Four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration method and system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING RES INST OF ELECTRONICS TECH
- Filing Date
- 2026-05-14
- Publication Date
- 2026-08-07
AI Technical Summary
[0004]针对现有技术计算量大、校准慢、精度受限的问题，本发明的目的在于提供一种四通道干涉仪测角幅相修正与双模式校准方法及系统，旨在实现低计算量、快校准、高精度测角
有益的效果：本发明提供一种四通道干涉仪测角幅相修正与双模式校准方法及系统，与现有技术相比，具有以下有益效果：（1）计算量小：仅对有效信号做修正，剔除噪声与无效数据，资源占用显著降低；（2）校准快：步进点频循环发射、波门全覆盖，一次校准即可获得全频段系数；（3）精度高：基于信号频点精准匹配修正，通道不一致误差得到最优补偿；（4）工程易实现：流程简化、适配FPGA/DSP实时处理。
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Figure CN122525480A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of digital signal processing technology, and in particular to a method and system for angle and phase correction and dual-mode calibration of a four-channel interferometer. Background Technology
[0002] Interferometer angle measurement relies on the conversion of path difference and phase difference between multiple antenna channels. Inconsistency in amplitude and phase between channels will directly introduce angle measurement error. Traditional solutions usually perform amplitude and phase correction on the entire data segment after AD sampling, and then perform target detection and angle measurement. This has the following drawbacks: (1) Full-time and full-channel correction brings a lot of redundant calculations, high hardware resource consumption, and poor real-time performance; (2) The calibration process is cumbersome, with incomplete frequency coverage or long calibration time; (3) Noise and invalid data participate in the correction, reducing the correction accuracy and angle measurement robustness.
[0003] Currently, there is an urgent need to propose a rapid calibration method and system for interferometer angle measurement to achieve low computational load, fast calibration, and high-precision angle measurement. Summary of the Invention
[0004] To address the problems of high computational load, slow calibration, and limited accuracy in existing technologies, the present invention aims to provide a method and system for angle measurement amplitude and phase correction and dual-mode calibration of a four-channel interferometer, with the goal of achieving low computational load, fast calibration, and high-precision angle measurement.
[0005] To achieve the above objectives, this invention provides a method for angle measurement amplitude and phase correction and dual-mode calibration of a four-channel interferometer, comprising the following steps: Step 1: Synchronous acquisition by analog-to-digital converter: The four-channel analog-to-digital converter samples synchronously and directly performs multiphase filtering and digital channelization without full-band amplitude and phase correction; Step 2: Target detection and IQ truncation of real and imaginary parts of the signal: Perform target detection and effective signal truncation, and take the IQ data of a fixed number of points at the same position in four channels for the detected signal; Step 3: Frequency measurement and Discrete Fourier Transform (DFT) processing: For the detected signal, take the fixed number of IQ data points at the same position in four channels, and perform a Discrete Fourier Transform operation based on the measured frequency of the signal; Step 4: Calibration: Perform statistical fitting on the discrete Fourier transform results to calculate the amplitude and phase correction coefficients, and store the amplitude and phase correction coefficient table according to frequency points; Step 5: Reconnaissance: Perform amplitude and phase correction on the discrete Fourier transform results based on the frequency correction coefficient, and then calculate the target azimuth using the interferometer phase difference algorithm; Step 6: Output the results after angle and phase correction by the four-channel interferometer.
[0006] Furthermore, the calibration in step 4 includes the following steps: Step 4.1: Transmit full-band stepped point frequency signals through the far-field calibration tower to cover the entire detection band and perform cyclic frame skipping; Step 4.2: Set the detection gate to be longer than one transition period to ensure full-frequency target acquisition; Step 4.3: Collect several frames of IQ data at the same fixed number of points in the four channels for each frequency point. After operations including target detection, IQ truncation, and discrete Fourier transform, the amplitude and phase errors of each channel relative to the reference channel are statistically obtained. Step 4.4: Generate and store the amplitude and phase correction coefficient table according to the frequency point index.
[0007] Furthermore, in step 4.1, the full-band stepped point frequency signal is stepped by 10MHz, with a time width of 10μs and a period of 40μs.
[0008] The present invention also provides a four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration system, including an analog-to-digital converter synchronous acquisition module, a target detection and IQ interception unit, a frequency measurement and DFT unit, a calibration mode unit, and a reconnaissance mode unit; The analog-to-digital converter synchronous acquisition module performs synchronous sampling of four-channel analog-to-digital converters and directly performs multi-phase filtering digital channelization without full-band amplitude and phase correction. The target detection and IQ interception unit performs target detection and effective signal interception, and extracts IQ data of a fixed number of points at the same position in four channels for the detected signal; The frequency measurement and DFT unit takes fixed-point IQ data from the same position in four channels for the detected signal and performs a discrete Fourier transform operation based on the measured frequency of the signal. The calibration mode unit performs statistical fitting on the discrete Fourier transform results to calculate the amplitude and phase correction coefficients and stores the amplitude and phase correction coefficient table according to frequency points. The reconnaissance mode unit performs amplitude and phase correction on the discrete Fourier transform results based on the frequency correction coefficient, and then calculates the target azimuth using the interferometer phase difference algorithm.
[0009] Furthermore, the calibration mode unit performs statistical fitting on the discrete Fourier transform results to calculate the amplitude and phase correction coefficients, and stores the amplitude and phase correction coefficients in a table according to frequency points, including the following steps: Step S1: Transmit full-band stepped point frequency signals through the far-field calibration tower to cover the entire detection band and perform cyclic frame skipping; Step S2: Set the detection gate to be greater than one transition period to ensure full-frequency target acquisition; Step S3: Collect several frames of IQ data with a fixed number of points at the same position in four channels for each frequency point. After operations including target detection, IQ truncation, and discrete Fourier transform, the amplitude and phase errors of each channel relative to the reference channel are statistically obtained. Step S4: Generate and store the amplitude and phase correction coefficient table according to the frequency point index.
[0010] Furthermore, in step S1, the full-band stepped point frequency signal is stepped by 10MHz, with a time width of 10μs and a period of 40μs. Beneficial effects: The present invention provides a method and system for angle and phase correction and dual-mode calibration of a four-channel interferometer. Compared with the prior art, it has the following beneficial effects: (1) Small computational load: only valid signals are corrected, noise and invalid data are eliminated, and resource consumption is significantly reduced; (2) Fast calibration: step-frequency cyclic transmission and full gate coverage, the coefficients of the entire frequency band can be obtained in one calibration; (3) High accuracy: based on the precise matching correction of signal frequency points, the channel inconsistency error is optimally compensated; (4) Easy to implement in engineering: the process is simplified and adapted to FPGA / DSP real-time processing. Attached Figure Description
[0011] Figure 1 This is a block diagram of the architecture of the four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration system involved in the embodiments of the present invention; Figure 2 This is a flowchart of the calibration mode involved in the embodiments of the present invention; Figure 3 This is a flowchart of the reconnaissance mode involved in the embodiments of the present invention. Detailed Implementation
[0012] The preferred mechanisms and implementation methods of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0013] In signal processing and digital computing, DFT stands for Discrete Fourier Transform, used to transform discrete-time signals from the time domain to the frequency domain. DFT is a core tool in digital signal processing, capable of analyzing the spectral characteristics of signals, and is commonly used in speech processing, image processing, and communication systems. DFT obtains complex coefficients in the frequency domain by sampling and calculating discrete signals, thereby enabling frequency analysis of the signal.
[0014] An analog-to-digital converter (A / D converter) is a front-end device that converts analog signals into digital signals for processing by subsequent digital devices. The A / D converter transforms a continuous-time, continuous-amplitude analog signal into a discrete-time, discrete-amplitude digital signal. A / D conversion typically involves four processes: sampling, holding, quantization, and encoding. In practical circuits, sampling and holding, quantization, and encoding are often performed simultaneously.
[0015] In wireless communication and digital signal processing, IQ refers to the in-phase (I) and quadrature (Q) components. They are two orthogonal components that represent a signal in complex form and are used to describe the amplitude and phase information of the signal.
[0016] The I component corresponds to the amplitude of the reference carrier (usually a cosine wave), and the Q component corresponds to the amplitude of a sine wave that is 90° out of phase with the reference carrier. By combining I and Q, signals with arbitrary phase and amplitude can be represented in a two-dimensional plane (IQ plane).
[0017] The core principle is that during modulation, the baseband signal is divided into I and Q paths, which are multiplied by carrier waves (cos and sin) that are 90° out of phase, and then added together to generate the modulated signal. During demodulation, the receiver mixes the signal with the same cos and sin signals, and then extracts the I and Q components through a low-pass filter, thereby recovering the original baseband signal.
[0018] Example 1: As Figures 1 to 3 As shown in the figure, the present invention discloses a technical solution for a method and system for angle and phase correction and dual-mode calibration of a four-channel interferometer. Figure 1 This is a block diagram of the architecture of the four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration system involved in the embodiments of the present invention; Figure 2 This is a flowchart of the calibration mode involved in the embodiments of the present invention; Figure 3 This is a flowchart of the reconnaissance mode involved in the embodiments of the present invention.
[0019] This invention provides a method for angle measurement amplitude and phase correction and dual-mode calibration of a four-channel interferometer, comprising the following steps: Step 1: Synchronous acquisition by analog-to-digital converter: The four-channel analog-to-digital converter samples synchronously and directly performs multiphase filtering and digital channelization without full-band amplitude and phase correction; Step 2: Target detection and IQ truncation of real and imaginary parts of the signal: Perform target detection and effective signal truncation, and take the IQ data of a fixed number of points at the same position in four channels for the detected signal; Step 3: Frequency measurement and Discrete Fourier Transform (DFT) processing: For the detected signal, take the fixed number of IQ data points at the same position in four channels, and perform a Discrete Fourier Transform operation based on the measured frequency of the signal; Step 4: Calibration: Perform statistical fitting on the discrete Fourier transform results to calculate the amplitude and phase correction coefficients, and store the amplitude and phase correction coefficient table according to frequency points; The calibration in step 4 includes the following steps: Step 4.1: Transmit full-band stepped point frequency signals through the far-field calibration tower, with a step of 10MHz, a time width of 10μs, and a period of 40μs, to cover the entire detection frequency band and cyclically skip frames; Step 4.2: Set the detection gate to be greater than one transition period to ensure full-frequency target acquisition; the full-frequency step frequency signal is a part of the full-frequency signal, meaning that all signals in the covered frequency band can be acquired; Step 4.3: Collect several frames of IQ data at the same fixed number of points in the four channels for each frequency point. After operations including target detection, IQ truncation, and discrete Fourier transform, the amplitude and phase errors of each channel relative to the reference channel are statistically obtained. Step 4.4: Generate and store the amplitude and phase correction coefficient table according to the frequency point index.
[0020] Step 5: Reconnaissance: Perform amplitude and phase correction on the discrete Fourier transform results based on the frequency correction coefficient, and then calculate the target azimuth using the interferometer phase difference algorithm; Step 6: Output the results after angle and phase correction by the four-channel interferometer.
[0021] Example 2: This embodiment of the invention provides a four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration system, including an analog-to-digital converter synchronous acquisition module, a target detection and IQ interception unit, a frequency measurement and DFT unit, a calibration mode unit, and a reconnaissance mode unit; The analog-to-digital converter synchronous acquisition module performs synchronous sampling of the four-channel analog-to-digital converter and directly performs multiphase filtering and digital channelization without full-band amplitude and phase correction.
[0022] The target detection and IQ interception unit performs target detection and effective signal interception, and extracts IQ data of a fixed number of points at the same position in four channels from the detected signal.
[0023] The frequency measurement and DFT unit takes fixed-point IQ data from the same location on four channels for the detected signal and performs a discrete Fourier transform operation based on the measured frequency of the signal.
[0024] The calibration mode unit performs statistical fitting on the discrete Fourier transform results to calculate the amplitude and phase correction coefficients, and stores the amplitude and phase correction coefficient table according to frequency points.
[0025] The calibration mode unit performs statistical fitting on the discrete Fourier transform results to calculate the amplitude and phase correction coefficients, and stores the amplitude and phase correction coefficients in a table according to frequency points, including the following steps: Step S1: Transmit full-band stepped point frequency signals through the far-field calibration tower, with a step of 10MHz, a time width of 10μs, and a period of 40μs, to cover the entire detection frequency band and cyclically skip frames; Step S2: Set the detection gate to be greater than one transition period to ensure full-frequency target acquisition; the full-frequency step frequency signal is a part of the full-frequency signal, meaning that all signals in the covered frequency band can be acquired; Step S3: Collect several frames of IQ data with a fixed number of points at the same position in four channels for each frequency point. After operations including target detection, IQ truncation, and discrete Fourier transform, the amplitude and phase errors of each channel relative to the reference channel are statistically obtained. Step S4: Generate and store the amplitude and phase correction coefficient table according to the frequency point index.
[0026] The reconnaissance mode unit performs amplitude and phase correction on the discrete Fourier transform results based on the frequency correction coefficient, and then calculates the target azimuth using the interferometer phase difference algorithm.
[0027] This invention provides a method and system for angle and phase correction and dual-mode calibration of a four-channel interferometer. It corrects only the valid signal, eliminates noise and invalid data, and significantly reduces resource consumption. It features step-frequency cyclic transmission and full gate coverage, allowing full-band coefficients to be obtained in a single calibration. Based on precise signal frequency matching correction, channel inconsistency errors are optimally compensated. The process is simplified, adaptable to FPGA / DSP real-time processing, and easy to implement in engineering.
[0028] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for angle and phase correction and dual-mode calibration of a four-channel interferometer, characterized in that, Includes the following steps: Step 1: Synchronous acquisition by analog-to-digital converter: The four-channel analog-to-digital converter samples synchronously and directly performs multiphase filtering and digital channelization without full-band amplitude and phase correction; Step 2: Target detection and IQ truncation of real and imaginary parts of the signal: Perform target detection and effective signal truncation, and take the IQ data of a fixed number of points at the same position in four channels for the detected signal; Step 3: Frequency measurement and Discrete Fourier Transform (DFT) processing: For the detected signal, take the fixed number of IQ data points at the same position in four channels, and perform a Discrete Fourier Transform operation based on the measured frequency of the signal; Step 4: Calibration: Perform statistical fitting on the discrete Fourier transform results to calculate the amplitude and phase correction coefficients, and store the amplitude and phase correction coefficient table according to frequency points; Step 5: Reconnaissance: Perform amplitude and phase correction on the discrete Fourier transform results based on the frequency correction coefficient, and then calculate the target azimuth using the interferometer phase difference algorithm; Step 6: Output the results after angle and phase correction by the four-channel interferometer.
2. The four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration method according to claim 1, characterized in that, The calibration in step 4 includes the following steps: Step 4.1: Transmit full-band stepped point frequency signals through the far-field calibration tower to cover the entire detection band and perform cyclic frame skipping; Step 4.2: Set the detection gate to be longer than one transition period to ensure full-frequency target acquisition; Step 4.3: Collect several frames of IQ data at the same fixed number of points in the four channels for each frequency point. After operations including target detection, IQ truncation, and discrete Fourier transform, the amplitude and phase errors of each channel relative to the reference channel are statistically obtained. Step 4.4: Generate and store the amplitude and phase correction coefficient table according to the frequency point index.
3. The four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration method according to claim 2, characterized in that, In step 4.1, the full-band stepped point frequency signal is stepped at 10MHz, with a time width of 10μs and a period of 40μs.
4. A four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration system, characterized in that, Includes an analog-to-digital converter synchronous acquisition module, a target detection and IQ interception unit, a frequency measurement and DFT unit, a calibration mode unit, and a reconnaissance mode unit; The analog-to-digital converter synchronous acquisition module performs synchronous sampling of four-channel analog-to-digital converters and directly performs multi-phase filtering digital channelization without full-band amplitude and phase correction. The target detection and IQ interception unit performs target detection and effective signal interception, and extracts IQ data of a fixed number of points at the same position in four channels for the detected signal; The frequency measurement and DFT unit takes fixed-point IQ data from the same position in four channels for the detected signal and performs a discrete Fourier transform operation based on the measured frequency of the signal. The calibration mode unit performs statistical fitting on the discrete Fourier transform results to calculate the amplitude and phase correction coefficients and stores the amplitude and phase correction coefficient table according to frequency points. The reconnaissance mode unit performs amplitude and phase correction on the discrete Fourier transform results based on the frequency correction coefficient, and then calculates the target azimuth using the interferometer phase difference algorithm.
5. The four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration system according to claim 4, characterized in that, The calibration mode unit performs statistical fitting on the discrete Fourier transform results to calculate the amplitude and phase correction coefficients, and stores the amplitude and phase correction coefficients in a table according to frequency points, including the following steps: Step S1: Transmit full-band stepped point frequency signals through the far-field calibration tower to cover the entire detection band and perform cyclic frame skipping; Step S2: Set the detection gate to be greater than one transition period to ensure full-frequency target acquisition; Step S3: Collect several frames of IQ data with a fixed number of points at the same position in four channels for each frequency point. After operations including target detection, IQ truncation, and discrete Fourier transform, the amplitude and phase errors of each channel relative to the reference channel are statistically obtained. Step S4: Generate and store the amplitude and phase correction coefficient table according to the frequency point index.
6. The four-channel interferometer angle measurement amplitude and phase correction and dual-mode calibration system according to claim 5, characterized in that, In step S1, the full-band stepped point frequency signal is stepped by 10MHz, with a time width of 10μs and a period of 40μs.