A method for determining and sorting radar signal polarization ellipse parameters

Abstract

This application belongs to the field of radar signal sorting technology, specifically relating to a method for determining the polarization ellipse parameters of a radar signal, including: calculating the polarization response under multiple polar angles, where i = 1, 2, ..., N are sampling points of the polar angles; if θ0 = 0 and axial ratio θ0 = 0, then determine the polarization ellipse θ0 = 0, where θ0 = 0; otherwise: calculate the potential estimate of the polarization ellipse tilt angle, where the polarization response ρ(θ0) corresponding to the potential estimate of the polarization ellipse tilt angle is calculated. t Furthermore, a radar signal sorting method is provided, comprising: determining the radar signal polarization ellipse parameters based on the aforementioned radar signal polarization ellipse parameter determination method; and using radar signal polarization as a feature dimension for sorting radar signals.

Description

Technical Field

[0001] This application belongs to the field of radar signal sorting technology, specifically relating to a method for determining radar signal polarization ellipse parameters and sorting them. Background Technology

[0002] Radar reconnaissance systems typically sort radar signals using five-dimensional parameters (time of arrival, pulse width, pulse amplitude, direction of arrival, and signal frequency). However, with the increasing complexity of the electromagnetic environment, this method is no longer able to guarantee the reliability of radar signal sorting.

[0003] The form of radar signals received by a radar reconnaissance system is related to the polarization and attitude of the radar antenna. The polarization of most radar antennas is fixed, and the radar antenna attitude is gradually changing relative to the repetition frequency of the radar signal. Therefore, the polarization of the radar signal can be considered a reliable characteristic dimension of the radar signal, which can be used for sorting radar signals.

[0004] Polarization ellipse is one of the methods for characterizing the polarization mode of a radar antenna. The important parameters describing the polarization ellipse are tilt angle and axial ratio. Currently, it is mostly determined by the polarization pattern method. This method fits the polarization ellipse by calculating the polarization response at various polar angles, and then calculates the tilt angle and axial ratio. The structure used is simple and the estimation accuracy is high, but it needs to traverse 0 to 360° and calculate the polarization response at a large number of polar angles, which is inefficient and makes it difficult to guarantee the real-time determination of the tilt angle and axial ratio of the polarization ellipse. It is difficult to implement for radar signal sorting.

[0005] This application is made in view of the aforementioned technical deficiencies.

[0006] It should be noted that the above background information is only used to assist in understanding the inventive concept and technical solution of this invention, and it does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0007] The purpose of this application is to provide a method for determining and sorting radar signal polarization ellipse parameters, in order to overcome or mitigate at least one of the known technical defects.

[0008] The technical solution of this application is:

[0009] One approach provides a method for determining the polarization ellipse parameters of a radar signal, including:

[0010] Calculate multiple polar angles polarization response Where i = 1, 2, ..., N are the sampling points for the polar angle;

[0011] like Then the polarization ellipse is determined to have θ0 = 0 and axial ratio τ = 1, where,

[0012] otherwise:

[0013] Potential estimates for calculating the dip angle of the polarization ellipse in,

[0014] The polarization response ρ(θ) corresponding to the potential estimate of the polarization ellipse tilt angle is calculated. t ), and the corresponding polarization response in its vertical direction. but:

[0015]

[0016]

[0017] According to at least one embodiment of this application, in the above-described method for determining radar signal polarization ellipse parameters, multiple polar angles are calculated. polarization response Specifically:

[0018]

[0019] in,

[0020] s H s V The radar signals received by the horizontally and vertically polarized antennas;

[0021] k = 1, 2, ... K represents the sampling points of the radar signal.

[0022] According to at least one embodiment of this application, in the above-described method for determining the polarization ellipse parameters of a radar signal,

[0023] According to at least one embodiment of this application, in the above-described method for determining the polarization ellipse parameters of a radar signal, N = 7.

[0024] According to at least one embodiment of this application, in the above-described method for determining the polarization ellipse parameters of a radar signal, the polarization response ρ(θ) corresponding to the potential estimate of the polarization ellipse tilt angle is calculated. t ), and the corresponding polarization response in its vertical direction. Specifically:

[0025]

[0026]

[0027] in,

[0028] s H s V The radar signals received by the horizontally and vertically polarized antennas;

[0029] k = 1, 2, ... K represents the sampling points of the radar signal.

[0030] On the other hand, a radar signal sorting method is provided, including:

[0031] The radar signal polarization ellipse parameters are determined based on any of the above-mentioned methods for determining radar signal polarization ellipse parameters.

[0032] Radar signal polarization is used as a feature dimension for sorting radar signals. Attached Figure Description

[0033] Figure 1 This is a schematic diagram comparing the polarization ellipse parameters obtained using the radar signal polarization ellipse parameter determination method of this application with the polarization ellipse parameters under theoretical conditions, provided in an embodiment of this application. Detailed Implementation

[0034] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0035] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0036] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0037] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0038] For space radar signals, the radar reconnaissance system uses two orthogonally polarized antennas for reception. After digital processing, the signals received by the two antennas can be denoted as: s H (k), s V (k), k = 1, 2, ..., K, where s H s V These represent the signals received by the horizontal and vertical polarized antennas, respectively, and k represents the sampling signal sequence index.

[0039] set up Let i = 1, 2, ..., N, be the polarization response of N uniformly sampled points on the polarization ellipse, and its calculation formula is:

[0040]

[0041] in,

[0042]

[0043] i = 1, 2, ..., N represents the polar angle corresponding to the sampling point.

[0044] These represent the maximum and minimum values ​​of the polarization response at N uniform sampling points, respectively.

[0045] if If the radar signal polarization is considered to be circular, then the polarization ellipse tilt angle θ0 = 0 and the axial ratio τ = 1 can be assumed. Otherwise, the polarization ellipse parameters are determined based on the minimum squared distance, as follows:

[0046] Let there be a straight line L: xsinθ - ycosθ = 0 passing through the origin. The sum of the squares of the distances from all points on the polarized ellipse to this line is:

[0047]

[0048] in,

[0049]

[0050]

[0051] According to the minimum sum of squared distance criterion, we can obtain:

[0052]

[0053] in,

[0054] θ t This is a potential estimate of the tilt angle of the polarization ellipse;

[0055] Calculate θ according to formula (1). t The polarization response ρ(θ) in its perpendicular direction t ), By comparing these two values, the polarization ellipse parameters, tilt angle and axial ratio τ, are determined:

[0056]

[0057]

[0058] As those skilled in the art will understand, the above provides a method for determining the polarization ellipse parameters of a radar signal based on the minimum sum of squares of distance. Based on the minimum sum of squares of distance and its criteria, the tilt angle and axial ratio of the polarization ellipse are estimated through the polarization response of a few polar angles.

[0059] In a specific example, under a radar signal simulation environment, the signal received by the radar reconnaissance system is as follows: Among them, f c =100MHz, pulse width is 1μs, sampling frequency f s =2.4GHz, signal-to-noise ratio SNR=5dB, number of sampling points for polarization response N=7.

[0060] For the example above, under ideal conditions, the polarization ellipse of the received radar signal has an inclination angle of 30° and an axial ratio of 5.

[0061] For the above example, using the aforementioned method for determining the radar signal polarization ellipse parameters, 1000 Monte Carlo experiments were conducted. The mean tilt angle of the radar signal polarization ellipse was 30.0253°, with a mean square error of 1.07°, and the mean axial ratio was 1.69 with a variance of 0.03. Comparison with the radar signal polarization ellipse tilt angle and axial ratio under ideal conditions is shown below. Figure 1 As shown.

[0062] The comparison shows that the radar signal polarization ellipse parameter determination method described above yields a radar signal polarization ellipse tilt angle that is close to the tilt angle under ideal conditions, exhibiting high accuracy. However, the obtained axial ratio differs significantly from the axial ratio under theoretical conditions. This phenomenon is due to the influence of noise. Nevertheless, under the same signal-to-noise ratio, the axial ratio of the polarization ellipse exhibits high stability and can still be used as a characteristic dimension of the polarization ellipse for radar signal sorting, demonstrating high reliability.

[0063] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A method for determining the polarization ellipse parameters of a radar signal, characterized in that, include: Calculate multiple polar angles polarization response Where i = 1, 2, ..., N are the sampling points for the polar angle; like Then, the polarization ellipse is determined to have an inclination angle θ0 = 0 and an axial ratio τ = 1, where, otherwise: Potential estimates for calculating the dip angle of the polarization ellipse in, The polarization response ρ(θ) corresponding to the potential estimate of the polarization ellipse tilt angle is calculated. t ), and the corresponding polarization response in its vertical direction. but:

2. The method for determining radar signal polarization ellipse parameters according to claim 1, characterized in that, Calculate multiple polar angles polarization response Specifically: in, s H , s V Radar signals received by horizontal, vertical polarized antennas; k = 1, 2, ... K represents the sampling points of the radar signal.

3. The method for determining radar signal polarization ellipse parameters according to claim 1, characterized in that, 4. The method for determining radar signal polarization ellipse parameters according to claim 1, characterized in that, N＝7。 5. The method for determining radar signal polarization ellipse parameters according to claim 1, characterized in that, The polarization response ρ(θ) corresponding to the potential estimate of the polarization ellipse tilt angle is calculated. t ), and the corresponding polarization response in its vertical direction. Specifically: in, s H , s V Radar signals received by horizontal, vertical polarized antennas; k = 1, 2, ... K represents the sampling points of the radar signal.

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