-adaptive pitch difference wave beam output power of the conformal array antenna and subarray-level self-adaptive azimuth difference wave beam output power;
s1.3: and obtaining the subarray level pitch-dimension self-adaptive monopulse ratio and the subarray level azimuth-dimension self-adaptive monopulse ratio of the conformal array antenna by utilizing each output power.
In one embodiment of the present invention, the S1.1 includes:
Obtaining a directional vector cosine expression of a target signal received by a conformal array antenna:
Wherein r i＝[xi yi zi represents the coordinates of the ith antenna element, i=1, 2, … N, N represents the total number of antenna elements, f 1 f2 ... fN represents the corresponding pattern of each antenna element, Which represents the directional cosine of the target signal, θ represents the pitch angle of the target signal,Represents the azimuth angle of the target signal, and λ represents the target signal wavelength;
Will be Denoted v= [ u u 'v ], resulting in an expansion a (u, u', v) of the directional cosine expression of the target signal steering vector:
in one embodiment of the present invention, the S1.2 includes:
Dividing the conformal array antenna into a plurality of subarrays, and respectively obtaining subarray-level self-adaptive sum wave beam weight vectors w sub_∑ and subarray-level self-adaptive pitching difference wave beam weight vectors And subarray level self-adaptive azimuth difference beam weight vector
By means of the use of w sub_∑,AndThe method comprises the steps of respectively obtaining subarray level self-adaption and beam output power, subarray level self-adaption pitching difference beam output power and subarray level self-adaption azimuth difference beam output power:
Psub_∑＝wsub_∑x
where x represents the incoming signal received by the conformal array antenna.
In one embodiment of the present invention, the S1.3 includes:
Utilizing subarray level self-adaptive sum beam output power P sub_∑ and subarray level self-adaptive pitch difference beam output power Obtaining a subarray-level pitching dimension self-adaptive monopulse ratio of the conformal array antenna:
beam output power by utilizing subarray level self-adaption sum beam output power P sub_Σ and subarray level self-adaption azimuth difference Obtaining a subarray-level azimuth dimension self-adaptive monopulse ratio of the conformal array antenna:
in one embodiment of the present invention, the S2 includes:
Obtaining a partial derivative function expression of the conformal array antenna steering vector according to a derivative rule:
Where a u,t represents the expression of the partial derivative function of the conformal array antenna steering vector a (v) with respect to u at v t, a v,t represents the expression of the partial derivative function of the conformal array antenna steering vector a (v) with respect to v at v t, θt,Representing the pitch and azimuth angles, respectively, of the signals transmitted by the conformal array antenna.
In one embodiment of the present invention, the generalized monopulse angle measurement formula of the conformal array antenna is:
Where u t and v t represent the beam directions of the signals transmitted by the radar conformal array antenna, V t＝sinθt, real {.cndot }, represents the real part taking operation,A slope correction matrix representing a single pulse ratio,Indicating the deviation correction amount.
In one embodiment of the invention, solving the slope correction matrix and the offset correction of the monopulse ratio of the conformal array antenna comprises:
According to the subarray level self-adaption sum wave beam weight vector w sub_∑ and the subarray level self-adaption pitching difference wave beam weight vector And subarray level self-adaptive azimuth difference beam weight vectorObtaining a slope correction matrix and a deviation correction amount:
compared with the prior art, the invention has the beneficial effects that:
1. When the conformal array antenna has interference close to a main beam in an external environment, compared with the existing subarray-level traditional self-adaptive single-pulse angle measurement method and subarray-level constraint self-adaptive single-pulse angle measurement method, the generalized self-adaptive single-pulse angle measurement method based on the conformal array antenna has better angle measurement performance while realizing interference suppression. Because the subarray level traditional self-adaptive monopulse is used for inhibiting interference, null is formed at an interference position, but because the interference is closer to a main lobe, a pitching dimension difference beam pattern is distorted, an angle discrimination curve is seriously distorted, and the subarray level traditional self-adaptive monopulse pitching dimension angle measurement error is sharply increased; and the subarray level constraint self-adaptive monopulse applies constraint conditions to the main beam, so that the differential beam pattern is conformal, and loss caused by a part of nulls can be counteracted. The angle measurement method of the invention does not depend on the slope of the monopulse ratio curve obtained according to the self-adaptive and differential beam patterns, and the angle measurement error is minimum.
2. When the number of side lobe interference is large, compared with the subarray level constraint self-adaptive single pulse angle measurement method, the angle measurement error is smaller while the interference suppression is realized. And because the subarray level constraint self-adaptive monopulse applies constraint conditions to the main beam, the main beam shape retention is realized, and the additional constraint conditions cause the loss of the airspace degree of freedom of the system. When the number of interference exceeds the spatial degree of freedom remained after constraint conditions are applied, the subarray-level constraint self-adaptive monopulse angle discrimination curve is distorted, so that the angle measurement error of the method is increased. The angle measurement method of the invention does not additionally lose the system freedom degree, and can keep better angle measurement performance along with the increase of the number of side lobe interference.
3. Compared with the conformal array antenna array element level self-adaptive processing, the conformal array antenna sub-array level generalized self-adaptive single pulse angle measurement method can simplify the system structure, reduce the calculated amount of an algorithm, reduce the complexity of the system and simultaneously meet the requirement of the real-time performance of the system.
The present invention will be described in further detail with reference to the accompanying drawings and examples.
Drawings
Fig. 1 is a flowchart of a generalized adaptive monopulse angle measurement method based on a conformal array antenna according to an embodiment of the present invention;
fig. 2 is a conical conformal array model under a rectangular coordinate system according to an embodiment of the present invention;
FIG. 3 (a) is a graph of pitch dimension angle measurement error for three angle measurement methods in the presence of one sidelobe disturbance and one near main beam disturbance;
FIG. 3 (b) is an azimuthal angle measurement error plot for three angle measurement methods in the presence of a sidelobe disturbance and a disturbance near the main beam;
FIG. 4 (a) is a pitch dimension angle measurement error curve for three angle measurement methods as the number of sidelobe interference increases;
fig. 4 (b) is an azimuth dimension angle measurement error curve of three angle measurement methods as the number of side lobe interference increases.
Detailed Description
In order to further explain the technical means and effects adopted by the invention to achieve the preset aim, the following describes a generalized self-adaptive single-pulse angle measurement method based on a conformal array antenna according to the invention in detail with reference to the attached drawings and the specific embodiments.
The foregoing and other features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments when taken in conjunction with the accompanying drawings. The technical means and effects adopted by the present invention to achieve the intended purpose can be more deeply and specifically understood through the description of the specific embodiments, however, the attached drawings are provided for reference and description only, and are not intended to limit the technical scheme of the present invention.
It should be noted that in this document relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in an article or device comprising the element.
Referring to fig. 1, fig. 1 is a flowchart of a generalized adaptive monopulse angle measurement method based on a conformal array antenna according to an embodiment of the present invention, where the method includes the following steps:
S1: and acquiring a guiding vector direction cosine expression of a target signal received by the conformal array antenna and a subarray-level self-adaptive monopulse ratio.
Due to the particularity of the structure of the conformal array antenna, when an incoming wave signal deviates from a visual axis, part of array elements are shielded by an elastomer, so that the incoming wave signal cannot be received, and the array elements are in a non-working state at the moment, so that the shielding effect brought by the conformal array antenna is reflected. Because each array element is positioned at different space positions and not in the same plane, the working environments of the array elements are different, and the normal direction of each array element is perpendicular to the surface of a conformal carrier (the carrier attached by the conformal array antenna), so that the main beam directions of the antenna patterns of the array elements are different. When external signals are incident to the conformal array antenna, the radiation gain of each array element does not contribute equally to the whole conformal array antenna, so that the antenna direction diagrams of the array elements of each antenna have differences. When solving the guiding vector of the incoming wave signal received by the conformal array antenna, the shielding effect and the directional diagram difference of each array element antenna are needed to be taken into consideration, the guiding vector of the obtained target signal is a (v), and the self-adaptive weight vector can be obtained by combining the self-adaptive beam forming criterion and algorithm.
In this embodiment, step S1 includes:
S1.1: and obtaining a directional vector direction cosine expression of the target signal received by the conformal array antenna.
Assuming that the incoming wave signal received by the conformal array antenna is x, the incoming wave signal can be expressed as:
Wherein t represents the snapshot number, s (t) is the signal amplitude of the target signal, N represents the noise signal, the noise signals of the array elements are uncorrelated and are Gaussian white noise, N-N (0, delta 2I),N(0,δ2 I) are normal distribution function expressions, I represents an identity matrix, delta 2 represents the variance of white noise data, Representing the steering vector of the target signal to be calculated, θ represents the pitch angle of the target signal to be calculated,Representing the azimuth of the incoming wave signal to be calculated.
In this embodiment, taking the shielding effect of the conformal array antenna and the directional diagram difference of each array element antenna into account, the guiding vector direction cosine expression of the target signal is obtained as follows:
wherein, for the ith antenna element, the coordinates of the element i are r i＝[xi yi zi, i=1, 2, … N, N represents the total number of antenna elements, Is simply denoted as v= [ u u' v ], where v denotes the directional cosine of the target signal, f 1 f2 ... fN denotes the corresponding directional pattern of each antenna element, λ denotes the wavelength of the target signal, θ denotes the pitch angle of the target signal,Representing the azimuth of the target signal.
An expansion a (u, u', v) of the directional cosine expression of the target signal steering vector can then be obtained:
s1.2: and performing dimension reduction processing on the conformal array antenna to obtain subarray-level self-adaptive sum wave beam output power and subarray-level self-adaptive pitching difference wave beam output power and subarray-level self-adaptive azimuth difference wave beam output power of the conformal array antenna.
The received incoming wave signal is assumed to be x, the adaptive weight vector w opt can be obtained by combining an adaptive beam forming criterion and an algorithm, in practical situations, the number of the array elements of the conformal array antenna is huge, the number of channels required by array element level adaptive processing is more, and the system structure is complex, so that in order to reduce the cost, the conformal array element is divided into a plurality of subarrays, and dimension reduction processing is performed. Assuming that the obtained subarray-level self-adaptive sum beam weight vector of the conformal array antenna and the subarray-level self-adaptive pitching difference beam weight vector are w sub_∑ respectively,AndThe sub-array level self-adaptive sum beam output power, the sub-array level self-adaptive pitch difference beam output power and the sub-array level self-adaptive azimuth difference beam output power are respectively:
Psub_∑＝wsub_∑x
s1.3: and obtaining the subarray level pitch-dimension self-adaptive monopulse ratio and the subarray level azimuth-dimension self-adaptive monopulse ratio of the conformal array antenna by utilizing each output power.
In the case of adaptive monopulse angle measurement, it is necessary to use an adaptive monopulse ratio (i.e., a ratio of a difference beam output to a sum beam output), and therefore, a subarray-level pitch-dimension adaptive monopulse ratio R u and a subarray-level azimuth-dimension adaptive monopulse ratio R v are calculated using the output powers obtained in step S1.2, respectively.
Specifically, the subarray-level adaptive sum beam output power P sub_∑ and the subarray-level adaptive pitch-difference beam output power are utilizedObtaining a subarray-level pitching dimension self-adaptive monopulse ratio of the conformal array antenna:
Beam output power by utilizing subarray level self-adaption sum beam output power P sub_∑ and subarray level self-adaption azimuth difference Obtaining a subarray-level azimuth dimension self-adaptive monopulse ratio of the conformal array antenna:
s2: and acquiring a conformal array antenna transmitting signal guiding vector partial derivative function expression.
If the conformal array antenna is horizontally placed under the geodetic coordinate system, taking a common conical conformal array or a cylindrical conformal array as an example, the cross section perpendicular to the axis is a circle, and the symmetry is provided. As shown in FIG. 2, the symmetry axis of the conformal array antenna is parallel to the Y axis when the conformal array antenna is horizontally placed, and the Y coordinates of each array element on any layer of circular ring are the same. Assume that the direction of the signal transmitted by the known radar conformal array antenna isThe direction cosine is now denoted by v t,Is abbreviated as v t＝[ut u′t vt.
The cosine expression of the direction of the steering vector of the target signal received by the conformal array antenna is given asSince the expressions of the various signal steering vectors are uniform, the directional cosine expression of the signal steering vector emitted by the conformal array antenna can be obtained:
Assuming that the array element coordinates of the known conformal array antenna are r= [ x y z ], x represents the abscissa, y represents the ordinate, z represents the ordinate, and the partial derivative function expression of the conformal array antenna guiding vector can be obtained according to the derivative rule, which are respectively:
Where a u,t represents the expression of the partial derivative function of the conformal array antenna steering vector a (v) with respect to u at v t, a v,t represents the expression of the partial derivative function of the conformal array antenna steering vector a (v) with respect to v at v t, θt,Representing the pitch and azimuth angles, respectively, of the signals transmitted by the conformal array antenna.
S3: and solving a slope correction matrix and a deviation correction quantity of the monopulse ratio of the conformal array antenna, and constructing a generalized monopulse angle measurement formula of the conformal array antenna.
In many radar systems, the received signal for each element is not available for practical use, e.g., the difference beam may be obtained by sub-array rank beamforming; when the array plane is a non-uniform array such as a sparse array, and the beams cannot be uniformly weighted; the noise component in the incoming wave signal x is not necessarily white noise due to the presence of the interfering signal.
In view of the above factors, the generalized monopulse angle measurement formula of the conformal array antenna can be obtained in the embodiment:
Where u t and v t represent the beam directions of the signals transmitted by the radar conformal array antenna, V t＝sinθt, real {.cndot }, represents the real part taking operation,A slope correction matrix representing a single pulse ratio,Indicating the deviation correction amount. R u and R v represent the single pulse ratio in pitch and azimuth, respectively.
S3.2: and solving a conformal array antenna slope correction matrix and a deviation correction amount, and performing linear compensation on the self-adaptive monopulse ratio.
In practical situations, the number of array elements of the conformal array antenna is huge, the number of channels required by array element level self-adaptive processing is large, and the system structure is complex, so in order to reduce the cost, the angle measurement method of the embodiment of the invention reduces the dimension to the subarray level for processing, and further solves the slope correction matrix and the deviation correction amount to obtain:
Wherein w sub_Σ represents the adaptive sum beam weight vector of the conformal array antenna subarray level, AndRespectively representing the self-adaptive pitching difference beam weight vector and the azimuth difference beam weight vector of the conformal array antenna subarray level, and obtaining the weight vector in the step S1; a u,t and a v,t represent partial derivative function expressions of the radar-emission-signal steering vector that have been solved in step S2.
S4: and (3) obtaining the directional cosine of the target signal by using a conformal array antenna generalized monopulse angle measurement formula, and further obtaining the pitch angle and the azimuth angle of the target signal.
Specifically, the slope correction matrix to be obtainedDeviation correction amountThe value of the target signal is replaced by a generalized monopulse angle measurement formula, so that the direction cosine u and the direction cosine v of the target signal can be obtained, and the angle of the target signal can be further solved
Further, the effect of the generalized adaptive monopulse angle measurement method based on the conformal array antenna in the embodiment of the invention is further illustrated by the following simulation test:
(1) Simulation conditions
In the simulation experiment of this embodiment, taking a conical conformal array antenna as an example, a coordinate system is established as shown in fig. 2, a pitch angle is defined as an included angle between the projection of an incoming wave signal on an XOY plane and the signal itself,The azimuth angle of an incoming wave signal is represented, an included angle between projection of the incoming wave signal on an XOY plane and the Y axis forward direction is defined as the azimuth angle, the cross section of the incoming wave signal perpendicular to the conical axis is a circle, symmetry is achieved, the conformal array antenna is divided into 12 sub-array channels, and a nine-point constraint method is adopted by the sub-array level constraint self-adaptive monopulse angle measurement method. The angle measurement performance of three methods, namely a subarray level traditional self-adaptive single pulse angle measurement method (called traditional single pulse for short) and a subarray level constraint self-adaptive single pulse angle measurement method (called constraint single pulse for short), is compared and analyzed.
(2) Emulation content
Simulation experiment one: when there is one sidelobe interference and one interference close to the main beam, the angle measurement errors of the three angle measurement methods are compared. Assuming that the target signal is from (0 ° ), there is an interference (3 °), 0 °) closer to the main beam, and a sidelobe interference (15 °, -30 °), the interference-to-noise ratio is 60dB, and monte carlo experiments are performed under different signal-to-noise ratios, and fig. 3 (a) and fig. 3 (b) are a pitch dimension angle measurement error curve and an azimuth dimension angle measurement error curve of three different angle measurement methods, respectively.
Simulation experiment II: and changing the number of side lobe interference, and comparing the change trend of error curves of the three angle measuring methods.
Assuming beam pointing (0 ° ), fixed signal-to-noise ratio is 20dB, both dry-to-noise ratios are set to 60dB, the number of side lobe interference is changed for monte carlo experiments, and fig. 4 (a) and fig. 4 (b) are pitch dimension angle measurement error curves and azimuth dimension angle measurement error curves of three different angle measurement methods, respectively.
(3) Simulation result analysis
As can be seen from fig. 3 (a) and fig. 3 (b), when there is a sidelobe interference and an interference close to the main lobe, the angle measurement error of the conventional single-pulse pitch dimension of the subarray level is the largest, and the angle measurement error of the angle measurement method in the embodiment of the invention is always lower than that of the constrained adaptive single pulse of the subarray level. In summary, the angle measurement errors of the three methods are reduced along with the increase of the input signal-to-noise ratio, and when interference close to the main beam exists in the external environment, the angle measurement performance of the angle measurement method of the embodiment of the invention is superior to that of the subarray-level constraint self-adaptive monopulse angle measurement.
As can be seen from fig. 4 (a) and fig. 4 (b), with the increase of the number of side lobe interference, the angle measurement error of the conventional adaptive monopulse at the subarray level is always larger than that of the other two methods, when the number of interference is smaller than 3, the angle measurement error of the constrained adaptive monopulse at the subarray level is smaller than that of the generalized adaptive monopulse at the subarray level in the embodiment of the invention, and when the number of interference exceeds 3, the angle measurement error of the constrained adaptive monopulse at the subarray level is sharply increased, and thereafter, the angle measurement error of the angle measurement method of the embodiment of the invention is always smaller than that of the constrained adaptive monopulse at the subarray level.
In addition, sub-array level constrained adaptive monopulse shape preservation of the main beam pattern by imposing additional constraints on the main beam, but the additional constraints lose spatial freedom. When the number of interference is smaller than the space domain degrees of freedom remained after constraint conditions are applied, the sub-array level constraint self-adaptive single-pulse angle measurement error is smaller, and the angle measurement performance is better; when the number of interference exceeds the spatial degree of freedom remained after constraint conditions are applied, the subarray-level constraint self-adaptive monopulse angle discrimination curve is distorted, so that the angle measurement error of the method is increased. In summary, with the increase of the number of sidelobe interference, the angle measurement method of the embodiment of the invention does not depend on the slope of the monopulse ratio curve obtained according to the self-adaption and the difference beam pattern, does not lose the degree of freedom of the system, and can keep better angle measurement performance.
When the conformal array antenna has interference close to a main beam in an external environment, compared with the existing subarray-level traditional self-adaptive single-pulse angle measurement method and subarray-level constraint self-adaptive single-pulse angle measurement method, the generalized self-adaptive single-pulse angle measurement method based on the conformal array antenna has better angle measurement performance while realizing interference suppression. Because the subarray level traditional self-adaptive monopulse is used for inhibiting interference, null is formed at an interference position, but because the interference is closer to a main lobe, a pitching dimension difference beam pattern is distorted, an angle discrimination curve is seriously distorted, and the subarray level traditional self-adaptive monopulse pitching dimension angle measurement error is sharply increased; and the subarray level constraint self-adaptive monopulse applies constraint conditions to the main beam, so that the differential beam pattern is conformal, and loss caused by a part of nulls can be counteracted. The angle measurement method of the invention does not depend on the slope of the monopulse ratio curve obtained according to the self-adaptive and differential beam patterns, and the angle measurement error is minimum. When the number of side lobe interference is large, compared with the subarray level constraint self-adaptive single pulse angle measurement method, the angle measurement error is smaller while the interference suppression is realized. And because the subarray level constraint self-adaptive monopulse applies constraint conditions to the main beam, the main beam shape retention is realized, and the additional constraint conditions cause the loss of the airspace degree of freedom of the system. When the number of interference exceeds the spatial degree of freedom remained after constraint conditions are applied, the subarray-level constraint self-adaptive monopulse angle discrimination curve is distorted, so that the angle measurement error of the method is increased. The angle measurement method of the invention does not additionally lose the system freedom degree, and can keep better angle measurement performance along with the increase of the number of side lobe interference.
In addition, compared with the conformal array antenna array element level self-adaptive processing, the conformal array antenna subarray level generalized self-adaptive monopulse angle measurement method can simplify the system structure, reduce the calculated amount of an algorithm, reduce the complexity of the system and simultaneously meet the requirement of the real-time performance of the system.
The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.
Claims (3)
1. The generalized self-adaptive monopulse angle measurement method based on the conformal array antenna is characterized by comprising the following steps of:
S1: acquiring a guiding vector direction cosine expression of a target signal received by a conformal array antenna and a subarray-level self-adaptive monopulse ratio;
s2: obtaining a partial guide function expression of a conformal array antenna transmitting signal guide vector;
s3: solving a slope correction matrix and a deviation correction amount of the monopulse ratio of the conformal array antenna, and constructing a generalized monopulse angle measurement formula of the conformal array antenna;
S4: the method comprises the steps of obtaining the directional cosine of a target signal by using a conformal array antenna generalized monopulse angle measurement formula, and further obtaining the pitch angle and the azimuth angle of the target signal;
Specifically, the S1 includes:
S1.1: obtaining a guiding vector direction cosine expression of a target signal received by a conformal array antenna;
S1.2: performing dimension reduction processing on the conformal array antenna to obtain subarray-level self-adaptive sum wave beam output power and subarray-level self-adaptive pitch difference wave beam output power of the conformal array antenna and subarray-level self-adaptive azimuth difference wave beam output power;
S1.3: obtaining a subarray level pitch-dimension self-adaptive monopulse ratio and a subarray level azimuth-dimension self-adaptive monopulse ratio of the conformal array antenna by utilizing each output power;
the S1.1 comprises:
Obtaining a directional vector cosine expression of a target signal received by a conformal array antenna:
Wherein r i＝[xiyizi represents the coordinates of the ith antenna element, i=1, 2, … N, N represents the total number of antenna elements, f 1f2...fN represents the corresponding pattern of each antenna element, Which represents the directional cosine of the target signal, θ represents the pitch angle of the target signal,Represents the azimuth angle of the target signal, and λ represents the target signal wavelength;
Will be Denoted v= [ uu 'v ], resulting in an expansion a (u, u', v) of the directional cosine expression of the target signal steering vector:
the step S2 comprises the following steps:
Obtaining a partial derivative function expression of the conformal array antenna steering vector according to a derivative rule:
Where a u,t represents the expression of the partial derivative function of the conformal array antenna steering vector a (v) with respect to u at v t, a v,t represents the expression of the partial derivative function of the conformal array antenna steering vector a (v) with respect to v at v t, Respectively representing the pitch angle and the azimuth angle of a signal transmitted by the conformal array antenna;
the generalized monopulse angle measurement formula of the conformal array antenna is as follows:
Where u t and v t represent the beam directions of the signals transmitted by the radar conformal array antenna, V t＝sinθt, real {.cndot }, represents the real part taking operation,A slope correction matrix representing a single pulse ratio,Representing deviation correction quantity, R u represents subarray level pitching dimension self-adaptive monopulse ratio of the conformal array antenna, and R v represents subarray level azimuth dimension self-adaptive monopulse ratio of the conformal array antenna;
Solving a slope correction matrix and a deviation correction amount of a conformal array antenna monopulse ratio, comprising:
According to the subarray level self-adaption sum wave beam weight vector w sub_∑ and the subarray level self-adaption pitching difference wave beam weight vector And subarray level self-adaptive azimuth difference beam weight vectorObtaining a slope correction matrix and a deviation correction amount:
2. the generalized adaptive monopulse angle measurement method based on a conformal array antenna according to claim 1, wherein S1.2 comprises:
Dividing the conformal array antenna into a plurality of subarrays, and respectively obtaining subarray-level self-adaptive sum wave beam weight vectors w sub_∑ and subarray-level self-adaptive pitching difference wave beam weight vectors And subarray level self-adaptive azimuth difference beam weight vector
By means of the use of w sub_∑,AndThe method comprises the steps of respectively obtaining subarray level self-adaption and beam output power, subarray level self-adaption pitching difference beam output power and subarray level self-adaption azimuth difference beam output power:
Psub_∑＝wsub_∑x
where x represents the incoming signal received by the conformal array antenna.
3. The generalized adaptive monopulse angle measurement method based on a conformal array antenna according to claim 2, wherein S1.3 comprises:
Utilizing subarray level self-adaptive sum beam output power P sub_∑ and subarray level self-adaptive pitch difference beam output power Obtaining a subarray-level pitching dimension self-adaptive monopulse ratio of the conformal array antenna:
Beam output power by utilizing subarray level self-adaption sum beam output power P sub_∑ and subarray level self-adaption azimuth difference Obtaining a subarray-level azimuth dimension self-adaptive monopulse ratio of the conformal array antenna:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210588222.4A CN115015846B (en) | 2022-05-27 | 2022-05-27 | Generalized self-adaptive monopulse angle measurement method based on conformal array antenna |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210588222.4A CN115015846B (en) | 2022-05-27 | 2022-05-27 | Generalized self-adaptive monopulse angle measurement method based on conformal array antenna |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115015846A CN115015846A (en) | 2022-09-06 |
| CN115015846B true CN115015846B (en) | 2024-07-30 |
Family
ID=83071844
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210588222.4A Active CN115015846B (en) | 2022-05-27 | 2022-05-27 | Generalized self-adaptive monopulse angle measurement method based on conformal array antenna |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115015846B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105223554A (en) * | 2015-09-18 | 2016-01-06 | 河海大学 | Based on the space-time adaptive Monopulse estimation method of Doppler's triple channel Combined Treatment |
| CN109946664A (en) * | 2019-03-06 | 2019-06-28 | 西安电子科技大学 | A kind of array radar target seeker Monopulse estimation method under major lobe suppression |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4912477A (en) * | 1988-11-18 | 1990-03-27 | Grumman Aerospace Corporation | Radar system for determining angular position utilizing a linear phased array antenna |
| JP5911331B2 (en) * | 2012-02-24 | 2016-04-27 | 三菱電機株式会社 | Monopulse angle measuring device and monopulse angle measuring method |
| CN114488027A (en) * | 2021-12-16 | 2022-05-13 | 西安电子科技大学 | Wave beam zero setting and widening method of conformal array antenna |
-
2022
- 2022-05-27 CN CN202210588222.4A patent/CN115015846B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105223554A (en) * | 2015-09-18 | 2016-01-06 | 河海大学 | Based on the space-time adaptive Monopulse estimation method of Doppler's triple channel Combined Treatment |
| CN109946664A (en) * | 2019-03-06 | 2019-06-28 | 西安电子科技大学 | A kind of array radar target seeker Monopulse estimation method under major lobe suppression |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115015846A (en) | 2022-09-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108508423B (en) | Subarray digital sum and difference monopulse angle measurement method based on special-shaped array | |
| CN109946664B (en) | Array radar seeker monopulse angle measurement method under main lobe interference | |
| CN103235292B (en) | Full-dimension and difference angle measurement method for zero setting conformal calibration of a planar phased array | |
| CN111624565B (en) | Multi-area joint beam tracking method for large conformal phased array system | |
| CN107390197B (en) | Radar self-adaption sum-difference beam angle measurement method based on feature space | |
| CN112949100B (en) | Main lobe interference resisting method for airborne radar | |
| CN106291541A (en) | MIMO radar array design methodology based on non-homogeneous Subarray partition | |
| CN110261826A (en) | A kind of coherent interference suppression method of null broadening | |
| CN111239677B (en) | Multi-beam passive monopulse angle measurement method based on digital array | |
| CN114488027A (en) | Wave beam zero setting and widening method of conformal array antenna | |
| CN106646388A (en) | MIMO radar anti-interference method based on nested array | |
| CN113884979A (en) | Robust adaptive beam forming method for interference plus noise covariance matrix reconstruction | |
| CN110208757B (en) | Steady self-adaptive beam forming method and device for inhibiting main lobe interference | |
| CN108490428B (en) | Dimensionality reduction sub-array phase ratio tracking angle measurement method for resisting main lobe interference | |
| CN113820653B (en) | Meter wave radar low elevation angle target DOA estimation method based on dynamic sum and difference wave beams | |
| CN113156380B (en) | Main lobe noise suppression interference self-adaptive suppression method based on transceiving mismatch processing | |
| CN112130139B (en) | Distributed full-coherent sparse linear array radar system optimization array deployment method | |
| CN114814739A (en) | Main lobe interference suppression method based on distributed FDA-MIMO radar | |
| CN115015846B (en) | Generalized self-adaptive monopulse angle measurement method based on conformal array antenna | |
| CN111257863B (en) | High-precision multipoint linear constraint self-adaptive monopulse direction finding method | |
| CN111693979B (en) | Digital array monopulse angle measurement method based on Taylor expansion | |
| CN111812607A (en) | Meter-wave MIMO radar low elevation angle estimation method based on beam space | |
| CN111551908A (en) | Method for reducing complexity of array element activation algorithm of phased array system | |
| CN112904297B (en) | Method for forming and estimating angle of split-dimension self-adaptive monopulse beam | |
| CN111585631A (en) | Beam forming method for improving transmission gain of distributed polarization sensitive array |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |