Phase interferometer direction finding disambiguation method, computer device and readable storage medium

Abstract

The application provides a phase-interferometer direction-finding ambiguity resolution method, a computer device and a readable storage medium, and the method comprises the following steps: determining a phase period multiple value range corresponding to a shortest baseline according to the length of the shortest baseline in the interferometer and the effective direction-finding range of the interferometer; constructing an error vector of a real phase difference vector projected on a target vector; solving a phase period multiple vector capable of minimizing the error vector according to a vector relationship equation of the target vector, the real phase difference vector and the error vector; traversing each value in the phase period multiple value range corresponding to the shortest baseline, calculating a corresponding phase period multiple vector, and calculating the modulus of the error vector; and taking the phase period multiple vector corresponding to the minimum modulus of the error vector as an output result. According to the model of the application, the amount of calculation is small, and the calculation efficiency is high.

Description

Technical Field

[0001] This invention relates to the field of phase interferometer deambiguation technology, and more specifically, to a phase interferometer direction finding deambiguation method, computer equipment, and readable storage medium. Background Technology

[0002] Phase interferometers offer high angular measurement accuracy and are widely used in military and civilian fields such as navigation, passive detection, and aerospace. Phase interferometers are a relatively mature technology. They utilize the difference in the path length of electromagnetic waves incident from the same far-field radiation source to different antenna array elements in space, resulting in different phases received by each direction-finding element. This phase difference is related to the incident angle of the electromagnetic wave beam; measuring this phase difference determines the direction of arrival. The direction-finding accuracy of the interferometer is related to the baseline length (distance between antenna array elements), the electromagnetic wave frequency, and the incident angle. For the antenna array itself, a longer baseline length results in higher direction-finding accuracy, and there is extensive and mature research on this topic.

[0003] Interferometer direction finding suffers from phase ambiguity. Various methods exist for deambiguity resolution in engineering applications, such as long / short baseline methods, high / low frequency methods, single-pulse angle measurement, distance measurement, baseline rotation, and frequency modulation. Among these, multi-baseline deambiguity resolution is the most widely used.

[0004] However, judging from publicly available papers and published patents, existing defuzzification methods, whether traditional stepwise defuzzification or multidimensional search of staggered baselines, involve excessive computation and time consumption, thus affecting direction finding efficiency. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems in the prior art where the defuzzification method has too much computational load, too long time consumption, and affects the direction finding efficiency.

[0006] Therefore, the first aspect of the present invention provides a method for unambiguous direction finding using a phase interferometer.

[0007] A second aspect of the present invention provides a computer device.

[0008] A third aspect of the present invention provides a computer-readable storage medium.

[0009] This invention provides a method for unambiguous direction finding using a phase interferometer, comprising:

[0010] Based on the length of the shortest baseline in the interferometer and the effective direction finding range of the interferometer, the range of values ​​for the phase period multiple corresponding to the shortest baseline is determined; whereby the phase period multiple is used to represent the possibility that the phase difference in engineering measurement lags or leads the actual phase difference by more than one cycle of electromagnetic wave vibration.

[0011] The column vector formed by the phase period multiples corresponding to the n baselines in the interferometer is defined as the phase period multiple vector, the column vector formed by the true phase difference corresponding to the n baselines is defined as the true phase difference vector, and the column vector formed by the phase lag caused by the lengths of the n baselines is defined as the target vector. An error vector is constructed by projecting the true phase difference vector onto the target vector, where the error vector is the difference between the projection vector of the true phase difference vector onto the target vector and the phase period multiple vector.

[0012] Based on the vector relationship equation between the target vector, the true phase difference vector, and the error vector, the phase period multiple vector that minimizes the magnitude of the error vector is solved. Specifically, the vector relationship equation is differentiated step by step, and the magnitude of the error vector is minimized when the derivative is 0. The values ​​of all elements in the phase period multiple vector are calculated based on the phase period multiple value corresponding to the shortest baseline and the true phase difference corresponding to the shortest baseline.

[0013] Iterate through each value in the range of phase period multiples corresponding to the shortest baseline, calculate the corresponding phase period multiple vector, and calculate the magnitude of the error vector. The phase period multiple vector corresponding to the smallest magnitude of the error vector is taken as the output result.

[0014] According to the above-described phase interferometer direction finding and deambiguation method of the present invention, it may further have the following additional technical features:

[0015] In the above technical solution, determining the range of phase period multiple values ​​corresponding to the shortest baseline based on the length of the shortest baseline in the interferometer and the effective direction finding range of the interferometer includes:

[0016]

[0017] Where TraAngle represents the effective unidirectional direction finding range, Ceil represents the rounding up algorithm, l1 represents the length of the shortest baseline, λ represents the wavelength of the incident signal, and C1(max) represents the maximum value of the phase period multiple corresponding to the shortest baseline. The phase period multiple C1 corresponding to the shortest baseline has 2C1(max)+1 values, which are integers in the range of -C1(max) to C1(max).

[0018] In the above technical solution, the engineering measurement phase difference and the true phase difference have the following relationship:

[0019]

[0020] in, This represents the actual phase difference between antenna elements. This represents the phase difference in engineering measurements, where C represents the phase period multiple.

[0021] The actual phase difference and the baseline length have the following relationship:

[0022]

[0023] Where l represents the distance between the two antennas, i.e., the baseline length; θ represents the angle between the incident signal and the interferometer's line of sight.

[0024] In the above technical solution, for n baselines, the following system of equations exists:

[0025]

[0026] Converting this system of equations into column vector form, we have:

[0027] Φ+2πC=LΘ

[0028] Among them, the phase difference vector of engineering measurement Phase period multiple vector C = [C1…C n ] T The angle vector Θ between the incident signal and the interferometer's line of sight is Θ = [sinθ1…sinθ] n ] T L is a diagonal matrix:

[0029] In the above technical solution, the angle vector Θ between the incident signal and the interferometer's line of sight is simplified to sinθ, which is closest to the true value, resulting in the rewritten vector equation:

[0030] Φ′=Dsinθ

[0031] Where Φ′ represents the true phase difference vector, and D represents the target vector.

[0032] In the above technical solution, the target vector, the true phase difference vector, the error vector, and the projection vector have the following relationship:

[0033] E=P-Φ′

[0034]

[0035] The vector relationship equation is then:

[0036]

[0037] Where E is the error vector and P is the projection vector of the true phase difference vector onto the target vector.

[0038] In the above technical solution, the method for finding the phase period multiple vector that minimizes the magnitude of the error vector includes:

[0039] Taking the derivative of the vector relation equation, when the derivative of the vector relation equation is 0, that is, when the magnitude of the error vector is minimum, then we have:

[0040]

[0041] Where D1,……,D n-1 D n These are elements in the target vector D;

[0042]

[0043] Where, round represents taking the nearest integer value, for Perform step-by-step calculations, and then calculate C2, C3...C n This yields the complete phase period multiple vector.

[0044] In the above technical solution, the elements in the target vector, the true phase difference vector, the error vector, and the phase period multiple vector are sorted in ascending order according to the length of the corresponding baseline.

[0045] The present invention also provides a computer device, the computer device including a processor and a memory, the memory storing a computer program, the computer program being loaded and executed by the processor to implement the phase interferometer direction finding deambiguity method as described in any of the above technical solutions.

[0046] The present invention also provides a computer-readable storage medium storing a computer program, which is loaded and executed by a processor to implement the phase interferometer direction finding deambiguity method as described in any of the above technical solutions.

[0047] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of the present invention are:

[0048] This invention addresses the widely used phase interferometer by providing a vector-based mathematical model for interferometry direction finding. This model is simple in form, easy to understand, and includes as much direction finding information as possible from the interferometer system. Based on this, the invention explains that the essence of the phase ambiguity problem lies in the uncertainty of the C vector, and derives a new deambiguity algorithm by assuming an error vector.

[0049] Compared with the original phase interferometer direction finding deambiguity algorithm, this invention has the following significant differences:

[0050] This invention offers a novel approach to unambiguous direction finding using phase interferometers, employing a spatial geometry method that is easy to understand and promote.

[0051] The defuzzing work carried out according to the model of this invention has a small computational load. Theoretically, as long as the minimum baseline is designed to be small enough, the direct calculation only increases once for each additional baseline. However, existing literature or engineering applications often use enumeration or statistical methods. When the number of baselines increases, the computational load of the original methods becomes unacceptable.

[0052] The defuzzing method provided by this invention is highly versatile and facilitates system upgrades and modifications.

[0053] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0054] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0055] Figure 1 This is a schematic diagram of a single-baseline interferometer direction finding in one embodiment of the present invention;

[0056] Figure 2 This is a schematic diagram of error vector construction in a phase interferometer direction finding and deambiguation method according to an embodiment of the present invention;

[0057] Figure 3 This is a flowchart of a phase interferometer direction finding and deambiguation method according to an embodiment of the present invention. Detailed Implementation

[0058] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0059] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0060] The following reference Figures 1 to 3 This describes a phase interferometer direction finding and deambiguation method provided according to some embodiments of the present invention.

[0061] Some embodiments of this application provide a method for direction finding and deambiguation using a phase interferometer.

[0062] like Figures 1 to 3As shown, the first embodiment of the present invention proposes a phase interferometer direction finding deambiguity method, which includes several parts: determining the range of values ​​of the phase period multiple corresponding to the shortest baseline, establishing a mathematical model, solving the vector relationship equation, and determining the final phase period multiple vector calculation result.

[0063] Determining the range of values ​​for the phase period multiple corresponding to the shortest baseline involves: based on the length of the shortest baseline in the interferometer and the effective direction-finding range of the interferometer, determining the range of values ​​for the phase period multiple corresponding to the shortest baseline; where the phase period multiple represents the probability that the phase difference in engineering measurements lags or leads the true phase difference by more than one cycle (2π) of electromagnetic wave vibration. Specifically, the purpose of a short baseline in interferometer system design is to resolve ambiguities, especially the shortest baseline, which is particularly important. Moreover, the path difference of the received electromagnetic waves in the interferometer system is limited by the effective direction-finding range of the interferometer. This indicates that the phase period multiple C1 corresponding to the shortest baseline can be determined during interferometer design and can only take a few values ​​such as -1, 0, and 1.

[0064] In some embodiments, determining the range of phase period multiples corresponding to the shortest baseline based on the length of the shortest baseline in the interferometer and the effective direction-finding range of the interferometer includes:

[0065]

[0066] Where TraAngle represents the effective unidirectional direction finding range, which is generally 45° in an interferometer system; Ceil represents the rounding up algorithm; l1 represents the length of the shortest baseline; λ represents the wavelength of the incident signal; and C1(max) represents the maximum value of the phase period multiple corresponding to the shortest baseline. The phase period multiple C1 corresponding to the shortest baseline has 2C1(max)+1 values, which are integers in the range of -C1(max) to C1(max).

[0067] The mathematical model is established by defining the column vector formed by the phase period multiples corresponding to the n baselines in the interferometer as the phase period multiple vector, defining the column vector formed by the true phase difference corresponding to the n baselines as the true phase difference vector, defining the column vector formed by the phase lag caused by the lengths of the n baselines as the target vector, and constructing an error vector projecting the true phase difference vector onto the target vector. The error vector is the difference between the projection vector of the true phase difference vector onto the target vector and the phase period multiple vector.

[0068] Specifically, the measured phase difference and the true phase difference have the following relationship:

[0069]

[0070] in, This represents the actual phase difference between antenna elements. It can fully reflect the path difference of the incident signal; This represents the phase difference in engineering measurements, where C represents the phase period multiple.

[0071] like Figure 1 In the one-dimensional single-baseline interferometer direction finding system shown, the true phase difference has the following relationship with the baseline length:

[0072]

[0073] Where l represents the distance between the two antennas, i.e., the baseline length; θ represents the angle between the incident signal and the interferometer's line of sight.

[0074] Combining the above two equations, we have:

[0075]

[0076] For n baselines, the following system of equations holds:

[0077]

[0078] Converting this system of equations into column vector form, we have:

[0079] Φ+2πC=LΘ

[0080] Among them, the phase difference vector of engineering measurement Phase period multiple vector C = [C1…C n ] T The angle vector Θ between the incident signal and the interferometer's line of sight is Θ = [sinθ1…sinθ] n ] T L is a diagonal matrix:

[0081] use The above formula can be further simplified to:

[0082] Φ′=LΘ

[0083] The above formula contains the physical information of a one-dimensional interferometer direction-finding system.

[0084] In some embodiments, for ease of analysis, the elements in the target vector, true phase difference vector, error vector, and phase period multiple vector are sorted in ascending order according to the length of the corresponding baseline; or according to... The values ​​are sorted from smallest to largest. Due to engineering errors, Θ here is a column vector; in reality, we only need a sinθ that is closest to the true value.

[0085] Specifically, the angle vector Θ between the incident signal and the interferometer's line of sight is simplified to sinθ, which is closest to the true value, resulting in the rewritten vector equation:

[0086] Φ′=sinθ

[0087] Where Φ′ represents the true phase difference vector, and D represents the target vector.

[0088] Since the longer the baseline, the higher the direction finding accuracy, the sinθ closest to the true value must be obtained from one or more measurements of the phase difference of the longest baseline or the longest baseline group.

[0089] The essence of phase ambiguity lies in the inherent uncertainty of the C vector in the above equation. Therefore, the process of phase deambiguity resolution involves calculating the C vector. The core idea of ​​this disclosure is to transform the calculation of the C vector into finding an error vector E with the smallest magnitude, based on knowledge of vector geometry. Figure 2 As shown. In Figure 2 In the vector space, an error vector E is constructed by projecting the vector Φ′ onto the target vector D.

[0090] Specifically, the target vector D, the true phase difference vector Φ′, the error vector E, and the projection vector P have the following relationship:

[0091] E=P-Φ′

[0092]

[0093] Therefore, the final solution to the fuzzy problem becomes the following mathematical problem: There exists an integer vector C such that:

[0094]

[0095] Where E is the error vector and P is the projection vector of the true phase difference vector onto the target vector, this equation is defined as a vector relation equation. While it's easy to understand how to solve |E| by enumerating all possible C vectors, this approach is impractical in engineering due to the enormous computational load and increased resource consumption. Therefore, this embodiment proposes a new method for solving the vector relation equation.

[0096] In some embodiments, solving the vector relationship equation includes: based on the vector relationship equation of the target vector, the true phase difference vector, and the error vector, solving for the phase period multiple vector that minimizes the magnitude of the error vector; wherein, the vector relationship equation is differentiated step by step, and when its derivative is 0, the magnitude of the error vector is minimized, and the values ​​of all elements in the phase period multiple vector are calculated based on the phase period multiple value corresponding to the shortest baseline and the true phase difference corresponding to the shortest baseline;

[0097] Specifically, in each specific C1 and Under guidance, the mathematical problem of vector relation equations was transformed into: In Under the given conditions, there exists a vector C such that the magnitude of the error vector E is minimized.

[0098] In one specific embodiment, the method for finding the phase period multiple vector that minimizes the magnitude of the error vector includes:

[0099] By taking the derivative of the vector relation equation step by step, when the derivative of the vector relation equation is 0, that is, when the magnitude of the error vector is minimum, then we have:

[0100]

[0101] Where D1,……,D n-1 D n These are elements in the target vector D;

[0102] The above system of equations can also be simplified as:

[0103]

[0104] Here, dot refers to the dot product of vectors. D n-1 These are vectors consisting of the first n-1 elements of vectors Φ′ and D, respectively.

[0105] Understandably, due to C1 and Given, we can calculate sequentially. Seek Then, the method for calculating each element in vector C is as follows:

[0106]

[0107] Where, round represents taking the nearest integer value, for Perform step-by-step calculations, and then calculate C2, C3...C n This yields the complete phase period multiple vector C.

[0108] The above method can determine the phase period multiple vector C under a specific value of C1. However, since C1 has multiple values, in determining the final phase period multiple vector calculation result, the process iterates through each value in the range of phase period multiple values ​​corresponding to the shortest baseline, calculates the corresponding phase period multiple vector C, and calculates the modulus |E| of the error vector. The phase period multiple vector corresponding to the minimum modulus |E| of the error vector is taken as the output result. The specific process is as follows: Figure 3 As shown.

[0109] In one specific embodiment, to verify the effectiveness of this method, 15 sets of data collected in a certain reconnaissance system were used to perform defuzzification work using the defuzzification algorithm provided by this method and the traditional enumeration method. The comparison results are shown in the table below.

[0110]

[0111]

[0112] The value of the longest baseline C4 in the table above is the final defuzzification result. It can be seen that the C4 value obtained by the defuzzification algorithm in this disclosure is consistent with the traditional enumeration method. Although there are errors in simulation time, it can be seen that the vector method defuzzification of this disclosure saves nearly an order of magnitude of time compared to the traditional enumeration method. Furthermore, the algorithm of this disclosure obtains more comprehensive information, not only calculating the entire C vector but also simultaneously calculating the minimum error vector magnitude, which can be used as a relative evaluation value of data quality.

[0113] A second embodiment of the present invention provides a computer device, the computer device including a processor and a memory, the memory storing a computer program, the computer program being loaded and executed by the processor to implement the phase interferometer direction finding deambiguity method as described in any of the above embodiments.

[0114] A third embodiment of the present invention provides a computer-readable storage medium storing a computer program that is loaded and executed by a processor to implement the phase interferometer direction finding deambiguity method as described in any of the above embodiments.

[0115] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0116] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A method for unambiguous direction finding using a phase interferometer, characterized in that, include: Based on the length of the shortest baseline in the interferometer and the effective direction finding range of the interferometer, determine the range of values ​​for the phase period multiple corresponding to the shortest baseline; The column vector formed by the phase period multiples corresponding to the n baselines in the interferometer is defined as the phase period multiple vector, the column vector formed by the true phase difference corresponding to the n baselines is defined as the true phase difference vector, and the column vector formed by the phase lag caused by the lengths of the n baselines is defined as the target vector. An error vector is constructed by projecting the true phase difference vector onto the target vector, where the error vector is the difference between the projection vector of the true phase difference vector onto the target vector and the phase period multiple vector. Based on the vector relationship equation between the target vector, the true phase difference vector, and the error vector, the phase period multiple vector that minimizes the magnitude of the error vector is solved. Specifically, the vector relationship equation is differentiated step by step, and the magnitude of the error vector is minimized when the derivative is 0. The values ​​of all elements in the phase period multiple vector are calculated based on the phase period multiple value corresponding to the shortest baseline and the true phase difference corresponding to the shortest baseline. Iterate through each value in the range of phase period multiples corresponding to the shortest baseline, calculate the corresponding phase period multiple vector, and calculate the magnitude of the error vector. The phase period multiple vector corresponding to the smallest magnitude of the error vector is taken as the output result. The process of determining the range of phase period multiples corresponding to the shortest baseline based on the length of the shortest baseline in the interferometer and the effective direction-finding range of the interferometer includes: = in, This indicates the effective unidirectional direction finding range; Ceil represents the rounding up algorithm. Indicates the length of the shortest baseline. Indicates the wavelength of the incident signal. This represents the maximum value of the phase period multiple corresponding to the shortest baseline. There are 2 Each value can be selected, and the value is... ~ Integers within the range; The phase difference measured in engineering measurements has the following relationship with the true phase difference: in, This represents the actual phase difference between antenna elements. Indicates the phase difference in engineering measurements. Indicates a multiple of the phase period; The actual phase difference and the baseline length have the following relationship: in, This indicates the distance between the two antennas, i.e., the baseline length; This indicates the angle between the incident signal and the interferometer's line of sight.

2. The method for unambiguous direction finding using a phase interferometer according to claim 1, characterized in that, For n baselines, the following system of equations holds: Converting this system of equations into column vector form, we have: Among them, the phase difference vector of engineering measurement Phase period multiple vector The angle vector between the incident signal and the interferometer's line of sight L is a diagonal matrix: .

3. The method for unambiguous direction finding using a phase interferometer according to claim 2, characterized in that, The angle vector between the incident signal and the interferometer's line of sight Simplify to the closest to the truth value The rewritten vector equation is obtained as follows: in, Let represent the true phase difference vector, and D represent the target vector. .

4. The method for unambiguous direction finding using a phase interferometer according to claim 3, characterized in that, The target vector, the true phase difference vector, the error vector, and the projection vector have the following relationship: The vector relationship equation is then: Where E is the error vector and P is the projection vector of the true phase difference vector onto the target vector.

5. The method for unambiguous direction finding using a phase interferometer according to claim 4, characterized in that, The methods for finding the phase period multiple vector that minimizes the magnitude of the error vector include: Taking the derivative of the vector relation equation, when the derivative of the vector relation equation is 0, that is, when the magnitude of the error vector is minimum, then we have: in, These are elements in the target vector D; Where, round represents taking the nearest integer value, for , ... Perform step-by-step calculations, and then calculate... , ... This yields the complete phase period multiple vector.

6. The method for unambiguous direction finding using a phase interferometer according to claim 1, characterized in that, The elements in the target vector, true phase difference vector, error vector, and phase period multiple vector are sorted in ascending order according to the length of the corresponding baseline.

7. A computer device, characterized in that, The computer device includes a processor and a memory, the memory storing a computer program that is loaded and executed by the processor to implement the phase interferometer direction finding deambiguity method as described in any one of claims 1 to 6.

8. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which is loaded and executed by a processor to implement the phase interferometer direction finding deambiguity method as described in any one of claims 1 to 6.

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