CN115561783A - Anti-interference GNSS antenna real-time phase center change compensation method - Google Patents

Anti-interference GNSS antenna real-time phase center change compensation method Download PDF

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CN115561783A
CN115561783A CN202211107606.6A CN202211107606A CN115561783A CN 115561783 A CN115561783 A CN 115561783A CN 202211107606 A CN202211107606 A CN 202211107606A CN 115561783 A CN115561783 A CN 115561783A
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antenna
phase
phase center
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interference
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倪永华
董建明
杜梦杰
于晓磊
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CETC 54 Research Institute
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    • 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
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/21—Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
    • 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
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/23—Testing, monitoring, correcting or calibrating of receiver elements
    • 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
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/35—Constructional details or hardware or software details of the signal processing chain
    • G01S19/37—Hardware or software details of the signal processing chain

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Abstract

The invention discloses a method for compensating real-time phase center change of an anti-interference GNSS antenna, and belongs to the technical field of antennas. The method comprises the following steps: identifying an interfering signal direction; forming a virtual antenna using a power inversion method, thereby suppressing interference; for each satellite, calculating an instantaneous phase center of the virtual antenna; the phase center variation is compensated for, thereby obtaining a stable carrier phase center. The method of the invention does not need linear constraint, has no special requirements on the structure of the receiver, has higher calculation efficiency, can be realized in the environment with limited resources, and reduces the hardware cost of the high-precision anti-interference GNSS antenna.

Description

Anti-interference GNSS antenna real-time phase center change compensation method
Technical Field
The invention relates to a method for compensating real-time phase center change of an anti-interference GNSS antenna, and belongs to the technical field of antennas.
Background
An anti-jamming antenna is one of the most effective methods for suppressing the adverse effects of interfering signals in GNSS positioning. Most jammer resistant antennas can adaptively adjust the radiation coefficients of the antenna to minimize the jammer effect. Changing the radiation pattern will also cause the Antenna Phase Center (APC) to change accordingly. Meanwhile, the stable phase center is the premise of high-precision GNSS positioning, and anti-interference and high precision become the embarrassment of GNSS antenna design. The research provides an effective antenna phase center change (PCV) compensation algorithm for the anti-interference antenna, and the real-time high-precision application of the anti-interference antenna can be realized. The performance of the algorithm is evaluated by a short baseline test, and the result shows that the proposed algorithm can reduce the carrier phase residual error by compensating the anti-interference antenna PCV, so that the RTK positioning 3D Root Mean Square (RMS) is improved. After PCV correction, the RTK positioning precision of the anti-interference antenna is within 4 cm.
The vulnerability of satellite navigation signals is one of the major challenges facing Global Navigation Satellite Systems (GNSS). The main navigation anti-interference technology is that harmful interference signals are inhibited through a specially designed GNSS anti-interference antenna array, an adaptive array anti-interference antenna is a main part of a GNSS receiver for inhibiting the interference signals, and a radiation pattern of the antenna can be changed to inhibit signal interference. Excellent interference immunity has been achieved using antenna array technology. Interference rejection performance can be measured by the capability of the interference-to-signal ratio (JSR). One of the side effects of changing the antenna radiation pattern is that the phase center of the antenna is changed, which adversely affects the high-precision positioning of GNSS.
It can be seen that whether the carrier phase measurement can meet the requirement of high-precision application depends mainly on the disturbance amplitude and the phase center of the array elements of the symmetric antenna array adopting the Power Inversion (PI) algorithm. However, there is no relevant solution in the prior art.
Disclosure of Invention
In view of this, the invention provides a method for compensating the change of the real-time phase center of an anti-interference GNSS antenna, which does not require linear constraint, has no special requirements on the structure of a receiver, has high calculation efficiency, can be realized in an environment with limited resources, and reduces the hardware cost of the high-precision anti-interference GNSS antenna.
In order to achieve the purpose, the invention adopts the technical scheme that:
an anti-interference GNSS antenna real-time phase center change compensation method comprises the following steps:
step 1, identifying the direction of an interference signal;
step 2, forming a virtual antenna by using a power inversion method so as to suppress interference;
step 3, calculating the instantaneous phase center of the virtual antenna for each satellite;
and 4, compensating the phase center change so as to obtain a stable carrier phase center.
Furthermore, the virtual antenna is composed of a plurality of antenna array elements of the anti-interference GNSS antenna, the radiation pattern of the virtual antenna is changed by adjusting the weight of each antenna array element, and the difference value between the antenna phase center of the virtual antenna and the instantaneous phase center is the antenna phase center variation of the virtual antenna.
Further, the specific manner of step 2 is as follows:
for an array antenna with N elements, the signal received by the ith element is denoted as x i (t), the antenna array of the input signal is represented as a vector x (n) = [ x = [ (/) ] 1 (n)；x 2 (n)；…；x N (n)] T ；
Dynamically adjusting the weight of each array element by a power inversion method to change the radiation pattern of the virtual antenna; the weight value of the ith array element of the array antenna is represented as w i The weight of all array elements is w = [) 1 ,w 2 ,…,w N ] T (ii) a The output of the antenna array is represented as:
y(n)＝w T x(n)
y (n) is the output of the array antenna, and the superscript T represents the transpose of the matrix;
the optimization goal of the power inversion method is to minimize the output power of the adaptive array antenna;
and solving the constraint optimization problem by a Lagrange multiplier method to obtain the solution of the optimal weight vector.
Further, the specific manner of step 3 is as follows:
pair null antenna arrayModeling phase centers of the columns; the specific mode is that the phase center of one antenna array element is positioned at the origin O, and the navigation satellite signal S comes from the direction
Figure BDA0003842321170000021
Wherein θ and
Figure BDA0003842321170000022
pitch and azimuth, respectively, the carrier phase of the signal S at point O is represented as
Figure BDA0003842321170000023
For the multi-element N-element antenna array, all the elements are assumed to be installed on the same plane, and the element distances between the adjacent elements in the ox axis direction and the oy axis direction are respectively marked as dx and dy;
defining the antenna reference point as the geometric center of the antenna array, denoted as O (0,0,0), and far field phase as
Figure BDA0003842321170000024
The field phase error introduced by a far field-phase center is taken as a constant, and C is defined as the constant phase deviation in the direction of the satellite incident angle and is used for compensating the variation of the antenna phase center;
accurately estimating C; the specific mode is that the far-field wave is a spherical wave, given a sphere center O', the phase deviation near the satellite is approximate to C, and the constant deviation of the specific satellite is estimated from the point set; obtaining two-dimensional phase centers in the main lobe radiation directions of the xoy plane and the yoz plane, and respectively taking the average values of the two-dimensional phase centers as calculated phase centers; the point sets of the surrounding area of the far-field spherical surface are respectively set as the phase values
Figure BDA0003842321170000031
i =1,2, …, n, n is not less than 4; an observation equation is established and solved by a least squares estimator.
The invention has the beneficial effects that:
1. the invention can effectively compensate the phase center of the antenna array and compensate the phase error of the antenna array caused by radiation change in a real-time mode. After the phase error is compensated, the phase center of the anti-interference antenna can be kept stable.
2. Compared with the MVDR algorithm, the method of the invention does not need linear constraint, has no special requirement on the structure of the receiver, has higher calculation efficiency, can be realized in the environment with limited resources, and reduces the hardware cost of the high-precision anti-interference GNSS antenna.
Drawings
Fig. 1 is a schematic diagram illustrating the effect of antenna phase center shift on signal phase.
Fig. 2 is a schematic diagram of a two-dimensional array antenna model.
Detailed Description
A method for compensating real-time phase center change of an anti-interference GNSS antenna is used for compensating the phase center of an anti-interference GNSS antenna array. For GNSS positioning applications, the user's position may be determined by measuring the distance between GNSS satellites and the user's antenna via GNSS ranging signals. More specifically, "distance" refers to the distance between the satellite antenna phase center and the antenna phase center. The phase center of the design is stable with respect to the geometric center of the antenna, which is generally dependent on the design of the antenna. The antenna phase center of the present method is referred to as the Antenna Phase Center (APC). The carrier phase measured by a GNSS receiver is commonly referred to as the Instantaneous Phase Centre (IPC) and depends on the direction in which the signal comes. Due to imperfections in GNSS antenna implementations, the Instantaneous Phase Center (IPC) is usually different from the Antenna Phase Center (APC), and the difference between the Instantaneous Phase Center (IPC) and the Antenna Phase Center (APC) is referred to as the antenna Phase Center Variation (PCV). The Phase Center Variation (PCV) of the antenna varies from millimeter to meter depending on the antenna design. PCV effects depend on satellites, so large PCV values reduce positioning accuracy and are therefore always considered as error sources in GNSS precision positioning applications. For example, the PCV value of a geodetic grade GNSS antenna is typically less than a few millimeters.
A standard GNSS antenna does not change its radiation pattern and therefore its PCV value can be calibrated by long term observation. For an anti-jamming antenna, the receiving antenna comprises a plurality of independent antenna elements, the directional diagram can be adjusted according to the direction of the jamming signal, and therefore the PCV of the anti-jamming antenna also changes along with the change of the radiation diagram. It cannot be directly calibrated.
An anti-jamming GNSS antenna array is usually composed of a plurality of antenna elements. These antenna elements constitute a virtual antenna. The radiation pattern of the virtual antenna can then be changed by adjusting the weight of each antenna element. Of course, the whole anti-interference antenna is composed of two antenna elements. The phase centers (APC) of each antenna element are denoted OA and OB, and for satellite i, the Instantaneous Phase Centers (IPC) of the two antenna elements are denoted IA and IB. The virtual antenna formed is denoted as V. APC and IPC of the virtual antenna are recorded as OV and IV, and the difference value of OV and IV is PCV of the virtual antenna. Since the radiation pattern of the virtual antenna changes with the change of the interference signal, PCV also changes. In contrast to the jammer antenna, the PCV is compensated to eliminate the PCV error of the virtual antenna V.
The method comprises the following four steps:
step 1, identifying the direction of an interference signal;
step 2, forming a virtual antenna by using a power inversion method so as to suppress interference;
step 3, calculating the instantaneous phase center of the virtual antenna for each satellite;
and 4, compensating the phase center change so as to obtain a stable carrier phase center.
The first two steps are used for achieving an anti-interference function, and the last two steps are used for achieving PCV compensation of the antenna.
The anti-interference algorithm of the adaptive antenna array comprises the following steps: least Mean Square (LMS), recursive Least Squares (RLS), sampled covariance matrix inversion (SMI), uniform Linear Array (ULA), space-time adaptive processing (STAP), and the like. Different algorithms have different interference rejection capabilities and require different inputs.
In step 2, a Power Inversion (PI) algorithm is used to form null steering beam null interference, which does not need prior interference information. The principle of the PI algorithm can be described as follows:
for an array antenna with N elements, the first oneThe signals received by the i array elements are denoted as x i (t), the antenna array of the input signal can be represented as a vector, represented as x (n) = [ x ]) 1 (n)；x 2 (n)；…；x N (n)] T . The Power Inversion (PI) algorithm dynamically adjusts the weights of each array element to change the radiation pattern of the virtual antenna. The weight value of the ith array element of the array antenna is represented as w i Can be written as w = [ w ] 1 ；w 2 ；…；w N ] T . The output of the antenna array can be expressed as:
y(n)＝w T x(n)
y (n) is the output of the array antenna and the superscript T represents the transpose of the matrix.
The optimization goal of the Power Inversion (PI) algorithm is to minimize the output power of the adaptive array antenna.
Figure BDA0003842321170000051
To ensure that the weight vector is not a zero vector, a constraint w is set T s =1, where s denotes a reference vector, whose weight is always 1. For example, the first matrix cell may be the reference matrix cell, s = [1;0; …;0] T . Since the interfering signal is usually stronger than the real signal, the optimization aims to make the antenna pattern form a null in the direction of the interfering signal to suppress the adverse effects of the interfering signal. The stronger the interfering signal, the deeper the null. In the Power Inversion (PI) algorithm, the direction of the interference signal may be automatically determined, and thus no additional operation is required to calculate the direction of the interference signal.
Output power P of array antenna out Can be expressed as: p is out ＝E[|y(n)| 2 ]＝w T R xx w
Wherein R is xx ＝E[x(n)x T (n)]Is the autocorrelation matrix of the input vector x (n) and E represents the mathematical expectation. The constraint optimization problem can be solved using the lagrangian multiplier method. The lagrange function can be written as:
L(w)＝w T R xx w+γ(w T s-1)
where γ is the coefficient of the lagrange multiplier. Gradient obedience for a given Lagrangian function
Figure BDA0003842321170000052
The solution of the optimal weight vector is:
Figure BDA0003842321170000053
here, the first and second liquid crystal display panels are,
Figure BDA0003842321170000054
is the minimum output power.
For example, the beidou navigation satellite signal may be expressed as:
Figure BDA0003842321170000055
where i is the satellite number and a is the signal amplitude; c i (t) is a signal ranging code; d i (t) is a data code modulated on a signal ranging code; θ is the signal carrier frequency;
Figure BDA0003842321170000056
is the initial phase of the signal carrier. According to Euler' S equation, signal S i (t) can also be expressed as:
Figure BDA0003842321170000057
wherein M is i ＝aC i (t)D i (t) is the amplitude of the signal. Power Inversion (PI) algorithm making E [ | y (n) & gtnon calculation 2 ]And a minimum, where y (n) is the amplitude. It is clear that the Power Inversion (PI) algorithm only considers the amplitude of the signal M, and not S i Phase in (t)
Figure BDA0003842321170000058
A change in (c). When the interference signal is introduced, the weight value will be changed, and the phase position will be changed
Figure BDA0003842321170000059
Will follow the signal intensityThe change of degree, direction and the number of interference signals changes dynamically, thereby causing the phase of the signals to change. The distortion signal can be expressed as:
Figure BDA00038423211700000510
where H(s) is the amplitude of the GNSS signal,
Figure BDA00038423211700000511
is the distorted phase of the signal
Figure BDA00038423211700000512
Phi is the phase center error caused by the beamforming process.
The specific mode of the step 3 is as follows:
(1) Modeling of adaptive nulling antenna phase centers
Phase center errors are introduced during beamforming and vary dynamically with the interfering signal. On the other hand, precise positioning applications require a stable antenna phase center. Modeling the phase center error in the beamforming process to compensate for the phase center error in real time.
The first step is to model the phase center of the nulling antenna array. The effect of the phase center variation affects the measured signal phase. The geometrical relationship is shown in fig. 1. Given that the phase center of one antenna array element is positioned at the origin O, the navigation satellite signal S comes from the direction
Figure BDA0003842321170000061
Wherein θ and
Figure BDA0003842321170000062
pitch and azimuth angles, respectively. The carrier phase of the signal S at point O may be expressed as
Figure BDA0003842321170000063
If the phase center of an antenna element is shifted to O (x 0, y0, z 0), the observed phase can be expressed as:
Figure BDA0003842321170000064
if it is not
Figure BDA0003842321170000065
So | OP | = OO '. OP/| = OP | = OO'
According to the reciprocity theorem, the phase of the signal S relative to the phase center O' can be recorded as
Figure BDA0003842321170000066
Assuming that the far field radiation pattern function of the array antenna at the origin can be expressed as:
Figure BDA0003842321170000067
wherein
Figure BDA0003842321170000068
Is the actual amplitude value. Since | OP | is much smaller than
Figure BDA0003842321170000069
The amplitude value at O' can be approximated as
Figure BDA00038423211700000610
The far-field radiation pattern function may be expressed as:
Figure BDA00038423211700000611
for a multi-element N-element antenna array. It is assumed that all these units are mounted on the same plane. The cell pitch between adjacent cells in the ox-axis direction and the oy-axis direction is denoted as dx and dy, respectively. For a GNSS antenna array composed of N identical ideal elements, the antenna coordinate of any element is denoted as Fn (x) n ；y n ；z n ) N =1,2.., N, without considering the mutual coupling effect between array elements. If the adaptive algorithm does not work, its far-field Radiation Pattern Function (RPF) can be expressed as:
Figure BDA00038423211700000612
if the weight of the nth matrix element is w n (N =1,2.., N), the conjugate w of which is taken n Then the far field radiation pattern function of the array antenna using the adaptive algorithm can be expressed as:
Figure BDA0003842321170000071
a schematic diagram of a two-dimensional array antenna model is shown in fig. 2.
(2) Instantaneous phase center estimation
Defining an Antenna Reference Point (ARP) as the geometric center of the antenna array, and recording the geometric center as O (0,0,0), and recording the far-field phase influenced by the ARP as O (0,0,0)
Figure BDA0003842321170000072
Far field-phase center O' (x) 0 ,y 0 ,z 0 ) The introduced field phase error can be regarded as a constant and can be defined as:
Figure BDA0003842321170000073
where C is a constant phase deviation in the satellite incident angle direction, which can be used to compensate for the antenna Phase Center Variation (PCV).
The constant deviation C is accurately estimated. The far-field wave is a spherical wave, given the sphere center O', the phase deviation near the satellite can be approximated as C, the constant deviation for that particular satellite being estimated from the set of points. And obtaining two-dimensional phase centers in the main lobe radiation directions of the xoy plane and the yoz plane, and respectively taking the average values of the two-dimensional phase centers as calculated phase centers. The point set of the surrounding area of the far field sphere and the phase value are respectively set as
Figure BDA0003842321170000074
i =1,2, …, n, n ≧ 4. The observation equation can be expressed as:
Figure BDA0003842321170000075
for all points in the set, a set of equations is formed:
Figure BDA0003842321170000076
Figure BDA0003842321170000077
the observation equation can be simplified to a linear system: AX = y
The linear equation can be solved with a least squares estimator to yield: x = (A) T A) -1 A T y
The phase center (x 0, y0, z 0) is estimated and accordingly a phase center error compensation dOO 'r (in units of distance) is calculated, dOO' r/λ is over the entire number of cycles.
The specific mode of the step 4 is as follows:
(1) Compensation of PCV deviation
A position solution for the receiver is derived from the observation equation. The pseudorange and carrier phase observation equations for GNSS can be expressed as:
Figure BDA0003842321170000081
where Pi and Li are pseudorange and carrier phase measurements (in meters). ρ is the distance between the satellite antenna Phase Center Offset (PCO) and the receive antenna Phase Center Offset (PCO). c is the speed of light, δ t u And δ t S Are the user receiver clock error and the satellite clock error. Ii and T are the ionospheric delay and tropospheric delay, respectively, for the ith frequency. i and Ni are the wavelength and carrier phase ambiguity, ε, respectively, for the ith frequency ρ And ε φ Are pseudorange and carrier phase measurement noise. Delta PCV Is the phase error of the receive antenna array. For an anti-jamming antenna, the PCO of the receiving antenna is changed, so the change in PCO must be compensated for to meet the precise determinationThe bit requirement. In the method, δ can be calculated from the weighting factor and the satellite incident angle in the Power Inversion (PI) algorithm PCV Which are then compensated in pseudorange and carrier phase measurements. After PCV compensation, the anti-interference antenna virtually obtains a stable carrier phase center and the capability of supporting accurate positioning application. The PCV compensation algorithm is computationally efficient and therefore can be implemented in real time.
(2) Calculating the effect of interference on antenna Phase Center Variation (PCV)
The effect of phase variation in beamforming was examined by numerical simulation. In a 1 x 2 or 2 x 2 antenna array. Theoretically, a two-element antenna can generate a null, and a four-element antenna can resist interference signals in three different directions at most. Assuming that one or more interfering signals are present, weights are then calculated according to a Power Inversion (PI) algorithm. The radiation pattern is then changed and the phase distortion is examined to reveal the effects of the beamforming. The influence of interference on the Beidou B1I signal is checked, and the center frequency is 1561.098MHz. The array element spacing is half the signal wavelength, assuming the antenna array suffers from uncorrelated narrowband interference. The interference-to-signal ratio is 30dB.
(3) Antenna Phase Center Variation (PCV) compensation performance evaluation
Since the antenna PCV is mixed with other biases in GNSS measurements, it is difficult to directly and effectively isolate the antenna PCV. Short baseline RTK (real time kinematic carrier phase difference technology) data processing is used to isolate PCV deviations. For a short baseline RTK scenario, the double differential observations may be expressed as:
Figure BDA0003842321170000082
here, the first and second liquid crystal display panels are,
Figure BDA0003842321170000083
is the double difference operator. The equation shows that the short baseline RTK cancels most of the errors in GNSS observations, and the remaining biases are the double differential geometry distance, antenna Phase Center Variation (PCV) bias, double differential carrier phase ambiguity, andreceiver noise. For a typical earth-measuring GNSS antenna, the PCV bias is small, typically in the millimeter range, but for an anti-jamming antenna it becomes non-negligible. Geometric terms may be further removed if the Antenna Phase Centers (APCs) of the reference and rover antennas are precisely known. The carrier phase measurement has millimeter-scale measurement noise which can be ignored. Although the true value of the double differential carrier phase ambiguity is unknown, it is given as an integer constant unless cycle slip occurs. If the carrier phase ambiguity is correctly fixed to the correct integer, the remaining offset may be considered as a double differential PCV offset. The PCV effect of the reference antenna is negligible because the geodetic GNSS antenna has a fairly stable PCV. Thus, the residual offset in the double-differential observation can be considered as a single-differential PCV offset from the anti-jamming antenna.

Claims (4)

1. An anti-interference GNSS antenna real-time phase center change compensation method is characterized by comprising the following steps:
step 1, identifying the direction of an interference signal;
step 2, forming a virtual antenna by using a power inversion method so as to suppress interference;
step 3, calculating the instantaneous phase center of the virtual antenna for each satellite;
and 4, compensating the phase center change so as to obtain a stable carrier phase center.
2. The method as claimed in claim 1, wherein the virtual antenna comprises a plurality of antenna elements of the anti-GNSS jamming antenna, the radiation pattern of the virtual antenna is changed by adjusting the weight of each antenna element, and the difference between the antenna phase center of the virtual antenna and the instantaneous phase center is the amount of change in the antenna phase center of the virtual antenna.
3. The method according to claim 1, wherein the step 2 is specifically performed by:
for an array antenna with N elements, the signal received by the ith element is denoted as x i (t), the antenna array of the input signal is represented as a vector x (n) = [ x = [ (/) ] 1 (n)；x 2 (n)；…；x N (n)] T ；
Dynamically adjusting the weight of each array element by a power inversion method to change the radiation pattern of the virtual antenna; the weight value of the ith array element of the array antenna is represented as w i The weight of all array elements is w = [) 1 ,w 2 ,…,w N ] T (ii) a The output of the antenna array is represented as:
y(n)＝w T x(n)
y (n) is the output of the array antenna, and the superscript T represents the transpose of the matrix;
the optimization goal of the power inversion method is to minimize the output power of the adaptive array antenna;
and solving the constraint optimization problem by a Lagrange multiplier method to obtain the solution of the optimal weight vector.
4. The method according to claim 1, wherein the step 3 is specifically performed by:
modeling a phase center of the nulling antenna array; the specific mode is that the phase center of one antenna array element is positioned at the origin O, and the navigation satellite signal S comes from the direction
Figure FDA0003842321160000011
Wherein θ and
Figure FDA0003842321160000012
pitch and azimuth, respectively, the carrier phase of the signal S at point O is represented as
Figure FDA0003842321160000013
For the multi-element N-element antenna array, all the elements are assumed to be installed on the same plane, and the element distances between the adjacent elements in the ox axis direction and the oy axis direction are respectively marked as dx and dy;
defining the antenna reference point as the geometric center of the antenna array, denoted as O (0,0,0), and far field phase as
Figure FDA0003842321160000021
The field phase error introduced by a far field-phase center is taken as a constant, and C is defined as the constant phase deviation in the direction of the satellite incident angle and is used for compensating the variation of the antenna phase center;
accurately estimating C; the specific mode is that the far-field wave is a spherical wave, given a sphere center O', the phase deviation near the satellite is approximate to C, and the constant deviation of the specific satellite is estimated from the point set; obtaining two-dimensional phase centers in the main lobe radiation directions of the xoy plane and the yoz plane, and respectively taking the average values of the two-dimensional phase centers as calculated phase centers; setting the point set of the surrounding area of the far-field spherical surface and the phase value as
Figure FDA0003842321160000022
n is more than or equal to 4; an observation equation is established and solved by a least squares estimator.
CN202211107606.6A 2022-09-13 2022-09-13 Anti-interference GNSS antenna real-time phase center change compensation method Pending CN115561783A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116953746A (en) * 2023-09-21 2023-10-27 北京李龚导航科技有限公司 Method and device for orienting satellite navigation antenna based on single phase distortion
CN117452465A (en) * 2023-12-26 2024-01-26 中国测绘科学研究院 Sea surface multi-GNSS antenna and sonar combined positioning method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116953746A (en) * 2023-09-21 2023-10-27 北京李龚导航科技有限公司 Method and device for orienting satellite navigation antenna based on single phase distortion
CN116953746B (en) * 2023-09-21 2023-12-22 北京李龚导航科技有限公司 Method and device for orienting satellite navigation antenna based on single phase distortion
CN117452465A (en) * 2023-12-26 2024-01-26 中国测绘科学研究院 Sea surface multi-GNSS antenna and sonar combined positioning method
CN117452465B (en) * 2023-12-26 2024-02-23 中国测绘科学研究院 Sea surface multi-GNSS antenna and sonar combined positioning method

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