A method for measuring angles using a two-dimensional multi-baseline phase interferometer with a special-shaped array

Abstract

The present application belongs to the field of airborne fire control radar, and particularly relates to a method for angle measurement of a two-dimensional multi-baseline phase interferometer with a special-shaped array. The method comprises: obtaining array elements involved in angle measurement, and calibrating the channels of each array element; determining three-dimensional coordinate axes based on the radar array surface, wherein the horizontal axis is the X axis, the vertical axis is the Y axis, and the vertical radar array surface is the Z axis, and according to the spacing between each array element on the Y axis, a multi-baseline phase interferometer is used to successively infer the angle deambiguation algorithm to solve the first spatial incoming wave angle; converting the array element phase difference not on the X axis to the mapping array element on the X axis, and according to the spacing between each array element on the X axis and the mapping array element, a multi-baseline phase interferometer is used to successively infer the angle deambiguation algorithm to solve the second spatial incoming wave angle; calculating the azimuth and elevation angle of the radar system of the incoming wave; performing N samplings, and looping through steps 2 to 4, and calculating the average value of N groups of azimuth and elevation angles as the final incoming wave direction.

Description

Technical Field

[0001] The present application belongs to the field of airborne fire control radar, and in particular relates to an angle measurement method of a two-dimensional multi-baseline phase interferometer with a special-shaped array. Background Art

[0002] Modern warfare has many characteristics, such as high degree of informatization, non-contact beyond visual range, and integrated warfare equipment. Wars are now highly informatized, and informatization means that the level of confrontation between the enemy and us is more concentrated on the information level rather than the weapon lethality level. The radar electronic warfare system takes radar and its component systems as its combat targets, and relies on radar reconnaissance aircraft and radar jammers as its important combat equipment, and carries out electromagnetic wave emission, absorption, transmission and other forms. The radar electronic warfare system has developed from the initial discrete single function to today's multifunctional integrated system, and has continuously realized the requirements of system standardization, generalization, and serialization, and has achieved rapid development in theory and application. The multifunctional integrated radar electronic warfare system is to organically integrate related equipment and technologies of different categories, frequency bands and functions into an integrated comprehensive system, with the advantages of resource redundancy, information resource sharing, dynamic reorganization, high utilization rate, etc., which can greatly improve the overall effectiveness of joint operations.

[0003] The comprehensive integration of radar and electronic warfare systems has become an inevitable requirement for the development of electronic information technology and the information needs of modern warfare. The integration of radar and electronic warfare equipment greatly saves energy consumption, reduces space occupation, improves the combat effectiveness and mobility of the platform, increases the utilization rate of hardware equipment, and improves the effect of interference, which has become an inevitable trend in the development of radar electronic warfare systems today. How to achieve the integrated processing of radar signals and electronic warfare signals is the key to whether the system can work effectively. Especially in a complex electromagnetic environment, in order to ensure the stealth performance of the carrier aircraft, in order to have the ability to detect the enemy first, accurately locate, and quickly strike, it is necessary to frequently switch between radar and electronic warfare work and assist each other, so there is a need to share an antenna. The conventional angle measurement method of electronic warfare is multi-baseline phase interferometer angle measurement, which generally requires that the array elements are distributed in a straight line, and the arrangement interval of the array elements has certain constraints. In the multi-baseline phase interferometer angle measurement system, in order to improve the angle measurement accuracy, it is hoped to increase the length of the baseline; and in order to avoid phase cycle ambiguity, the length of the baseline is required not to exceed half of the wavelength of the electromagnetic wave. In order to solve this contradiction, currently, multi-baseline interferometers are mostly used for angle measurement, using short baselines to resolve phase cycle ambiguity and long baselines to obtain high angle measurement accuracy. However, under the premise of ensuring the normal use of active phased array radar (including full array, sub-array and other working modes), in order to achieve two-dimensional interferometric angle measurement, it is difficult to simultaneously achieve an array method that sets two axes on the array surface in a straight line and meets the above constraints.

[0004] Therefore, it is desired to have a technical solution to overcome or at least alleviate at least one of the above-mentioned defects of the prior art. Summary of the invention

[0005] The purpose of the present application is to provide an angle measurement method of a two-dimensional multi-baseline phase interferometer with a special-shaped array to solve at least one problem existing in the prior art.

[0006] The technical solution of this application is:

[0007] A method for measuring angles using a two-dimensional multi-baseline phase interferometer with a special-shaped array, comprising:

[0008] Step 1: Obtain array elements involved in angle measurement and perform channel calibration on each array element;

[0009] Step 2: Determine the three-dimensional coordinate axis based on the radar array, where the horizontal axis is the X-axis, the vertical axis is the Y-axis, and the vertical radar array is the Z-axis. According to the spacing between the array elements on the Y-axis, use the multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm to solve the first spatial incoming wave angle;

[0010] Step 3: Convert the phase difference of the array element not on the X-axis to the mapping array element on the X-axis, and solve the second space incoming wave angle by using the multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm according to the spacing between the array elements on the X-axis and the mapping array elements;

[0011] Step 4: Calculate the azimuth and elevation angle of the radar system of the incoming wave according to the first spatial incoming wave angle and the second spatial incoming wave angle;

[0012] Step 5: Perform N samplings, and repeat steps 2 to 4 in a loop to calculate the average value of N groups of azimuth angles and elevation angles as the final incoming wave direction.

[0013] In at least one embodiment of the present application, in step 1, 6 array elements participating in angle measurement are obtained, and channel calibration is performed on each array element.

[0014] In at least one embodiment of the present application, in step 2, after the three-dimensional coordinate axes are determined, the coordinates of each array element are respectively:

[0015] A1=(0,0,0)

[0016] A2=(7λ / 2,0,0)

[0017] A3=(14λ / 2,3λ / 2,0)

[0018] A4=(29λ / 2,5λ / 2,0)

[0019] A5=(0,7λ / 2,0)

[0020] A6=(0,15λ / 2,0)

[0021] Where λ is the measurement wavelength.

[0022] In at least one embodiment of the present application, in step 2, according to the spacing between each array element on the Y axis, using a multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm to solve the first spatial incoming wave angle includes:

[0023] The wave coming from any point in the far field is When the target is 1000m away from the radar array, the incoming wave signals received by the radar array are considered to be parallel;

[0024] According to the spacing between the array elements on the Y axis, we can get:

[0025]

[0026] Among them, Φ ij is the unambiguous phase difference between array elements, φ i is the true phase of the array element carrier, △φ i is the array element carrier phase error, Φ i ' j K is the phase difference between the carrier phases of the array elements in the main value interval, i is an integer fuzzy number;

[0027] After defuzzification, we get:

[0028]

[0029] Among them, Θ1∈(-π,π] corresponds to θ∈(-π / 2,π / 2] one by one, and there is no ambiguity;

[0030] Calculate the 1x accuracy unambiguous incident angle estimate using formula Θ1

[0031]

[0032] use Calculate K1 value and 7 times more accurate unambiguous incident angle estimate

[0033]

[0034] Among them, INT is the rounding operation;

[0035] use Calculate K3 and 15 times more accurate unambiguous angle of incidence estimates

[0036]

[0037] That is, the first spatial incoming wave angle solved by the multi-baseline phase interferometer's recursive angle deambiguation algorithm.

[0038] In at least one embodiment of the present application, in step 3, the array element A3 is mapped to the array element A on the X-axis. 3′ The coordinates are:

[0039] A 3′ =(14λ / 2,0,0)

[0040] Array element A4 is mapped to array element A on the X axis 4′ The coordinates are:

[0041] A 4′ =(29λ / 2,0,0).

[0042] In at least one embodiment of the present application, in step 3, according to the spacing between each array element and the mapping array element on the X-axis, solving the second spatial incoming wave angle by using a multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm includes:

[0043] According to the spacing between each array element and the mapping array element on the X-axis, we can get:

[0044]

[0045] Among them, Φ ij is the unambiguous phase difference between array elements, Φ ij′ is the unambiguous phase difference between the array element and the mapping element, Φ i′j′ is the unambiguous phase difference between the mapping elements, φ i is the true phase of the array element carrier, △φ i is the array element carrier phase error, Φ i ' j K is the phase difference between the carrier phases of the array elements in the main value interval, i is an integer fuzzy number;

[0046] After defuzzification, we get:

[0047]

[0048] Among them, Θ2∈(-π,π] corresponds to θ∈(-π / 2,π / 2] one by one, and there is no ambiguity;

[0049] Calculate the 1x accuracy unambiguous incident angle estimate using formula Θ2

[0050]

[0051] use Calculate K4 value and 7 times more accurate unambiguous incident angle estimate

[0052]

[0053] Among them, INT is the rounding operation;

[0054] use Calculate K6 and 15 times more accurate unambiguous angle of incidence estimates

[0055]

[0056] use Calculate K7 and 29 times more accurate unambiguous angle of incidence estimates

[0057]

[0058] That is, the second spatial incoming wave angle obtained by the multi-baseline phase interferometer's successive inference angle deambiguation algorithm.

[0059] In at least one embodiment of the present application, in step 4, calculating the azimuth angle and the elevation angle of the radar system of the incoming wave according to the first spatial incoming wave angle and the second spatial incoming wave angle includes:

[0060] The azimuth of the incoming wave from the radar system is:

[0061]

[0062] The elevation angle of the incoming radar wave is:

[0063]

[0064] In at least one embodiment of the present application, in step five, N≥500.

[0065] The invention has at least the following beneficial technical effects:

[0066] The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer of the present application fully considers the errors in the detection process, improves the angle accuracy of a single calculation by successively inferring the angle deambiguation algorithm through the multi-baseline phase interferometer, and reduces random noise through multiple measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 This is a schematic diagram of a special-shaped array of an active phased array radar according to an embodiment of the present application;

[0068] Figure 2It is a schematic diagram of spatial coordinates and horizontal mapping of a special-shaped array according to an embodiment of the present application;

[0069] Figure 3 It is a schematic diagram of the azimuth and elevation conversion coordinates of the radar array according to one embodiment of the present application. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the embodiment of this application will be described in more detail below in conjunction with the drawings in the embodiment 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 embodiments are part of the embodiments of this application, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be construed as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0071] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present application.

[0072] The following is combined with Figures 1 to 3 This application is described in further detail.

[0073] The present application provides a method for measuring angles using a two-dimensional multi-baseline phase interferometer with a special-shaped array, comprising the following steps:

[0074] Step 1: Obtain array elements involved in angle measurement and perform channel calibration on each array element;

[0075] Step 2: Determine the three-dimensional coordinate axis based on the radar array, where the horizontal axis is the X-axis, the vertical axis is the Y-axis, and the vertical radar array is the Z-axis. According to the spacing between the array elements on the Y-axis, use the multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm to solve the first spatial incoming wave angle;

[0076] Step 3: Convert the phase difference of the array element not on the X-axis to the mapping array element on the X-axis, and solve the second space incoming wave angle by using the multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm according to the spacing between the array elements on the X-axis and the mapping array elements;

[0077] Step 4: Calculate the azimuth and elevation angle of the radar system of the incoming wave according to the first spatial incoming wave angle and the second spatial incoming wave angle;

[0078] Step 5: Perform N samplings, and repeat steps 2 to 4 in a loop to calculate the average value of N groups of azimuth angles and elevation angles as the final incoming wave direction.

[0079] like Figure 1 As shown in the figure, under the premise of ensuring the normal operation of the active phased array radar, the array elements reserved for two-dimensional spatial interferometric angle measurement are generally at the edge of the array surface. Under the condition of ensuring multiple array elements in one axis, it is generally difficult to arrange the array elements in another axis in a straight line. Therefore, exploring the method of two-dimensional interferometric angle measurement with special-shaped arrays has great engineering practical significance.

[0080] The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer of the present application takes six array elements for two-dimensional interference angle measurement on the array plane as an example. First, the six array elements need to be calibrated for channel.

[0081] Secondly, the three-dimensional coordinate axes are determined based on the radar array, where the horizontal is the X-axis, the vertical is the Y-axis, and the vertical radar array is the Z-axis. After determining the three-dimensional coordinate axes, the coordinates of the six array elements are:

[0082] A1=(0,0,0)

[0083] A2=(7λ / 2,0,0)

[0084] A3=(14λ / 2,3λ / 2,0)

[0085] A4=(29λ / 2,5λ / 2,0)

[0086] A5=(0,7λ / 2,0)

[0087] A6=(0,15λ / 2,0)

[0088] Where λ is the measurement wavelength.

[0089] In step 2, according to the spacing between the array elements on the Y axis, the angle of the first spatial wave is solved by using a multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm, including:

[0090] The wave coming from any point in the far field is When the target is far away from the antenna array (1000m away), the incoming signals received by the radar array can be considered parallel.

[0091] According to the spacing between the array elements on the Y axis, we can get:

[0092]

[0093] Among them, Φ ij is the unambiguous phase difference between array elements, φ i is the true phase of the array element carrier, △φ i is the array element carrier phase error, Φ i ' j K is the phase difference between the carrier phases of the array elements in the main value interval, i is an integer fuzzy number;

[0094] It can be seen from equations (1)-(3) that there will be phase ambiguity when measuring the incident angle between any two baselines. To obtain a high-precision incident angle, deambiguation processing is required;

[0095] After defuzzification, we get:

[0096]

[0097] Among them, Θ1∈(-π,π] corresponds to θ∈(-π / 2,π / 2] one by one, and there is no ambiguity;

[0098] The angle deambiguation algorithm is based on the multi-baseline phase interferometer:

[0099] Calculate the 1x accuracy unambiguous incident angle estimate using formula Θ1

[0100]

[0101] use Calculate K1 value and 7 times more accurate unambiguous incident angle estimate

[0102]

[0103] Among them, INT is the rounding operation;

[0104] use Calculate K3 and 15 times more accurate unambiguous angle of incidence estimates

[0105]

[0106] That is, the first spatial incoming wave angle solved by the multi-baseline phase interferometer's recursive angle deambiguation algorithm.

[0107] The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer of the present application is as follows: Figure 2 As shown, array elements A3 and A4 are not on the X-axis, and the mapping array element of array element A3 on the X-axis is A 3′ , the mapping element of element A4 on the X-axis is A 4′, mapping element A 3′ The coordinates are:

[0108] A 3′ =(14λ / 2,0,0)

[0109] Mapping Element A 4′ The coordinates are:

[0110] A 4′ =(29λ / 2,0,0).

[0111] In step 3, according to the spacing between each array element and the mapping array element on the X-axis, the angle of the second space incoming wave is solved by using the multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm, including:

[0112] According to the spacing between each array element and the mapping array element on the X-axis, we can get:

[0113]

[0114] Among them, Φ ij is the unambiguous phase difference between array elements, Φ ij′ is the unambiguous phase difference between the array element and the mapping element, Φ i′j′ is the unambiguous phase difference between the mapping elements, φ i is the true phase of the array element carrier, △φ i is the array element carrier phase error, Φ i ' j K is the phase difference between the carrier phases of the array elements in the main value interval, i is an integer fuzzy number;

[0115] Wherein formula (12) is derived from formula (11), similar to formulas (13) and (14);

[0116] After defuzzification, we get:

[0117]

[0118] Among them, Θ2∈(-π,π] corresponds to θ∈(-π / 2,π / 2] one by one, and there is no ambiguity;

[0119] The angle deambiguation algorithm is based on the multi-baseline phase interferometer:

[0120] Calculate the 1x accuracy unambiguous incident angle estimate using formula Θ2

[0121]

[0122] use Calculate K4 value and 7 times more accurate unambiguous incident angle estimate

[0123]

[0124] Among them, INT is the rounding operation;

[0125] use Calculate K6 and 15 times more accurate unambiguous angle of incidence estimates

[0126]

[0127] use Calculate K7 and 29 times more accurate unambiguous angle of incidence estimates

[0128]

[0129] That is, the second spatial incoming wave angle obtained by the multi-baseline phase interferometer's successive inference angle deambiguation algorithm.

[0130] like Figure 3 As shown, in the spatial angle of the incoming wave direction calculated by the above process and Under the premise of , calculate the azimuth angle β and elevation angle α that meet the radar use:

[0131] Among them, the azimuth of the incoming wave is:

[0132]

[0133] The elevation angle of the incoming radar wave is:

[0134]

[0135] In the preferred embodiment of the present application, in order to reduce random noise, each array element uses N measurements (N ≥ 500), and then calculates the azimuth angle β of each measurement. i and pitch angle α i (1≤i≤500), and then find the average value and As the final incoming wave direction angle.

[0136] It is specially noted here that when the positions of the array elements used for two-dimensional interferometric angle measurement are inconsistent with the settings of the embodiment of the present application, the method and concept are still applicable.

[0137] The angle measurement method of the two-dimensional multi-baseline phase interferometer with a special-shaped array in the present application can realize the angle measurement of the two-dimensional multi-baseline phase interferometer with a special-shaped array, and can assist radar detection and electronic warfare interference through the measured two-dimensional angle. The present application fully considers the errors in the detection process, and improves the angle accuracy of a single calculation by using a multi-baseline phase interferometer to successively infer the angle deambiguation algorithm, and reduces random noise through multiple measurements.

[0138] 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 method for measuring angles using a two-dimensional multi-baseline phase interferometer with a special-shaped array, characterized in that: include: Step 1: Obtain array elements involved in angle measurement and perform channel calibration on each array element; Step 2: Determine the three-dimensional coordinate axis based on the radar array, where the horizontal axis is the X-axis, the vertical axis is the Y-axis, and the vertical radar array is the Z-axis. According to the spacing between the array elements on the Y-axis, use the multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm to solve the first spatial incoming wave angle; Step 3: Convert the phase difference of the array element not on the X-axis to the mapping array element on the X-axis, and solve the second space incoming wave angle by using the multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm according to the spacing between the array elements on the X-axis and the mapping array elements; Step 4: Calculate the azimuth and elevation angle of the radar system of the incoming wave according to the first spatial incoming wave angle and the second spatial incoming wave angle; Step 5: Perform N samplings, and repeat steps 2 to 4 in a loop to calculate the average value of N groups of azimuth angles and elevation angles as the final incoming wave direction.

2. The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer according to claim 1 is characterized in that: In step 1, 6 array elements involved in angle measurement are obtained, and channel calibration is performed on each array element.

3. The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer according to claim 2 is characterized in that: In step 2, after determining the three-dimensional coordinate axes, the coordinates of each array element are: A1＝(0,0,0) A2=(7λ / 2,0,0) A3=(14λ / 2,3λ / 2,0) A4=(29λ / 2,5λ / 2,0) A5=(0,7λ / 2,0) A6=(0,15λ / 2,0) Where λ is the measurement wavelength.

4. The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer according to claim 3 is characterized in that: In step 2, according to the spacing between the array elements on the Y axis, the angle of the first spatial wave is solved by using a multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm, including: The wave from any point in the far field is When the target is 1000m away from the radar array, the incoming wave signals received by the radar array are considered to be parallel; According to the spacing between the array elements on the Y axis, we can get: Among them, Φ ij is the unambiguous phase difference between array elements, φ i is the true phase of the array element carrier, △φ i is the array element carrier phase error, Φ i ' j K is the phase difference between the carrier phases of the array elements in the main value interval, i is an integer fuzzy number; After defuzzification, we get: Among them, Θ1∈(-π,π] corresponds to θ∈(-π / 2,π / 2] one by one, and there is no ambiguity; Calculate the 1x accuracy unambiguous incident angle estimate using formula Θ1 use Calculate K1 value and 7 times more accurate unambiguous incident angle estimate Among them, INT is the rounding operation; use Calculate K3 and 15 times more accurate unambiguous angle of incidence estimates That is, the first spatial incoming wave angle solved by the multi-baseline phase interferometer's recursive angle deambiguation algorithm.

5. The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer according to claim 4 is characterized in that: In step 3, the mapping of element A3 on the X-axis is 3′ The coordinates are: A 3′ =(14λ / 2.0.0) Array element A4 is mapped to array element A on the X axis 4′ The coordinates are: A 4′ =(29λ / 2,0,0).

6. The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer according to claim 5 is characterized in that: In step 3, according to the spacing between each array element and the mapping array element on the X-axis, the angle of the second space incoming wave is solved by using the multi-baseline phase interferometer to iteratively estimate the angle deambiguation algorithm, including: According to the spacing between each array element and the mapping array element on the X-axis, we can get: Among them, Φ ij is the unambiguous phase difference between array elements, Φ ij′ is the unambiguous phase difference between the array element and the mapping element, Φ i′j′ is the unambiguous phase difference between the mapping elements, φ i is the true phase of the array element carrier, △φ i is the array element carrier phase error, Φ i ' j K is the phase difference between the carrier phases of the array elements in the main value interval, i is an integer fuzzy number; After defuzzification, we get: Among them, Θ2∈(-π,π] corresponds to θ∈(-π / 2,π / 2] one by one, and there is no ambiguity; Calculate the 1x accuracy unambiguous incident angle estimate using formula Θ2 use Calculate K4 value and 7 times more accurate unambiguous incident angle estimate Among them, INT is the rounding operation; use Calculate K6 and 15 times more accurate unambiguous angle of incidence estimates use Calculate K7 and 29 times more accurate unambiguous angle of incidence estimates That is, the second spatial incoming wave angle obtained by the multi-baseline phase interferometer's successive inference angle deambiguation algorithm.

7. The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer according to claim 6 is characterized in that: In step 4, calculating the azimuth and elevation angle of the radar system of the incoming wave according to the first spatial incoming wave angle and the second spatial incoming wave angle includes: The azimuth of the incoming wave from the radar system is: The elevation angle of the incoming radar wave is:

8. The angle measurement method of the special-shaped array two-dimensional multi-baseline phase interferometer according to claim 7 is characterized in that: In step 5, N ≥ 500.

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