Small interferometer system phase calibration method and device

Abstract

The invention belongs to the technical field of interferometer signal processing, and particularly relates to a small interferometer system phase calibration method and device, and the method comprises the steps: S1, obtaining the signal frequency of a measured incoming wave signal, and searching a phase difference calibration table of different angle intervals of a calibration frequency point corresponding to the signal frequency; s2, calculating a phase difference data vector relative to a reference measurement phase by using the phase of the incoming wave signal measured by each receiving channel; s3, traversing the phase difference calibration table, and determining a standard phase difference data vector closest to the phase difference data vector in the phase difference calibration table; s4, estimating an azimuth angle interval and a pitch angle interval of the incoming wave signal; and S5, based on the longest baseline distance, determining an accurate angle in the azimuth angle interval and the pitch angle interval. According to the invention, the ambiguity resolution correctness of the interferometer direction-finding system is ensured, and the direction-finding precision of the interferometer direction-finding system is effectively improved.

Description

Technical Field

[0001] The present application belongs to the technical field of interferometer signal processing, and in particular relates to a phase calibration method and device for a small interferometer system. Background Art

[0002] In passive direction finding technology, interferometer systems are widely used in aviation, astronomy, military and other fields due to their advantages such as fast speed, high accuracy and good sensitivity. The interferometer direction finding system obtains the phase difference through the distance difference of the target wave signal reaching different antenna array elements, and determines the target direction by using the relationship that the phase difference is proportional to the target wave angle. Therefore, the measurement deviation of phase and frequency will directly affect the measurement accuracy of the target wave angle. With the development of digital frequency measurement receivers, the existing frequency measurement technology is sufficient to meet the frequency accuracy requirements of the interferometer direction finding system, so the phase measurement error will become the key to the interferometer direction finding accuracy.

[0003] In engineering, interferometer direction-finding systems generally use multi-channel receivers to measure signal phase differences. Due to the manufacturing process of components, cables and other equipment, different receiving channels have certain phase consistency deviations. In addition, due to the limitations of the platform used for small devices, the internal angle of the antenna is relatively crowded, resulting in a more sensitive phase error introduced by antenna covers made of different materials and processes. The reflection and refraction effects caused by the incoming signal penetrating the antenna cover from different angles to reach the antenna unit can also magnify the error, and even cause direction ambiguity in severe cases. Therefore, for small platform interferometer direction-finding systems, the selection of phase calibration methods is particularly important.

[0004] The current phase calibration methods are mainly external signal source method and internal automatic calibration method. The external signal source method uses an external radiation signal to input into the RF front end, and then generates phase data of different channels through the direction finding receiver, and then generates a phase difference data vector. Traversing all calibration frequency points can obtain a full-band phase difference data calibration table. This method is usually calibrated in the antenna normal direction. In practical applications, the measurement accuracy of the incident wave direction near the normal direction is good. However, when the angle of the incoming wave differs too much from the antenna normal, especially under small aperture restrictions, the phase measurement error caused by the incoming wave signals at different angles penetrating the antenna cover will increase significantly, and in severe cases, it may lead to direction finding errors. Unlike the external signal source method, the internal automatic calibration method uses an internal calibration source generated by a built-in frequency synthesis module. The calibration process does not pass through the antenna front end. Although it is less affected by the space environment, this method only compensates for the phase error of different channels and does not consider the phase error caused by the antenna cover.

[0005] Therefore, when performing phase calibration on small-aperture platform interferometer direction-finding systems of 200 mm and below, in addition to the phase error introduced by the inconsistency of the receiving channel, the phase measurement error caused by penetrating the antenna cover from different angles must also be carefully considered. Summary of the invention

[0006] In order to solve the above problems, the present application provides a phase calibration method and device for a small interferometer system, so as to expand the application capability of the interferometer direction finding system in miniaturized equipment and promote the development of interferometer direction finding technology.

[0007] The first aspect of the present application provides a phase calibration method for a small interferometer system, mainly comprising:

[0008] Step S1: Obtain the signal frequency of the measured incoming signal and find the calibration frequency point f corresponding to the signal frequency. k Phase difference calibration table for different angle intervals The phase difference calibration table The standard phase difference data vectors of different azimuth calibration points and different elevation calibration points are recorded in Where i is the azimuth calibration point number, j is the elevation calibration point number;

[0009] Step S2: Calculate the phase difference data vector relative to the reference measurement phase using the phase of the incoming wave signal measured by each receiving channel

[0010] Step S3: traverse the phase difference calibration table Determine the phase difference calibration table Center and phase difference data vector The closest standard phase difference data vector

[0011] Step S4: according to the closest standard phase difference data vector Determine the azimuth calibration point and the elevation calibration point, and then estimate the azimuth angle interval and the elevation angle interval where the incoming wave signal is located;

[0012] Step S5: Based on the phase difference data vector and the longest azimuth baseline distance to determine the precise azimuth angle within the azimuth angle interval. Similarly, based on the phase difference data vector The precise pitch angle within the pitch angle interval is determined by combining the longest pitch baseline distance.

[0013] Preferably, before step S1, the method further comprises constructing a phase difference calibration table by the following steps:

[0014] Step S11: Determine the longest baseline distance L in the azimuth direction of the antenna in the interferometer direction finding system az , and the longest baseline distance L in pitch direction el ;

[0015] Step S12: for incoming waves with different signal frequencies, determine the maximum unambiguous angle θ in the azimuth direction based on the wavelength of the incoming wave signal. maz The maximum unambiguous angle θ with the pitch direction mel ;

[0016] Step S13: according to the required azimuth angle measurement range θ az And the pitch angle range θ el , determine the azimuth fuzzy number M az and the pitch fuzzy number M el ;

[0017] Step S14: Determine whether the azimuth fuzzy number M is not less than az The number of azimuth calibration points N az , and determine whether the pitch fuzzy number M is not less than el The number of pitch calibration points N el ;

[0018] Step S15: for each calibration frequency point f corresponding to the signal frequency k Perform full-angle calibration. For each calibration frequency point, record and store the phase difference data vector of each receiving channel measured phase at different angles relative to the reference measured phase as the standard phase difference data vector. By the standard phase difference data vector Forming a phase difference calibration table

[0019] Preferably, step S11 further comprises calibrating the environment of the interferometer direction finding system in a microwave darkroom.

[0020] Preferably, step S3 further comprises: calculating the phase difference calibration table The standard phase difference data vectors and the measured phase difference data vectors The Euclidean distance of the standard phase difference data vector with the smallest Euclidean distance is determined as the closest standard phase difference data vector.

[0021] The second aspect of the present application provides a small interferometer system phase calibration device, mainly comprising:

[0022] The phase difference calibration table query module is used to obtain the signal frequency of the measured incoming wave signal and find the calibration frequency point f corresponding to the signal frequency. k Phase difference calibration table for different angle intervals The phase difference calibration table The standard phase difference data vectors of different azimuth calibration points and different elevation calibration points are recorded in Where i is the azimuth calibration point number, j is the elevation calibration point number;

[0023] The phase difference data vector calculation module is used to calculate the phase difference data vector relative to the reference measurement phase using the phase of the incoming wave signal measured by each receiving channel.

[0024] Standard phase difference data vector matching module, used to traverse the phase difference calibration table Determine the phase difference calibration table Center and phase difference data vector The closest standard phase difference data vector

[0025] Angle interval calculation module, used to calculate the angle interval according to the closest standard phase difference data vector Determine the azimuth calibration point and the elevation calibration point, and then estimate the azimuth angle interval and the elevation angle interval where the incoming wave signal is located;

[0026] Precise angle calculation module for phase difference data vector and the longest azimuth baseline distance to determine the precise azimuth angle within the azimuth angle interval. Similarly, based on the phase difference data vector The precise pitch angle within the pitch angle interval is determined by combining the longest pitch baseline distance.

[0027] Preferably, the phase difference calibration table query module includes a phase difference calibration table construction unit for constructing a phase difference calibration table The phase difference calibration table construction unit comprises:

[0028] The longest baseline distance determination subunit is used to determine the longest baseline distance L in the azimuth direction of the antenna in the interferometer direction finding system. az , and the longest baseline distance L in pitch direction el ;

[0029] The maximum unambiguous angle calculation subunit is used to determine the maximum unambiguous angle θ of the azimuth based on the wavelength of the incoming wave signal for the incoming waves with different signal frequencies. maz The maximum unambiguous angle θ with the pitch direction mel ;

[0030] The fuzzy number determination subunit is used to determine the azimuth angle range θ according to the requirements az And the pitch angle range θ el , determine the azimuth fuzzy number M az and the pitch fuzzy number M el ;

[0031] The calibration point determination subunit is used to determine the ambiguity number M not less than the azimuth direction. az The number of azimuth calibration points N az , and determine whether the pitch fuzzy number M is not less than elThe number of pitch calibration points N el ;

[0032] The full-angle calibration subunit is used to calibrate each frequency point f corresponding to the signal frequency. k Perform full-angle calibration. For each calibration frequency point, record and store the phase difference data vector of each receiving channel measured phase at different angles relative to the reference measured phase as the standard phase difference data vector. By the standard phase difference data vector Forming a phase difference calibration table

[0033] Preferably, the interferometer direction-finding system calibration environment is carried out in a microwave darkroom.

[0034] Preferably, the standard phase difference data vector matching module includes a Euclidean distance matching unit for respectively calculating the phase difference calibration table The standard phase difference data vectors and the measured phase difference data vectors The Euclidean distance of the standard phase difference data vector with the smallest Euclidean distance is determined as the closest standard phase difference data vector.

[0035] This application is aimed at the interferometer direction-finding system of small-aperture antenna arrays. In a darkroom environment, a standard radiation source is used to collect azimuth and elevation two-dimensional full-angle phase difference data for each calibration frequency point, generate a phase difference calibration table and save it in the system's internal storage space. In actual testing, the phase difference data vector of the incoming wave signal is calculated according to different channels, and the correlation method is used to find the closest phase difference data vector in combination with the signal frequency, thereby determining the angle range of the incoming wave signal, and then calculating the precise angle of the incoming wave signal through the longest baseline in the interferometer system.

[0036] The present application takes into account the angle information of the incoming wave signal, greatly reducing the relative phase error caused by the incoming wave signals at different angles penetrating the antenna cover, which not only ensures the correctness of the deambiguation of the interferometer direction finding system, but also effectively improves the direction finding accuracy of the interferometer direction finding system. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a flow chart of a preferred embodiment of a phase calibration method for a small interferometer system of the present application. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0039] The first aspect of the present application provides a phase calibration method for a small interferometer system, such as Figure 1 As shown, the method mainly includes:

[0040] Step S1: Obtain the signal frequency of the measured incoming signal and find the calibration frequency point f corresponding to the signal frequency. k Phase difference calibration table for different angle intervals The phase difference calibration table The standard phase difference data vectors of different azimuth calibration points and different elevation calibration points are recorded in Where i is the number of the azimuth calibration point, and j is the number of the elevation calibration point.

[0041] In step S1, the corresponding calibration frequency point f can be first found according to the actual signal frequency. k Phase difference calibration table Phase difference calibration table The phase difference calibration table includes multiple calibration frequency points f. k Corresponding to a phase difference calibration table . Each phase difference calibration table It is essentially a two-dimensional matrix, each element in the matrix is ​​a standard phase difference data vector Use the subscripts i, j, and f k Indicates the calibration frequency f k The data in the i-th row and j-th column of .

[0042] In some optional embodiments, before step S1, the phase difference calibration table is constructed by the following steps:

[0043] Step S11: Determine the longest baseline distance L in the azimuth direction of the antenna in the interferometer direction finding system az , and the longest baseline distance L in pitch direction el.

[0044] In step S11, firstly, the interferometer direction finding system is calibrated in a microwave darkroom, and then the antenna array form in the interferometer direction finding system is determined according to requirements, and the longest baseline distances in azimuth and elevation are determined.

[0045] Step S12: for incoming waves with different signal frequencies, determine the maximum unambiguous angle θ in the azimuth direction based on the wavelength of the incoming wave signal. maz The maximum unambiguous angle θ with the pitch direction mel .

[0046] In step S12, the maximum unambiguous angle θ in the azimuth is determined according to the following formula: maz :

[0047]

[0048] Among them, λ is the wavelength of the incoming wave signal, which has a corresponding relationship with the signal frequency. For example, for an incoming wave signal with a signal frequency of 15 GHz, assuming that its longest baseline distance in azimuth is L az is 100 mm. After calculation, the maximum unambiguous angle θ maz It is about ±5.7°. That is to say, the target angle measured by the direction finder within the range of ±5.7° is accurate, and when it exceeds this angle, the measured target angle is a fuzzy value.

[0049] Step S13: according to the required azimuth angle measurement range θ az And the pitch angle range θ el , determine the azimuth fuzzy number M az and the pitch fuzzy number M el .

[0050] In step S13, it is assumed that the maximum unambiguous angle θ in the azimuth direction is maz The maximum unambiguous angle θ with the pitch direction mel After calculation in step S12, they are all ±5.7°, while the required azimuth angle measurement range θ az And the pitch angle range θ el It is usually ±45° or ±60°, so the fuzzy number is 45 / 5.7 or 60 / 5.7, and then rounded up.

[0051] Step S14: Determine whether the azimuth fuzzy number M is not less than az The number of azimuth calibration points N az , and determine whether the pitch fuzzy number M is not less than el The number of pitch calibration points N el .

[0052] In step S14, in order to ensure that there is no phase ambiguity in direction finding, the number of calibration points in azimuth and elevation for each calibration frequency point should be greater than the corresponding ambiguity number, that is, the number of calibration points in azimuth direction N az >M az , the number of pitch calibration points N el >M el The angle value to be calibrated of the two-dimensional dot matrix of each calibration frequency point is determined in combination with the direction finding range.

[0053] Step S15: for each calibration frequency point f corresponding to the signal frequency k Perform full-angle calibration. For each calibration frequency point, record and store the phase difference data vector of each receiving channel measured phase at different angles relative to the reference measured phase as the standard phase difference data vector. By the standard phase difference data vector Forming a phase difference calibration table

[0054] In step S15, all calibration frequency points f0, f1, f2, ..., f m Perform full-angle calibration in sequence, where f0 is the minimum frequency point to be calibrated, f m is the maximum frequency to be calibrated, for example, 1GHz, 2GHz, 2GHz, 8GHz, 16GHz, etc., a total of m signal frequencies corresponding to the calibration frequency points. For each calibration frequency point, record and store the phase difference data vector of each receiving channel measurement phase relative to the reference measurement phase at different angles. Assume that for the kth calibration frequency point f k , which forms the phase difference calibration table Including N el Row, N az Column elements, each element is a standard phase difference data vector Where i and j correspond to the azimuth and elevation angles to be calibrated, respectively, as shown in the following matrix:

[0055]

[0056] For example, assuming that the azimuth angle measurement range and the elevation angle measurement range are both ±60°, with a total scanning range of 120°, the maximum unambiguous angle θ in azimuth is maz The maximum unambiguous angle θ with the pitch direction mel The scanning range is ±20°, and the total scanning range is 40°. The number of calibration points in azimuth and elevation is 3. Assuming that the number of calibration points in azimuth and elevation is 4, the phase difference calibration table is It is a 4*4 two-dimensional matrix, each calibration point covers a 30° scanning range, where It can represent the standard phase difference data vector between -60° and -30° in azimuth and -60° and -30° in elevation. It can represent the standard phase difference data vector between -60° and -30° in azimuth and -30° and 0° in elevation. It can represent the standard phase difference data vector between -30° and 0° in azimuth and -60° and -30° in elevation.

[0057] The database pre-stores the above m phase difference calibration tables That is, in actual use, a corresponding phase difference calibration table can be matched according to any measured signal frequency. In an alternative implementation, if there is an uncovered signal frequency in the database, the phase difference calibration table of the corresponding signal frequency can be obtained by matching the nearest adjacent signal frequency.

[0058] Step S2: Calculate the phase difference data vector relative to the reference measurement phase using the phase of the incoming wave signal measured by each receiving channel

[0059] Step S3: traverse the phase difference calibration table Determine the phase difference calibration table Center and phase difference data vector The closest standard phase difference data vector

[0060] This step is used to traverse the phase difference calibration table. All standard phase difference data vectors in the , use the correlation method to find the phase difference data vector with the measured phase difference data vector The closest standard phase difference data vector. In some optional embodiments, step S3 further includes: calculating the phase difference calibration table The standard phase difference data vectors and the measured phase difference data vectors The Euclidean distance of the standard phase difference data vector with the smallest Euclidean distance is determined as the closest standard phase difference data vector.

[0061] Still using the aforementioned 4*4 phase difference calibration table For example, assuming that the standard phase difference data vector The phase difference data vector with the actual measurement The Euclidean distance is the smallest, then the standard phase difference data vector Correct the phase of the incoming signal.

[0062] Step S4: according to the closest standard phase difference data vector The azimuth calibration point and the elevation calibration point are determined, and then the azimuth angle interval and the elevation angle interval of the incoming signal are estimated.

[0063] As described in step S3, the standard phase difference data vector It means that the azimuth angle range is between -30° and 0°, and the elevation angle range is also between -30° and 0°.

[0064] Step S5: Based on the phase difference data vector and the longest azimuth baseline distance to determine the precise azimuth angle within the azimuth angle interval. Similarly, based on the phase difference data vector The precise pitch angle within the pitch angle interval is determined by combining the longest pitch baseline distance.

[0065] In this step, the corresponding precise angle θ can be calculated according to the following formula:

[0066]

[0067] Where λ is the wavelength of the incoming signal, and L is the longest baseline distance, i.e. the longest baseline distance L in azimuth mentioned above. az , and the longest baseline distance L in pitch direction el , It is the phase difference data corresponding to the longest measured baseline. Due to the existence of phase ambiguity, the phase difference can be calculated into multiple specific angle values. Then, according to the azimuth angle interval and the elevation angle interval determined in step S4, the angle falling into the interval is determined to be the unambiguous and precise angle of the incoming signal.

[0068] The second aspect of the present application provides a small interferometer system phase calibration device corresponding to the above method, mainly comprising:

[0069] The phase difference calibration table query module is used to obtain the signal frequency of the measured incoming wave signal and find the calibration frequency point f corresponding to the signal frequency. k Phase difference calibration table for different angle intervals The phase difference calibration table The standard phase difference data vectors of different azimuth calibration points and different elevation calibration points are recorded in Where i is the azimuth calibration point number, j is the elevation calibration point number;

[0070] The phase difference data vector calculation module is used to calculate the phase difference data vector relative to the reference measurement phase using the phase of the incoming wave signal measured by each receiving channel.

[0071] Standard phase difference data vector matching module, used to traverse the phase difference calibration table Determine the phase difference calibration table Center and phase difference data vector The closest standard phase difference data vector

[0072] Angle interval calculation module, used to calculate the angle interval according to the closest standard phase difference data vector Determine the azimuth calibration point and the elevation calibration point, and then estimate the azimuth angle interval and the elevation angle interval where the incoming wave signal is located;

[0073] Precise angle calculation module for phase difference data vector and the longest azimuth baseline distance to determine the precise azimuth angle within the azimuth angle interval. Similarly, based on the phase difference data vector The precise pitch angle within the pitch angle interval is determined by combining the longest pitch baseline distance.

[0074] In some optional implementations, the phase difference calibration table query module includes a phase difference calibration table construction unit for constructing a phase difference calibration table. The phase difference calibration table construction unit comprises:

[0075] The longest baseline distance determination subunit is used to determine the longest baseline distance L in the azimuth direction of the antenna in the interferometer direction finding system. az , and the longest baseline distance L in pitch direction el ;

[0076] The maximum unambiguous angle calculation subunit is used to determine the maximum unambiguous angle θ of the azimuth based on the wavelength of the incoming wave signal for the incoming waves with different signal frequencies. maz The maximum unambiguous angle θ with the pitch direction mel ;

[0077] The fuzzy number determination subunit is used to determine the azimuth angle range θ according to the requirements az And the pitch angle range θ el , determine the azimuth fuzzy number M az and the pitch fuzzy number M el ;

[0078] The calibration point determination subunit is used to determine the ambiguity number M not less than the azimuth direction. az The number of azimuth calibration points N az , and determine whether the pitch fuzzy number M is not less than el The number of pitch calibration points N el ;

[0079] The full-angle calibration subunit is used to calibrate each frequency point f corresponding to the signal frequency. k Perform full-angle calibration. For each calibration frequency point, record and store the phase difference data vector of each receiving channel measured phase at different angles relative to the reference measured phase as the standard phase difference data vector. By the standard phase difference data vector Forming a phase difference calibration table

[0080] In some optional embodiments, the interferometer direction finding system calibration environment is carried out in a microwave darkroom.

[0081] In some optional embodiments, the standard phase difference data vector matching module includes a Euclidean distance matching unit for respectively calculating the phase difference calibration table The standard phase difference data vectors and the measured phase difference data vectors The Euclidean distance of the standard phase difference data vector with the smallest Euclidean distance is determined as the closest standard phase difference data vector.

[0082] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A phase calibration method for a small interferometer system, characterized in that: include: Step S1: Obtain the signal frequency of the measured incoming signal and find the calibration frequency point f corresponding to the signal frequency. k Phase difference calibration table for different angle intervals The phase difference calibration table The standard phase difference data vectors of different azimuth calibration points and different elevation calibration points are recorded in Where i is the azimuth calibration point number, j is the elevation calibration point number; Step S2: Calculate the phase difference data vector relative to the reference measurement phase using the phase of the incoming wave signal measured by each receiving channel Step S3: traverse the phase difference calibration table Determine the phase difference calibration table Center and phase difference data vector The closest standard phase difference data vector Step S4: according to the closest standard phase difference data vector Determine the azimuth calibration point and the elevation calibration point, and then estimate the azimuth angle interval and the elevation angle interval where the incoming wave signal is located; Step S5: Based on the phase difference data vector and the longest azimuth baseline distance to determine the precise azimuth angle within the azimuth angle interval. Similarly, based on the phase difference data vector The precise pitch angle within the pitch angle interval is determined by combining the longest pitch baseline distance.

2. The phase calibration method of a small interferometer system according to claim 1, characterized in that: Before step S1, the phase difference calibration table is constructed by the following steps: Step S11: Determine the longest baseline distance L in the azimuth direction of the antenna in the interferometer direction finding system az , and the longest baseline distance L in pitch direction el ; Step S12: for incoming waves with different signal frequencies, determine the maximum unambiguous angle θ in the azimuth direction based on the wavelength of the incoming wave signal. maz The maximum unambiguous angle θ with the pitch direction mel ; Step S13: according to the required azimuth angle measurement range θ az And the pitch angle range θ el , determine the azimuth fuzzy number M az and the pitch fuzzy number M el ; Step S14: Determine whether the azimuth fuzzy number M is not less than az The number of azimuth calibration points N az , and determine whether the pitch fuzzy number M is not less than el The number of pitch calibration points N el ; Step S15: for each calibration frequency point f corresponding to the signal frequency k Perform full-angle calibration. For each calibration frequency point, record and store the phase difference data vector of each receiving channel measured phase at different angles relative to the reference measured phase as the standard phase difference data vector. By the standard phase difference data vector Forming a phase difference calibration table 3. The phase calibration method of a small interferometer system as claimed in claim 2, characterized in that: Step S11 further includes calibrating the environment of the interferometer direction finding system in a microwave darkroom.

4. The phase calibration method of a small interferometer system according to claim 1, characterized in that: Step S3 further includes: calculating the phase difference calibration table The standard phase difference data vectors and the measured phase difference data vectors The Euclidean distance of the standard phase difference data vector with the smallest Euclidean distance is determined as the closest standard phase difference data vector.

5. A phase calibration device for a small interferometer system, characterized in that: include: The phase difference calibration table query module is used to obtain the signal frequency of the measured incoming wave signal and find the calibration frequency point f corresponding to the signal frequency. k Phase difference calibration table for different angle intervals The phase difference calibration table The standard phase difference data vectors of different azimuth calibration points and different elevation calibration points are recorded in Where i is the azimuth calibration point number, j is the elevation calibration point number; The phase difference data vector calculation module is used to calculate the phase difference data vector relative to the reference measurement phase using the phase of the incoming wave signal measured by each receiving channel. Standard phase difference data vector matching module, used to traverse the phase difference calibration table Determine the phase difference calibration table Center and phase difference data vector The closest standard phase difference data vector Angle interval calculation module, used to calculate the angle interval according to the closest standard phase difference data vector Determine the azimuth calibration point and the elevation calibration point, and then estimate the azimuth angle interval and the elevation angle interval where the incoming wave signal is located; Precise angle calculation module for phase difference data vector and the longest azimuth baseline distance to determine the precise azimuth angle within the azimuth angle interval. Similarly, based on the phase difference data vector The precise pitch angle within the pitch angle interval is determined by combining the longest pitch baseline distance.

6. The phase calibration device of a small interferometer system as claimed in claim 5, characterized in that: The phase difference calibration table query module includes a phase difference calibration table construction unit for constructing a phase difference calibration table. The phase difference calibration table construction unit comprises: The longest baseline distance determination subunit is used to determine the longest baseline distance L in the azimuth direction of the antenna in the interferometer direction finding system. az , and the longest baseline distance L in pitch direction el ; The maximum unambiguous angle calculation subunit is used to determine the maximum unambiguous angle θ of the azimuth based on the wavelength of the incoming wave signal for the incoming waves with different signal frequencies. maz The maximum unambiguous angle θ with the pitch direction mel ; The fuzzy number determination subunit is used to determine the azimuth angle range θ according to the requirements az And the pitch angle range θ el , determine the azimuth fuzzy number M az and the pitch fuzzy number M el ; The calibration point determination subunit is used to determine the ambiguity number M not less than the azimuth direction. az The number of azimuth calibration points N az , and determine whether the pitch fuzzy number M is not less than el The number of pitch calibration points N el ; The full-angle calibration subunit is used to calibrate each frequency point f corresponding to the signal frequency. k Perform full-angle calibration. For each calibration frequency point, record and store the phase difference data vector of each receiving channel measured phase at different angles relative to the reference measured phase as the standard phase difference data vector. By the standard phase difference data vector Forming a phase difference calibration table 7. The phase calibration device of a small interferometer system as claimed in claim 6, characterized in that: The interferometer direction finding system calibration environment is carried out in a microwave darkroom.

8. The phase calibration device of a small interferometer system as claimed in claim 5, characterized in that: The standard phase difference data vector matching module includes a Euclidean distance matching unit for calculating the phase difference calibration table The standard phase difference data vectors and the measured phase difference data vectors The Euclidean distance of the standard phase difference data vector with the smallest Euclidean distance is determined as the closest standard phase difference data vector.

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