Method and device for measuring calibration parameters of array antenna

Abstract

The invention provides a method and a device for measuring calibration parameters of an array antenna. The method comprises the following steps of: performing grid division on a measurement space of the array antenna; determining the satellite density in each elevation angle layer of the measurement space after grid division in the current rotation period, and determining the weight coefficient of each elevation angle layer in the current rotation period based on the satellite density; wherein the weight coefficient is used for representing the satellite coverage priority of each elevation angle layer; based on the weight coefficient, determining a coverage score of each candidate angle; wherein the coverage score of the candidate angle is used for representing satellite coverage earnings after rotation of the array antenna according to the candidate angle in the current rotation period; determining a target rotation angle of the current rotation period based on the coverage score of each candidate angle; and determining calibration parameters of the array antenna based on the satellite signals collected by the array antenna at the target rotation angle of each rotation period. Through the method, the measurement speed of the calibration parameter of the array antenna can be improved.

Description

Technical Field

[0001] The present application relates to the field of signal processing technology, and in particular to a method and device for measuring array antenna calibration parameters. Background Art

[0002] Array antennas, due to their spatial selectivity and multi-source signal separation capabilities, have become key hardware in Global Navigation Satellite System (GNSS) anti-jamming and spoofing detection systems. However, due to non-ideal factors such as mutual coupling between array elements and inherent phase center offset, antenna patterns exhibit non-uniformity, reducing interference suppression performance and the accuracy of Direction of Arrival (DOA) estimation. Therefore, array antennas require calibration using measured calibration parameters, and rapidly measuring these parameters is crucial. Summary of the Invention

[0003] In view of this, the present application provides a method and apparatus for measuring array antenna calibration parameters to improve the measurement efficiency of array antenna calibration parameters.

[0004] In a first aspect, the present application provides a method for measuring calibration parameters of an array antenna, comprising:

[0005] Grid division of the measurement space of the array antenna;

[0006] Determining, within a current rotation period, a satellite density within each elevation layer of the measurement space after gridding, and determining, based on the satellite density, a weight coefficient for each elevation layer within the current rotation period; wherein the weight coefficient is used to characterize the satellite coverage priority of each elevation layer;

[0007] Determining a coverage score for each candidate angle based on the weight coefficient; wherein the coverage score for the candidate angle is used to represent the satellite coverage benefit after rotating the array antenna according to the candidate angle within the current rotation cycle;

[0008] Determine the target rotation angle of the current rotation cycle based on the coverage score of each candidate angle;

[0009] Based on satellite signals collected by the array antenna at a target rotation angle in each rotation cycle, calibration parameters of the array antenna are determined.

[0010] In a possible implementation, the measurement space is hemispherical; and gridding the measurement space includes:

[0011] stratifying the measurement space according to preset elevation angle intervals;

[0012] For any elevation layer after stratification, the azimuth interval of the elevation layer is determined based on the central elevation angle of the elevation layer, and the elevation layer is grid-divided according to the azimuth interval.

[0013] In one possible implementation, determining a weight coefficient of each elevation layer in a current rotation period based on the satellite density includes:

[0014] For any elevation layer, the inverse of the satellite density in the elevation layer is determined as the initial weight;

[0015] Normalizing the initial weights;

[0016] Determining a dynamic coverage factor corresponding to the elevation layer; wherein the dynamic coverage factor represents the proportion of grid cells in the elevation layer that are not yet covered by satellites within the current rotation cycle;

[0017] Based on the normalized initial weight and the dynamic coverage factor, a weight coefficient of the elevation layer in the current rotation cycle is determined.

[0018] In a possible implementation, determining the coverage score of each candidate angle based on the weight coefficient includes:

[0019] For any candidate angle, determine the number of newly covered grids at the candidate angle; wherein the number of newly covered grids at the candidate angle is the difference in the number of grids covered by the satellite before and after the rotation according to the candidate angle;

[0020] Based on the number of newly added coverage grids and the weight coefficient, a coverage score of the candidate angle is determined.

[0021] In a possible implementation manner, the method further includes:

[0022] For any rotation cycle, determining the coverage status of each grid in the measurement space after rotation according to the target rotation angle of the rotation cycle;

[0023] Determining a cumulative coverage rate of the measurement space based on the coverage status of each grid in the measurement space;

[0024] When the cumulative coverage rate is greater than a preset threshold, the rotation of the array antenna is stopped.

[0025] In one possible implementation, determining the calibration parameters of the array antenna based on satellite signals collected by the array antenna at a target rotation angle in each rotation cycle includes:

[0026] After the array antenna rotates according to a target rotation angle in any rotation cycle, obtaining an amplitude response and a carrier phase measured by each array element of the array antenna in a first direction after the rotation;

[0027] Determining a reference array element in the array antenna, and determining calibration parameters in the first direction based on an amplitude response and a carrier phase measured by the reference array element, and amplitude responses and carrier phases measured by other array elements except the reference array element;

[0028] Based on the calibration parameters of the first direction and the angle between each second direction and the first direction, the calibration parameters in each second direction are determined; wherein, the second direction is the direction of the array antenna during the rotation process according to the target rotation angle, and the calibration parameters in the first direction and the calibration parameters in the second direction constitute the calibration parameters of the array antenna.

[0029] In one possible implementation, determining the calibration parameters in each second direction based on the calibration parameter in the first direction and the angle between each second direction and the first direction includes:

[0030] An interpolation operation is performed based on the calibration parameter of the first direction and the angle between each second direction and the first direction to determine the calibration parameter in each second direction.

[0031] In one possible implementation, determining the calibration parameter in the first direction based on the amplitude response and carrier phase measured by the reference array element, and the amplitude responses and carrier phases measured by array elements other than the reference array element, includes:

[0032] For any other array element, determine a phase offset of the any other array element relative to the reference array element based on a geometric phase shift between the any other array element and the reference array element, a carrier phase measured by the reference array element, and a carrier phase measured by the any other array element;

[0033] and determining an amplitude offset of any one of the other array elements relative to the reference array element based on the amplitude response measured by the reference array element and the amplitude response measured by any one of the other array elements;

[0034] A calibration parameter in the first direction is determined based on the phase offset and the amplitude offset.

[0035] In a second aspect, the present application provides a device for measuring array antenna calibration parameters, the device comprising:

[0036] A division module is used to divide the measurement space of the array antenna into grids;

[0037] A first determination module is configured to determine a satellite density within each elevation layer of the gridded measurement space during a current rotation period, and determine a weight coefficient for each elevation layer during the current rotation period based on the satellite density; wherein the weight coefficient is used to characterize the satellite coverage priority of each elevation layer;

[0038] A scoring module is configured to determine a coverage score for each candidate angle based on the weight coefficient; wherein the coverage score for each candidate angle is used to represent the satellite coverage benefit after rotating the array antenna according to the candidate angle within a current rotation cycle;

[0039] A screening module, configured to determine a target rotation angle for a current rotation cycle based on the coverage score of each candidate angle;

[0040] The second determination module is configured to determine calibration parameters of the array antenna based on satellite signals collected by the array antenna at a target rotation angle in each rotation cycle.

[0041] In a third aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect or any possible implementation manner of the first aspect.

[0042] In a fourth aspect, the present application also provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method described in the first aspect or any possible implementation method of the first aspect are implemented.

[0043] In the measurement method and device for array antenna calibration parameters provided by the present application, after the measurement space of the array antenna is gridded, the weight coefficient of each elevation layer can be determined based on the satellite density in each elevation layer of the measurement space in the current rotation cycle, and then the coverage score of each candidate angle is determined based on the weight coefficient, and the target rotation angle is screened based on the coverage score, and then the array antenna is controlled to rotate according to the screened target rotation angle in the current rotation cycle, and finally the calibration parameters of the array antenna are determined based on the satellite signals collected by the array antenna at the target rotation angle in each rotation cycle. Through this method, the rotation angle can be dynamically selected for each rotation cycle according to the satellite density, so that the measurement of the calibration parameters can be completed with fewer array rotation cycles, thereby improving the speed of calibration parameter measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a comparison diagram of spatial coverage under different measurement methods shown in an embodiment of the present application;

[0045] Figure 2aSchematic diagram of coverage of a measurement method that relies solely on satellite rotation, as shown in an embodiment of the present application;

[0046] Figure 2b Schematic diagram of coverage of a fixed angle rotation method in each rotation cycle shown in an embodiment of the present application;

[0047] Figure 2c This is a schematic diagram of satellite coverage measured by the method provided in this application, shown in an embodiment of this application;

[0048] Figure 3 This is a flow chart of a method for measuring array antenna calibration parameters shown in an embodiment of the present application;

[0049] Figure 4 This is a schematic diagram of the result of dividing the measurement space into equal angles according to an embodiment of the present application;

[0050] Figure 5 This is a schematic diagram of a process of dividing a measurement space into equal areas according to an embodiment of the present application;

[0051] Figure 6 This is a schematic diagram of the result of dividing the measurement space into equal areas according to an embodiment of the present application;

[0052] Figure 7 is a schematic diagram showing a change in a target rotation angle that the array antenna should rotate at each time step, as shown in an embodiment of the present application;

[0053] Figure 8 This is a schematic diagram of a process of collecting satellite signals using an array antenna according to an embodiment of the present application;

[0054] Figure 9 1 is an architectural diagram of a device for measuring array antenna calibration parameters according to an embodiment of the present application;

[0055] Figure 10 It is a structural diagram of a computer device shown in an embodiment of the present application. DETAILED DESCRIPTION

[0056] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0057] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0058] It should be understood that although the terms first, second, third, etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0059] Array antennas rely on measured calibration parameters for calibration. Rapidly measuring these parameters is crucial. Measuring the array antenna pattern is fundamental to calibration. This pattern indicates the direction in which the array antenna should measure satellite signals. This information is then used to determine the array antenna's calibration parameters.

[0060] In the related art, the measurement method that relies only on satellite rotation (Sat-only) or the method of rotating a fixed angle (such as 5°) per rotation cycle (Fixed-5°) is generally used to measure the calibration parameters. Compared with the method provided in this application, the coverage of the measurement space is shown as follows: Figure 1 As shown, the bottom curve represents the coverage of the Sat-only method, the middle curve represents the coverage of the Fixed-5° method, and the top curve represents the coverage of the method provided by this application. It can be seen that whether it is a measurement method that relies solely on satellite rotation or a method that rotates a fixed angle in each rotation cycle, the coverage is relatively low and the coverage rate increases slowly.

[0061] In addition, the measurement method that relies solely on satellite rotation and the method that rotates a fixed angle in each rotation cycle will also have uneven coverage. Figure 2a As shown in the figure, the coverage of Fixed-5° is as follows Figure 2b As shown in the figure, the Sat-only method will lead to serious uneven coverage, while the Fixed-5° method will discretize the satellite trajectory to a certain extent. Although the coverage rate has been improved, there are problems of repeated measurement and local sparseness. The satellite coverage measured based on the method provided by this application is as follows Figure 2c As shown, the method provided by the present application measures not only more areas but also more evenly distributed areas.

[0062] In the measurement method and device for array antenna calibration parameters provided by the present application, after the measurement space of the array antenna is gridded, the weight coefficient of each elevation layer can be determined based on the satellite density in each elevation layer of the measurement space in the current rotation cycle, and then the coverage score of each candidate angle is determined based on the weight coefficient, and the target rotation angle is screened based on the coverage score, and then the array antenna is controlled to rotate according to the screened target rotation angle in the current rotation cycle, and finally the calibration parameters of the array antenna are determined based on the satellite signals collected by the array antenna at the target rotation angle in each rotation cycle. Through this method, the rotation angle can be dynamically selected for each rotation cycle according to the satellite density, so that the measurement of the calibration parameters can be completed with fewer array rotation cycles, thereby improving the speed of calibration parameter measurement, and the method provided by the present application can improve the satellite coverage rate of the measurement space and make the satellite distribution more uniform.

[0063] The following will introduce in detail the measurement method of the array antenna calibration parameters provided by this application in conjunction with specific embodiments. Figure 3 FIG. 1 is a flow chart of a method for measuring array antenna calibration parameters provided in the present application, comprising the following steps:

[0064] S301: Divide the measurement space of the array antenna into grids.

[0065] S302. Determine the satellite density in each elevation layer of the measurement space after grid division within the current rotation cycle, and determine the weight coefficient of each elevation layer within the current rotation cycle based on the satellite density; wherein the weight coefficient is used to characterize the satellite coverage priority of each elevation layer.

[0066] S303. Determine the coverage score of each candidate angle based on the weight coefficient; wherein the coverage score of the candidate angle is used to represent the satellite coverage benefit after the array antenna is rotated according to the candidate angle in the current rotation cycle.

[0067] S304: Determine the target rotation angle of the current rotation cycle based on the coverage score of each candidate angle.

[0068] S305 : Determine calibration parameters of the array antenna based on satellite signals collected by the array antenna at a target rotation angle in each rotation cycle.

[0069] The following is a detailed description of the above steps.

[0070] For S301,

[0071] Optionally, the array antenna can be composed of M array elements, where M is a preset positive integer. The M array elements are installed in a circular structure on a single-axis turntable. The attitude of the array antenna is adjusted by the turntable, thereby changing the orientation of the satellite in the array coordinate system to receive satellite signals from more different directions.

[0072] The measurement space of the array antenna can be hemispherical, and the radius of the sphere is the farthest measurement distance of the measurement antenna.

[0073] In one possible implementation, when dividing the measurement space into grids, an equal-angle division method can be used, that is, the measurement space can be divided into grids according to fixed azimuth intervals. Considering that low elevation angles are easily blocked in actual environments, and there are fewer visible satellites at high elevation angles, the measurement space can be divided into grids according to fixed azimuth intervals within a preset elevation range (such as 10° to 80°). The exemplary grid division results can be as follows: Figure 4 shown.

[0074] However, this division method results in a large number of grids. Therefore, in order to reduce the number of grids and improve measurement efficiency, in another possible implementation, when dividing the measurement space into grids, an equal-area division method can be used.

[0075] Specifically, the measurement space can be layered according to a preset elevation angle interval. For any elevation layer after layering, the azimuth angle interval of the elevation layer can be determined based on the central elevation angle of the elevation layer, and the elevation layer can be gridded according to the azimuth angle interval.

[0076] For example, Figure 5 As shown, θ represents the elevation angle. If the preset elevation angle interval is Δθ = 5°, the elevation layers are divided according to the center elevation angles of 0°, 5°, 10°, etc. Here, the center elevation angle of any elevation layer refers to the angle between the center line of the elevation layer and the equator of the measurement space. For example, for the 0th elevation layer, if Δθ = 5°, the maximum pitch angle of the 0th elevation layer is 2.5°, and the minimum pitch angle is -2.5°.

[0077] Assume that the j-th elevation layer is Δφ j As the azimuth interval for dividing the azimuth, when Δθ and Δφ j When they are relatively small, the area of ​​each grid cell can be approximately expressed as:

[0078] G=R 2 Δφ j Δθcosθ j (1)

[0079] Where R is the radius of the sphere, θ jrepresents the central elevation angle of the jth elevation layer, Δθ represents the elevation layer interval, Δφ j represents the azimuth interval of the j-th elevation layer.

[0080] When θ0 = 0°, the grid divided into the 0th elevation layer with Δφ0 as the azimuth interval can be used as the secondary reference area unit. The area of ​​each grid unit in the 0th elevation layer can be expressed as:

[0081] G=R 2 Δφ0Δθ (2)

[0082] The grid areas in each elevation layer after division in this application can be approximately equal, so it can be expressed as: R 2 Δφ j φΔθ j =R 2 Δφ0Δθ, and then the azimuth interval of the j-th elevation layer can be deduced as:

[0083]

[0084] Here, Δφ0 may be a preset value.

[0085] For example, after the grid is divided according to the above-mentioned equal area division method, the divided grid space is as follows: Figure 6 As shown in this method, different elevation layers contain different numbers of grids. Figure 4 The meshing method shown in Figure 2 reduces the number of meshes after division.

[0086] Using ephemeris data, we can predict the satellite distribution for future time periods. Once the grid is complete, we can use the ephemeris data to determine the projected position of each satellite on the spherical grid. When a satellite exists in the direction corresponding to a grid cell, the spatial direction corresponding to that grid cell is considered covered.

[0087] For S302,

[0088] Optionally, the rotation period of the array antenna is fixed, for example, if it rotates once every 5 minutes, the rotation period is 5 minutes. The rotation period can also be called a time step. The description of the time step below can be understood as a description of the rotation period.

[0089] If the current rotation period is the i-th rotation (i.e., the i-th time step), then in the current rotation period, the number of satellites in the j-th elevation layer can be expressed as:

[0090]

[0091] Among them, s i =(φs ,θ s ) represents the azimuth and elevation angles of the sth satellite, S i represents the set of all visible navigation satellite positions at the i-th time step, and They represent the upper and lower boundaries of the pitch angle range of the j-th elevation layer respectively.

[0092] The satellite density of the j-th elevation layer can be expressed as: Among them, m j Indicates the number of grids in layer j.

[0093] In one possible implementation, when determining the weight coefficient of each elevation layer in the current rotation period based on the satellite density, the following steps may be performed:

[0094] Step a1: For any elevation layer, the inverse of the satellite density in the elevation layer is set as the initial weight.

[0095] For example, the initial weight can be expressed as:

[0096]

[0097] Here, ε is a preset value greater than 0 to prevent the denominator from being zero due to the absence of satellites in a certain elevation layer. Here, the greater the number of grid cells in the jth elevation layer, the greater the corresponding initial weight. Similarly, the fewer satellites in the jth elevation layer, the greater the corresponding initial weight. This indicates whether a layer should be prioritized for coverage, i.e., the satellite coverage priority.

[0098] Step a2: normalize the initial weights.

[0099] Optionally, when normalizing the initial weights, the following formula may be used:

[0100]

[0101] in, Represents the normalized weight, w i,k It represents the initial weight of the k-th elevation layer when taking the maximum or minimum value. The “~” on the right side of the formula represents the candidate, and the formula without “~” on the left side represents the confirmed result.

[0102] Step a3: Determine a dynamic coverage factor corresponding to the elevation layer; wherein the dynamic coverage factor represents the proportion of grid cells in the elevation layer that have not been covered by satellites within the current rotation cycle.

[0103] Alternatively, the dynamic coverage factor can be determined by the following formula:

[0104]

[0105] Among them, C i，j，l ∈{0, 1} represents the coverage status of the lth grid in the jth elevation layer at the i-th time step, 0 means uncovered and 1 means covered.

[0106] Step a4: Determine the weight coefficient of the elevation layer in the current rotation cycle based on the normalized initial weight and the dynamic coverage factor.

[0107] Optionally, when determining the weight coefficient of the j-th elevation layer in the current rotation period (such as the i-th time step), it can be calculated by the following formula:

[0108]

[0109] in, Represents the weight coefficient of the j-th elevation layer at the i-th time step.

[0110] For S303 and S304,

[0111] In one possible implementation, when determining the coverage score of each candidate angle based on the weight coefficient, for any candidate angle, the number of newly added coverage grids under the candidate angle can be determined first; wherein the number of newly added coverage grids under the candidate angle is the difference in the number of grids covered by the satellite before and after the rotation of the candidate angle; and then the coverage score of the candidate angle is determined based on the number of newly added coverage grids and the weight coefficient.

[0112] The candidate angles include multiple rotation angles. For example, if the rotation is in units of 5°, the candidate angles are 0°, 5°, 10°...355°.

[0113] Optionally, for the candidate angle φ k The number of newly added coverage grids at this candidate angle can be calculated using the following formula:

[0114]

[0115] Where Δn i，j (φ k ) represents the candidate angle φ k The number of newly added coverage grids under .

[0116] Optionally, when calculating the candidate angle φ k The coverage score can be calculated using the following formula:

[0117]

[0118] Among them, Score(φk ) represents the candidate angle φ k Coverage score.

[0119] After determining the coverage score of each candidate angle, the candidate angle with the coverage score may be selected as the target rotation angle of the current rotation cycle, ie, the array antenna is rotated according to the target rotation angle in the current rotation cycle.

[0120] For example, after calculating the change in the target rotation angle that the array antenna should rotate at each time step, the following is obtained: Figure 7 As shown, when the target rotation angle is a positive value, it may be a clockwise rotation, and when the target rotation angle is a negative value, it may be a counterclockwise rotation. Therefore, it can be seen that the rotation direction and rotation angle of the array antenna at different time steps may be different.

[0121] In a possible implementation, for any rotation cycle, after determining the target rotation angle of the rotation cycle, the coverage status of each grid may be updated. The updated grid coverage status may determine whether the array antenna continues to rotate.

[0122] Specifically, for any rotation cycle, the coverage status of each grid in the measurement space after rotation according to the target rotation angle of the rotation cycle can be determined. Then, based on the coverage status of each grid in the measurement space, a cumulative coverage rate of the measurement space can be determined. If the cumulative coverage rate exceeds a preset threshold, the rotation of the array antenna is stopped. If the cumulative coverage rate is less than or equal to the preset threshold, the step of determining the target rotation angle can be continued until the cumulative coverage rate exceeds the preset threshold.

[0123] For example, when updating the coverage status of each grid, it can be represented by the following formula:

[0124]

[0125] For S305,

[0126] The satellite signals collected by the array antenna at the target rotation angle in each rotation cycle may refer to the satellite signals collected after the array antenna completes rotation according to the corresponding target rotation angle in each rotation cycle. Figure 8 As shown in the figure, the signals received by each element of the array antenna are processed by the radio frequency channel (RF) and analog-to-digital converter (ADC) in turn and sent to the receiver (Rev) for solution to obtain multiple observation quantities including carrier phase and carrier-to-noise ratio. Then, based on these multiple observation quantities, the calibration parameters of the array antenna are determined.

[0127] In one possible implementation, determining the calibration parameters of the array antenna based on satellite signals collected by the array antenna at a target rotation angle in each rotation cycle may specifically include the following steps:

[0128] Step b1: After the array antenna rotates according to a target rotation angle in any rotation cycle, the amplitude response and carrier phase measured by each array element of the array antenna in a first direction after rotation are obtained.

[0129] Here, the first direction after rotation may refer to the direction of the array antenna after the rotation is completed according to the target rotation angle. The amplitude response and carrier phase measured by each array element may be the observed quantities obtained by the above-mentioned receiver settlement. Here, the amplitude response may be characterized by the carrier-to-noise ratio.

[0130] Step b2: Determine a reference array element in the array antenna, and determine calibration parameters in the first direction based on the amplitude response and carrier phase measured by the reference array element, and the amplitude responses and carrier phases measured by other array elements except the reference array element.

[0131] Specifically, for any other array element, a phase offset of the any other array element relative to the reference array element may be determined based on a geometric phase shift between the any other array element and the reference array element, a carrier phase measured by the reference array element, and a carrier phase measured by the any other array element. Furthermore, an amplitude offset of the any other array element relative to the reference array element may be determined based on an amplitude response measured by the reference array element and an amplitude response measured by the any other array element. Then, a calibration parameter in the first direction may be determined based on the phase offset and the amplitude offset.

[0132] For example, if array element 1 is the reference array element, the carrier phase output by the receiver corresponding to array element i in the first direction is The carrier phase output by the receiver corresponding to reference element 1 in the first direction is The phase shift caused by the array geometry of element i relative to reference element 1 is (is a preset value), then the phase offset of the array element i relative to the reference array element 1 in the first direction can be expressed by the following formula:

[0133]

[0134] Where i = 2, 3, 4…M, represents the sequence number of the array element, and M represents the number of array elements; represents the phase offset of array element i relative to reference array element 1 in the first direction.

[0135] Similarly, the amplitude offset of the satellite signal can be obtained using a similar method. However, the influence of geometric factors can be ignored. Here, the carrier-to-noise ratio is used to characterize the amplitude response. The amplitude offset of array element i relative to reference element 1 in the first direction can be calculated using the following formula:

[0136]

[0137] Where ΔA i represents the amplitude offset of array element i relative to reference array element 1 in the first direction, represents the carrier-to-noise ratio of reference element 1 in the first direction, represents the carrier-to-noise ratio of array element i in the first direction.

[0138] If the first direction is the kth measurement direction, the calibration parameters in the first direction can be:

[0139]

[0140] Among them, A k Indicates the amplitude calibration coefficient of the kth measurement direction, A k It includes the amplitude offset of each array element compared to the reference array element in the kth measurement direction. For example, if the array antenna includes M array elements, then A k For an M-dimensional array, the amplitude offset of the reference element relative to itself can be 1; φ k represents the phase calibration coefficient of the kth measurement direction, φ k Including the phase offset of each array element in the kth measurement direction compared to the reference array element. Similarly, φ k It is also a multi-dimensional queue.

[0141] In addition, a complex calibration coefficient vector C can be constructed, which can be used to correct the steering vector of an M-element array (ie, an array antenna including M elements). The corrected steering vector can be used for DOA estimation.

[0142] Alternatively, the complex calibration coefficient vector can be expressed as:

[0143]

[0144] For the angle from the elevation angle θ, the azimuth angle is The ideal steering vector a of the M-element array is ideal It can be expressed as:

[0145] a ideal =[a1(φ,θ),a2(φ,θ),...,a M (φ,θ)] T (16)

[0146] The ideal guidance vector is corrected using the complex calibration coefficient vector C to obtain the actual guidance vector a cal , which can be expressed as:

[0147]

[0148] Step b3. Based on the calibration parameters of the first direction and the angle between each second direction and the first direction, determine the calibration parameters in each second direction; wherein, the second direction is the direction of the array antenna during the rotation process according to the target rotation angle, and the calibration parameters in the first direction and the calibration parameters in the second direction constitute the calibration parameters of the array antenna.

[0149] Here, the second direction can be understood as the direction covered before the array antenna stops rotating. For example, if the current direction of the array antenna is 10° and the target rotation angle is 30°, the next first direction of the array antenna after completing the rotation is 40°. If the unit rotation angle is 5 degrees, 15°, 20°, 25°, 30°, and 35° can all be used as the second direction.

[0150] After completing the measurement of the calibration parameters in the multiple first directions, the measured sparse data may be expanded into a complete calibration parameter table according to a grid, that is, the calibration parameters in each second direction may be calculated based on an interpolation algorithm.

[0151] Optionally, when determining the calibration parameters in each second direction based on the calibration parameters of the first direction and the angle between each second direction and the first direction, an interpolation operation can be performed based on the calibration parameters of the first direction and the angle between each second direction and the first direction to determine the calibration parameters in each second direction.

[0152] For example, for a signal from the direction (φ, θ), the direction vector in the unit spherical coordinate system can be expressed as:

[0153]

[0154] For any second direction u q , which can be used to compare with the known first direction u k The weighted difference of the spherical angle between them. q and u k The angular distance between them can be defined as:

[0155]

[0156] The second direction u can be obtained by weighted summing the calibration parameters of each first direction q The calibration parameter h q :

[0157]

[0158] Since the satellite navigation signal itself carries precise position information, in a possible implementation, the calibration parameters measured by the method provided in this application can also be verified based on the satellite navigation signal.

[0159] Specifically, after capturing the navigation signal, the captured navigation signal can be calibrated in combination with formulas (16) and (17) to eliminate other phase errors except the array geometry. Then, the DOA of each satellite signal is estimated, and the estimated result is compared with the true direction calculated by the ephemeris to evaluate the effectiveness of the calibration parameters.

[0160] Corresponding to the aforementioned embodiment of the method for measuring array antenna calibration parameters, the present application also provides an embodiment of an apparatus for measuring array antenna calibration parameters.

[0161] See also Figure 9 FIG. 1 is an architecture diagram of a device for measuring array antenna calibration parameters provided in an embodiment of the present application, comprising:

[0162] A division module 901 is used to divide the measurement space of the array antenna into grids;

[0163] A first determination module 902 is configured to determine the satellite density within each elevation layer of the gridded measurement space during a current rotation period, and determine a weight coefficient for each elevation layer during the current rotation period based on the satellite density; wherein the weight coefficient is used to represent the satellite coverage priority of each elevation layer;

[0164] Scoring module 903 is configured to determine a coverage score for each candidate angle based on the weight coefficient; wherein the coverage score for each candidate angle is used to represent the satellite coverage benefit after rotating the array antenna according to the candidate angle within a current rotation cycle;

[0165] A screening module 904 is configured to determine a target rotation angle for the current rotation cycle based on the coverage score of each candidate angle;

[0166] The second determination module 905 is configured to determine calibration parameters of the array antenna based on satellite signals collected by the array antenna at a target rotation angle in each rotation cycle.

[0167] In one possible implementation, the measurement space is hemispherical; and the division module 901, when performing grid division on the measurement space, is configured to:

[0168] stratifying the measurement space according to preset elevation angle intervals;

[0169] For any elevation layer after stratification, the azimuth interval of the elevation layer is determined based on the central elevation angle of the elevation layer, and the elevation layer is grid-divided according to the azimuth interval.

[0170] In one possible implementation, the first determining module 902, when determining the weight coefficient of each elevation layer in the current rotation period based on the satellite density, is configured to:

[0171] For any elevation layer, the inverse of the satellite density in the elevation layer is determined as the initial weight;

[0172] Normalizing the initial weights;

[0173] Determining a dynamic coverage factor corresponding to the elevation layer; wherein the dynamic coverage factor represents the proportion of grid cells in the elevation layer that are not yet covered by satellites within the current rotation cycle;

[0174] Based on the normalized initial weight and the dynamic coverage factor, a weight coefficient of the elevation layer in the current rotation cycle is determined.

[0175] In one possible implementation, the scoring module 903, when determining the coverage score of each candidate angle based on the weight coefficient, is configured to:

[0176] For any candidate angle, determine the number of newly covered grids at the candidate angle; wherein the number of newly covered grids at the candidate angle is the difference in the number of grids covered by the satellite before and after the rotation according to the candidate angle;

[0177] Based on the number of newly added coverage grids and the weight coefficient, a coverage score of the candidate angle is determined.

[0178] In a possible implementation manner, the second determining module 905 is further configured to:

[0179] For any rotation cycle, determining the coverage status of each grid in the measurement space after rotation according to the target rotation angle of the rotation cycle;

[0180] Determining a cumulative coverage rate of the measurement space based on the coverage status of each grid in the measurement space;

[0181] When the cumulative coverage rate is greater than a preset threshold, the rotation of the array antenna is stopped.

[0182] In one possible implementation, the second determination module 905, when determining the calibration parameters of the array antenna based on satellite signals collected by the array antenna at the target rotation angle in each rotation cycle, is configured to:

[0183] After the array antenna rotates according to a target rotation angle in any rotation cycle, obtaining an amplitude response and a carrier phase measured by each array element of the array antenna in a first direction after the rotation;

[0184] Determining a reference array element in the array antenna, and determining calibration parameters in the first direction based on an amplitude response and a carrier phase measured by the reference array element, and amplitude responses and carrier phases measured by other array elements except the reference array element;

[0185] Based on the calibration parameters of the first direction and the angle between each second direction and the first direction, the calibration parameters in each second direction are determined; wherein, the second direction is the direction of the array antenna during the rotation process according to the target rotation angle, and the calibration parameters in the first direction and the calibration parameters in the second direction constitute the calibration parameters of the array antenna.

[0186] In one possible implementation, the second determination module 905, when determining the calibration parameters in each second direction based on the calibration parameters in the first direction and the angle between each second direction and the first direction, is configured to:

[0187] An interpolation operation is performed based on the calibration parameter of the first direction and the angle between each second direction and the first direction to determine the calibration parameter in each second direction.

[0188] In a possible implementation manner, the second determination module 905, when determining the calibration parameter in the first direction based on the amplitude response and carrier phase measured by the reference array element, and the amplitude responses and carrier phases measured by other array elements except the reference array element, is configured to:

[0189] For any other array element, determine a phase offset of the any other array element relative to the reference array element based on a geometric phase shift between the any other array element and the reference array element, a carrier phase measured by the reference array element, and a carrier phase measured by the any other array element;

[0190] and determining an amplitude offset of any one of the other array elements relative to the reference array element based on the amplitude response measured by the reference array element and the amplitude response measured by any one of the other array elements;

[0191] A calibration parameter in the first direction is determined based on the phase offset and the amplitude offset.

[0192] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0193] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the partial description of the method embodiments. The device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0194] The present application also provides a computer-readable storage medium, which stores a computer program. The computer program can be used to execute the method for measuring array antenna calibration parameters described in the above embodiment.

[0195] This application also provides a computer device, see Figure 10 The figure shows a schematic diagram of the structure of the computer device provided in this application. At the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the method for measuring the array antenna calibration parameters described in the above embodiment. Of course, in addition to software implementation, this specification does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0196] Embodiments of the subject matter and functional operations described in this specification may be implemented in the following: digital electronic circuits, tangibly embodied computer software or firmware, computer hardware including the structures disclosed in this specification and their structural equivalents, or a combination of one or more of them. Embodiments of the subject matter described in this specification may be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a tangible, non-transitory program carrier to be executed by a data processing device or to control the operation of the data processing device. Alternatively or additionally, the program instructions may be encoded on an artificially generated propagation signal, such as a machine-generated electrical, optical, or electromagnetic signal, which is generated to encode information and transmit it to a suitable receiver device for execution by the data processing device. The computer storage medium may be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or a combination of one or more of them.

[0197] The processes and logic flows described in this specification can be performed by one or more programmable computers executing one or more computer programs to perform the corresponding functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can be implemented as, special purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

[0198] Computers suitable for executing computer programs include, for example, general-purpose and / or special-purpose microprocessors, or any other type of central processing unit. Typically, the central processing unit will receive instructions and data from a read-only memory and / or random access memory. The basic components of a computer include a central processing unit for implementing or executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will also include one or more mass storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks, or the computer will be operably coupled to such mass storage devices to receive data from them or to transmit data to them, or both. However, a computer does not necessarily have such devices. In addition, a computer can be embedded in another device, such as a mobile phone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a global positioning system (GPS) receiver, or a portable storage device such as a universal serial bus (USB) flash drive, to name a few.

[0199] Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices, including, for example, semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory devices), magnetic disks (e.g., internal hard disks or removable disks), magneto-optical disks, and CD ROM and DVD-ROM disks. The processor and memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0200] Although this specification includes many specific implementation details, these should not be interpreted as limiting the scope of any invention or the scope of protection claimed, but are mainly used to describe the features of specific embodiments of specific inventions. Certain features described in multiple embodiments within this specification may also be implemented in combination in a single embodiment. On the other hand, the various features described in a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. In addition, although features may work in certain combinations as described above and even initially claimed as such, one or more features from the claimed combination may be removed from the combination in some cases, and the claimed combination may point to a sub-combination or a variation of the sub-combination.

[0201] Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring that these operations be performed in the particular order shown or performed sequentially, or that all illustrated operations be performed to achieve the desired results. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of various system modules and components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product, or packaged into multiple software products.

[0202] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the particular order shown or sequential sequence to achieve the desired results. In some implementations, multitasking and parallel processing may be advantageous.

[0203] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for measuring array antenna calibration parameters, characterized in that: The method comprises: Grid division of the measurement space of the array antenna; Determining, within a current rotation period, a satellite density within each elevation layer of the measurement space after gridding, and determining, based on the satellite density, a weight coefficient for each elevation layer within the current rotation period; wherein the weight coefficient is used to characterize the satellite coverage priority of each elevation layer; Determining a coverage score for each candidate angle based on the weight coefficient; wherein the coverage score for the candidate angle is used to represent the satellite coverage benefit after rotating the array antenna according to the candidate angle within the current rotation cycle; Determine the target rotation angle of the current rotation cycle based on the coverage score of each candidate angle; Based on satellite signals collected by the array antenna at a target rotation angle in each rotation cycle, calibration parameters of the array antenna are determined.

2. The method according to claim 1, characterized in that The measurement space is hemispherical; Gridding the measurement space includes: stratifying the measurement space according to preset elevation angle intervals; For any elevation layer after stratification, the azimuth interval of the elevation layer is determined based on the central elevation angle of the elevation layer, and the elevation layer is grid-divided according to the azimuth interval.

3. The method according to claim 1, characterized in that The determining of the weight coefficient of each elevation layer in the current rotation cycle based on the satellite density includes: For any elevation layer, the inverse of the satellite density in the elevation layer is determined as the initial weight; Normalizing the initial weights; Determining a dynamic coverage factor corresponding to the elevation layer; wherein the dynamic coverage factor represents the proportion of grid cells in the elevation layer that are not yet covered by satellites within the current rotation cycle; Based on the normalized initial weight and the dynamic coverage factor, a weight coefficient of the elevation layer in the current rotation cycle is determined.

4. The method according to claim 1, wherein The determining of the coverage score of each candidate angle based on the weight coefficient includes: For any candidate angle, determine the number of newly covered grids at the candidate angle; wherein the number of newly covered grids at the candidate angle is the difference in the number of grids covered by the satellite before and after the rotation according to the candidate angle; Based on the number of newly added coverage grids and the weight coefficient, a coverage score of the candidate angle is determined.

5. The method according to claim 1, wherein The method further comprises: For any rotation cycle, determining the coverage status of each grid in the measurement space after rotation according to the target rotation angle of the rotation cycle; Determining a cumulative coverage rate of the measurement space based on the coverage status of each grid in the measurement space; When the cumulative coverage rate is greater than a preset threshold, the rotation of the array antenna is stopped.

6. The method according to claim 1, wherein The determining of calibration parameters of the array antenna based on satellite signals collected by the array antenna at a target rotation angle in each rotation cycle includes: After the array antenna rotates according to a target rotation angle in any rotation cycle, obtaining an amplitude response and a carrier phase measured by each array element of the array antenna in a first direction after the rotation; Determining a reference array element in the array antenna, and determining calibration parameters in the first direction based on an amplitude response and a carrier phase measured by the reference array element, and amplitude responses and carrier phases measured by other array elements except the reference array element; Based on the calibration parameters of the first direction and the angle between each second direction and the first direction, the calibration parameters in each second direction are determined; wherein, the second direction is the direction of the array antenna during the rotation process according to the target rotation angle, and the calibration parameters in the first direction and the calibration parameters in the second direction constitute the calibration parameters of the array antenna.

7. The method according to claim 6, characterized in that The determining, based on the calibration parameter of the first direction and the angle between each second direction and the first direction, the calibration parameter in each second direction includes: An interpolation operation is performed based on the calibration parameter of the first direction and the angle between each second direction and the first direction to determine the calibration parameter in each second direction.

8. The method according to claim 6, characterized in that The determining the calibration parameter in the first direction based on the amplitude response and carrier phase measured by the reference array element, and the amplitude responses and carrier phases measured by other array elements except the reference array element, includes: For any other array element, determine a phase offset of the any other array element relative to the reference array element based on a geometric phase shift between the any other array element and the reference array element, a carrier phase measured by the reference array element, and a carrier phase measured by the any other array element; and determining an amplitude offset of any one of the other array elements relative to the reference array element based on the amplitude response measured by the reference array element and the amplitude response measured by any one of the other array elements; A calibration parameter in the first direction is determined based on the phase offset and the amplitude offset.

9. A device for measuring array antenna calibration parameters, characterized in that: The device comprises: A division module is used to divide the measurement space of the array antenna into grids; A first determination module is configured to determine a satellite density within each elevation layer of the gridded measurement space during a current rotation period, and determine a weight coefficient for each elevation layer during the current rotation period based on the satellite density; wherein the weight coefficient is used to characterize the satellite coverage priority of each elevation layer; A scoring module is configured to determine a coverage score for each candidate angle based on the weight coefficient; wherein the coverage score for each candidate angle is used to represent the satellite coverage benefit after rotating the array antenna according to the candidate angle within a current rotation cycle; A screening module, configured to determine a target rotation angle for a current rotation cycle based on the coverage score of each candidate angle; The second determination module is configured to determine calibration parameters of the array antenna based on satellite signals collected by the array antenna at a target rotation angle in each rotation cycle.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

11. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method according to any one of claims 1 to 8 are implemented.

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