Method for accurately measuring radar signal parameters in complex electromagnetic environment

Abstract

The invention discloses a method for accurately measuring radar signal parameters in a complex electromagnetic environment, which belongs to the technical field of radars, and comprises the following steps of: receiving and digitally sampling radar signals through a signal receiver, calculating waveform entropy to extract stable detection signals, performing primary channel division on the signals, and performing secondary channel division on the signals; the method comprises the following steps: detecting basic characteristics of each channel and generating a primary frequency measurement value, further refining channel division under the guidance of the primary measurement value, gradually improving the frequency measurement precision, generating intermediate and final accurate frequency measurement values, ensuring that a measurement result meets a tolerance requirement through error verification, and reporting the result to an upper computer. The technical problem of accurate measurement of radar signal parameters in a complex electromagnetic environment is solved, the accuracy of frequency measurement is remarkably improved, quick response to frequency spectrum change is realized, good dynamic adaptability is achieved, the recognition capability of target signals is effectively improved, and the reliability of a final measurement result is ensured.

Description

Technical Field

[0001] The invention belongs to the field of radar technology, and in particular relates to a method for accurately measuring radar signal parameters in a complex electromagnetic environment. Background Art

[0002] There are a large number of high-density and diverse electromagnetic signals in complex electromagnetic environments. These signals have the characteristics of wide spectrum coverage, complex modulation methods, and serious overlap and interference between signals. Although traditional electronic detection technology can achieve a certain degree of signal capture and parameter estimation, it has the following shortcomings in terms of frequency accuracy, data processing efficiency and anti-interference ability:

[0003] Low frequency measurement accuracy: Existing digital channelized receivers rely on broadband or ultra-wideband technology. Although they have high spectrum coverage capabilities, they may face problems such as signal overlap and cross-interference when processing multi-frequency signals, resulting in deviations in frequency measurement values.

[0004] Low data processing efficiency: Broadband reconnaissance technology needs to process massive amounts of data, and in complex signal environments, computational delays or missed judgments often occur, making it impossible to meet real-time requirements.

[0005] Limited anti-interference capability: In high-interference environments, existing detection equipment is easily obscured by strong interference signals, making it difficult to extract weak target signals. Existing technologies rely on large amounts of training data and algorithm optimization; they have high requirements for hardware and software performance; and they may face issues such as algorithm security and data privacy.

[0006] Poor dynamic adaptability: Faced with the dynamic changes in the spectrum of complex electromagnetic environments, traditional equipment lacks targeted processing strategies, which can easily lead to decreased detection sensitivity or increased misjudgment rate. Summary of the invention

[0007] The purpose of the present invention is to provide a method for accurately measuring radar signal parameters in a complex electromagnetic environment, thereby solving the technical problem of accurately measuring radar signal parameters in a complex electromagnetic environment.

[0008] To achieve the above object, the present invention adopts the following technical solution:

[0009] A method for accurately measuring radar signal parameters in a complex electromagnetic environment comprises the following steps:

[0010] Step 1: Use a signal receiver to receive radar signals in a complex electromagnetic environment, digitally sample the received radar signals, calculate the waveform entropy, extract a stable detection waveform sequence, and generate preprocessed detection signal data D 1 ;

[0011] Step 2: The signal receiver processes the pre-processed detection signal data D 1Perform primary channel division and detect signal data D 1 Divided into multiple channels, the channel detection module performs preliminary detection of frequency, amplitude, phase, pulse width and arrival time of each channel signal;

[0012] If the signal amplitude of at least one channel exceeds the preset threshold value, the signal processing module starts to calculate the phase difference and frequency characteristics of each channel signal and generates a primary frequency measurement value f 1 ;

[0013] Step 3: Measure the value f at the primary frequency 1 Under the guidance of , the channel division range is further refined to generate intermediate frequency measurement values;

[0014] Step 4: Under the guidance of the intermediate frequency measurement value, the final accurate frequency measurement value is generated by further refining the channel division and interpolation fitting;

[0015] Step 5: Perform error verification on the final frequency measurement value and the previous level measurement value. If the error tolerance requirement is met, the measurement result is reported to the host computer, otherwise it is returned for further processing.

[0016] Preferably, when executing step 1, the following steps are specifically included:

[0017] Step 1-1: Use a signal receiver to receive radar signals in a complex electromagnetic environment and digitally sample the signals;

[0018] Step 1-2: The signal receiver calculates the waveform entropy of the received signal and extracts a stable detection waveform sequence;

[0019] Step 1-3: Generate pre-processed detection signal data D 1 , for use in subsequent steps.

[0020] Preferably, when executing step 2, the following steps are specifically included:

[0021] Step 2-1: The signal receiver detects the signal data D 1 Divided into multiple channels, each with a bandwidth of 9.375MHz;

[0022] Step 2-2: The channel detection module performs preliminary detection of the frequency, amplitude, phase, pulse width and arrival time of each channel signal;

[0023] Step 2-3: If the signal amplitude of at least one channel exceeds the preset threshold value, the signal processing module starts to calculate the phase difference and frequency characteristics of each channel signal to generate a primary frequency measurement value f 1 .

[0024] Preferably, when executing step 3, the following steps are specifically included:

[0025] Step 3-1: Measure the value f at the primary frequency 1 Under the guidance of , the signal receiver re-divides the channels and refines the frequency range;

[0026] Step 3-2: The channel detection module detects the amplitude and frequency characteristics of the signal in the channel and generates an intermediate frequency measurement value f 2 ;

[0027] Step 3-3: If the intermediate frequency measurement value f 2 The primary frequency measurement value f 1 If the absolute error is greater than the preset tolerance, the loop continues to step 3.1; otherwise, it goes to step 4.

[0028] Preferably, when executing step 4, the specific steps are as follows:

[0029] Step 4-1: Measure the value f at an intermediate frequency 2 Under the guidance of the signal receiver, the channel division is further refined, and the bandwidth of each channel is reduced to 25kHz;

[0030] Step 4-2: The signal processing module combines the amplitude characteristics of each channel and generates the final accurate frequency measurement value f through interpolation fitting. 3 .

[0031] Preferably, when executing step 5, the specific steps are as follows:

[0032] Step 5-1: Determine the final accurate frequency measurement value f 3 Whether the absolute error with the previous frequency measurement value is less than the allowable error tolerance;

[0033] Step 5-2: If the error meets the requirements, the frequency measurement result f 3 Report through the host computer, otherwise return to step 4 and continue iteration.

[0034] Preferably, when executing step 2-1, the detection signal data D 1 Divided into 256 channels.

[0035] The invention discloses a method for accurately measuring radar signal parameters in a complex electromagnetic environment, which solves the technical problem of accurately measuring radar signal parameters in a complex electromagnetic environment. The invention significantly improves the accuracy of frequency measurement by multi-level channel refinement division, gradually optimizes the frequency range, and combines interpolation fitting technology. The invention guides subsequent channel division according to the primary frequency measurement value, realizes rapid response to spectrum changes, has good dynamic adaptability, uses waveform entropy calculation to extract stable detection signals, and sets amplitude thresholds and error tolerances in each level of processing, which effectively improves the recognition ability of target signals. The invention ensures the reliability of the final measurement result through error verification and loop iteration mechanism, and avoids frequency measurement errors caused by signal processing deviations. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is the main flow chart of the present invention;

[0037] Figure 2 This is a structural diagram of an 8-way parallel multi-phase filter of the present invention;

[0038] Figure 3 A schematic diagram of the frequency response of a channel forming filter of a channelized receiver of the present invention;

[0039] Figure 4 This is a schematic diagram of calculating the signal entropy of a received pulse of the present invention:

[0040] Figure 5 It is a schematic diagram of the measurement signal processing effect of the present invention. DETAILED DESCRIPTION

[0041] like Figure 1-Figure 5 The method for accurately measuring radar signal parameters in a complex electromagnetic environment includes the following steps:

[0042] Step 1: Use a signal receiver to receive radar signals in a complex electromagnetic environment, digitally sample the received radar signals, calculate the waveform entropy, extract a stable detection waveform sequence, and generate preprocessed detection signal data D 1 ;

[0043] When executing step 1, the specific steps include:

[0044] Step 1-1: Use a signal receiver to receive radar signals in a complex electromagnetic environment and digitally sample the signals;

[0045] Step 1-2: The signal receiver calculates the waveform entropy of the received signal and extracts a stable detection waveform sequence;

[0046] Step 1-3: Generate pre-processed detection signal data D 1 , for use in subsequent steps.

[0047] In this embodiment, the waveform entropy is calculated as follows:

[0048] Waveform entropy is a method to measure signal stability and information entropy, and is used to extract stable waveform sequences from detection signals. The calculation formula is as follows:

[0049]

[0050] Where H is waveform entropy; N is the number of time windows after signal segmentation; p is i The normalized probability density function value of the i-th segment signal is calculated as:

[0051]

[0052] Among them, x i The amplitude of the i-th signal, x j is the amplitude of the jth signal.

[0053] In this embodiment, the extraction of stable detection waveform sequences is based on the waveform entropy threshold setting: if the calculated waveform entropy H is less than the preset threshold (for example, H≤0.3), it indicates that the signal has high stability and is determined to be a valid detection signal. The signals that meet the waveform entropy threshold are sequenced within the time window, and the stable signal sequence with the longest duration is retained as the input for subsequent processing.

[0054] Step 2: The signal receiver processes the pre-processed detection signal data D 1 Perform primary channel division and detect signal data D 1 Divided into multiple channels, the channel detection module performs preliminary detection of frequency, amplitude, phase, pulse width and arrival time of each channel signal;

[0055] If the signal amplitude of at least one channel exceeds the preset threshold value, the signal processing module starts to calculate the phase difference and frequency characteristics of each channel signal and generates a primary frequency measurement value f 1 ;

[0056] When executing step 2, the specific steps include:

[0057] Step 2-1: The signal receiver detects the signal data D 1 Divide into multiple channels, specifically, the detection signal data D 1 It is divided into 256 channels, and the bandwidth of each channel is 9.375MHz.

[0058] Step 2-2: The channel detection module performs preliminary detection of the frequency, amplitude, phase, pulse width and arrival time of each channel signal;

[0059] Step 2-3: If the signal amplitude of at least one channel exceeds the preset threshold value, the signal processing module starts to calculate the phase difference and frequency characteristics of each channel signal to generate a primary frequency measurement value f 1 .

[0060] Step 3: Measure the value f at the primary frequency 1 Under the guidance of , the channel division range is further refined to generate intermediate frequency measurement values;

[0061] When executing step 3, the specific steps include:

[0062] Step 3-1: Measure the value f at the primary frequency 1 Under the guidance of , the signal receiver re-divides the channels and refines the frequency range;

[0063] Step 3-2: The channel detection module detects the amplitude and frequency characteristics of the signal in the channel and generates an intermediate frequency measurement value f 2 ;

[0064] Step 3-3: If the intermediate frequency measurement value f 2 The primary frequency measurement value f 1 If the absolute error is greater than the preset tolerance, the loop continues to step 3.1; otherwise, it goes to step 4.

[0065] Step 4: Under the guidance of the intermediate frequency measurement value, the final accurate frequency measurement value is generated by further refining the channel division and interpolation fitting;

[0066] When executing step 4, the specific steps are as follows:

[0067] Step 4-1: Measure the value f at an intermediate frequency 2 Under the guidance of the signal receiver, the channel division is further refined, and the bandwidth of each channel is reduced to 25kHz;

[0068] Step 4-2: The signal processing module combines the amplitude characteristics of each channel and generates the final accurate frequency measurement value f through interpolation fitting. 3 .

[0069] In this embodiment, the channel is divided into fine parts, and the channel width and frequency range are gradually reduced according to the accuracy requirements of the frequency measurement value. The specific algorithm is as follows:

[0070] Assume that the initial channel bandwidth is B 初始 =9.375MHz, the refined channel bandwidth is B 细化 =B 初始 / K, where K is a refinement ratio coefficient, and in this embodiment, K=10.

[0071] The frequency range is adjusted to the measured value f 中心 ±B refinement / 2.

[0072] Interpolation fitting is used to generate accurate frequency measurement values. It uses a polynomial fitting method to fit the amplitude characteristics of the signal in the channel:

[0073] f(x)=a n x n +a n-1 x n-1 +…+a 0 ;

[0074] By fitting the coefficient a i The least squares solution optimizes the interpolation result.

[0075] The interpolation method is cubic spline interpolation to smoothly interpolate the frequency points of the signal. The specific formula is:

[0076] S i (x) = a i +b i (xx i )+c i (xx i ) 2 +d i (xx i ) 3 ,x i ≤x≤x i + 1 ;

[0077] The coefficient a i ,b i ,c i Solved with boundary conditions and continuity constraints.

[0078] Step 5: Perform error verification on the final frequency measurement value and the previous level measurement value. If the error tolerance requirement is met, the measurement result is reported to the host computer, otherwise it is returned for further processing.

[0079] When executing step 5, the specific steps are as follows:

[0080] Step 5-1: Determine the final accurate frequency measurement value f 3 Whether the absolute error with the previous frequency measurement value is less than the allowable error tolerance;

[0081] Step 5-2: If the error meets the requirements, the frequency measurement result f 3 Report through the host computer, otherwise return to step 4 and continue iteration.

[0082] In this embodiment, the error tolerance requirement is obtained based on the signal sampling rate and the channel bandwidth, specifically:

[0083] Error tolerance

[0084] Wherein, B is the current channel bandwidth; N is the A / D sampling resolution (number of bits); for example, if the channel bandwidth is 25kHz and the sampling resolution is 12 bits, the error tolerance Δf≈6.1Hz, and in this embodiment, Δf=5 can be selected. Represents the set of positive integers.

[0085] In this embodiment, if the current measurement error exceeds the tolerance, the channel division ratio coefficient K and the interpolation fitting times M can be dynamically adjusted:

[0086] For example: K increases by 1 times and the channel width is refined;

[0087] For example: M adds one fitting step to ensure that the interpolation accuracy is improved.

[0088] The following is a specific usage scenario in this embodiment:

[0089] Scenario: Frequency measurement of the enemy's radar signal in a complex electromagnetic environment filled with enemy radar signals and various interference signals. We deploy the equipment of this solution to accurately measure the frequency of specific radar signals.

[0090] Step S1: Signal reception and preprocessing. Specifically, our detection equipment uses a signal receiver to capture the opponent's radar signal. The equipment digitizes the signal and calculates the waveform entropy, extracts a stable waveform sequence from it, and generates preprocessed data D. 1 .

[0091] Step S2: Primary channelization processing, specifically, the receiver converts the data D 1 It is divided into 256 channels, each with a bandwidth of 9.375MHz. When the channel detection module detects that the signal amplitude of a channel exceeds the threshold value, it starts to calculate the primary frequency characteristics of the signal and generates the primary frequency measurement value f 1 .

[0092] Step S3: fine channelization processing, specifically, f 1 = 3.47 GHz as the center, the receiver refines the channel division and reduces the frequency range to ±500 kHz. The channel detection module detects the signal of the refined channel and generates an intermediate frequency measurement value f 2 =3.471GHz.

[0093] Step S4: Advanced channelization processing, specifically, f 2 The channel is further refined, and the bandwidth of each channel is reduced to 25kHz. The signal processing module calculates the precise frequency measurement value f through interpolation fitting. 3 =3.47105GHz.

[0094] Step S5: Result verification and output, specifically comparing f 3 With f 2 The error is 5Hz, which is less than the preset error tolerance of 10Hz. The result is reported to the host computer to determine the frequency characteristics of the opponent's radar and assist in the subsequent electronic jamming deployment.

[0095] The invention discloses a method for accurately measuring radar signal parameters in a complex electromagnetic environment, which solves the technical problem of accurately measuring radar signal parameters in a complex electromagnetic environment. The invention significantly improves the accuracy of frequency measurement by multi-level channel refinement division, gradually optimizes the frequency range, and combines interpolation fitting technology. The invention guides subsequent channel division according to the primary frequency measurement value, realizes rapid response to spectrum changes, has good dynamic adaptability, uses waveform entropy calculation to extract stable detection signals, and sets amplitude thresholds and error tolerances in each level of processing, which effectively improves the recognition ability of target signals. The invention ensures the reliability of the final measurement result through error verification and loop iteration mechanism, and avoids frequency measurement errors caused by signal processing deviations.

Claims

1. A method for accurately measuring radar signal parameters in a complex electromagnetic environment, characterized by: The steps include: Step 1: Use a signal receiver to receive radar signals in a complex electromagnetic environment, digitally sample the received radar signals, calculate waveform entropy, extract a stable detection waveform sequence, and generate preprocessed detection signal data D1; Step 2: The signal receiver performs primary channel division on the pre-processed detection signal data D1, and divides the detection signal data D1 into multiple channels. The channel detection module performs preliminary detection of the frequency, amplitude, phase, pulse width and arrival time of each channel signal; If the signal amplitude of at least one channel exceeds the preset threshold value, the signal processing module starts to calculate the phase difference and frequency characteristics of each channel signal and generates a primary frequency measurement value f1; Step 3: Under the guidance of the primary frequency measurement value f1, the channel division range is further refined to generate the intermediate frequency measurement value; Step 4: Under the guidance of the intermediate frequency measurement value, the final accurate frequency measurement value is generated by further refining the channel division and interpolation fitting; Step 5: Perform error verification on the final frequency measurement value and the previous level measurement value. If the error tolerance requirement is met, the measurement result is reported to the host computer, otherwise it is returned for further processing.

2. The method for accurately measuring radar signal parameters in a complex electromagnetic environment as claimed in claim 1, characterized in that: When executing step 1, the specific steps include: Step 1-1: Use a signal receiver to receive radar signals in a complex electromagnetic environment and digitally sample the signals; Step 1-2: The signal receiver calculates the waveform entropy of the received signal and extracts a stable detection waveform sequence; Step 1-3: Generate pre-processed detection signal data D1 for use in subsequent steps.

3. The method for accurately measuring radar signal parameters in a complex electromagnetic environment as claimed in claim 1, characterized in that: When executing step 2, the specific steps include: Step 2-1: The signal receiver divides the detection signal data D1 into multiple channels, and the bandwidth of each channel is 9.375MHz; Step 2-2: The channel detection module performs preliminary detection of the frequency, amplitude, phase, pulse width and arrival time of each channel signal; Step 2-3: If the signal amplitude of at least one channel exceeds the preset threshold value, the signal processing module starts to calculate the phase difference and frequency characteristics of each channel signal to generate a primary frequency measurement value f1.

4. The method for accurately measuring radar signal parameters in a complex electromagnetic environment as claimed in claim 1, characterized in that: When executing step 3, the specific steps include: Step 3-1: Under the guidance of the primary frequency measurement value f1, the signal receiver re-divides the channels and refines the frequency range; Step 3-2: The channel detection module detects the amplitude and frequency characteristics of the signal in the channel and generates an intermediate frequency measurement value f2; Step 3-3: If the absolute error between the intermediate frequency measurement value f2 and the primary frequency measurement value f1 is greater than the predetermined tolerance, continue to loop to step 3.1; otherwise, proceed to step 4.

5. The method for accurately measuring radar signal parameters in a complex electromagnetic environment as claimed in claim 1, characterized in that: When executing step 4, the specific steps are as follows: Step 4-1: Under the guidance of the intermediate frequency measurement value f2, the signal receiver further refines the channel division, and the bandwidth of each channel is reduced to 25kHz; Step 4-2: The signal processing module combines the amplitude characteristics of each channel and generates the final accurate frequency measurement value f3 through interpolation fitting.

6. The method for accurately measuring radar signal parameters in a complex electromagnetic environment as claimed in claim 4, characterized in that: When executing step 5, the specific steps are as follows: Step 5-1: Determine whether the absolute error between the final accurate frequency measurement value f3 and the previous frequency measurement value is less than the allowable error tolerance; Step 5-2: If the error meets the requirement, the frequency measurement result f3 is reported to the host computer, otherwise return to step 4 and continue iteration.

7. The method for accurately measuring radar signal parameters in a complex electromagnetic environment as claimed in claim 3, characterized in that: When executing step 2-1, the detection signal data D1 is divided into 256 channels.

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