An iterative feedback-based burst signal progressive angle measurement method

Abstract

The application provides a burst signal progressive angle measurement method based on iterative feedback, which controls two independent beams of a phased array antenna to search signals in a space range, obtains angle information with maximum energy accumulation value, uses the angle information as an initial iterative point of angle measurement, controls the double beams to code at symmetrical points with 3dB beam width interval in the pitch direction of the point, performs a power difference measurement, then codes at symmetrical points with 3dB beam width interval in the azimuth direction, performs a power difference measurement, combines pre-stored two-dimensional calibration data, calculates an azimuth angle and a pitch angle of a target point, uses the result as an input direction of next measurement, forms a closed loop iteration in a direction finding period until the angle difference is less than a preset angle measurement error threshold, and outputs a final angle measurement result. The angle measurement method provided by the application can complete a coding angle measurement in μs, and can complete multiple angle measurements in a burst period.

Description

Technical Field

[0001] This invention relates to the field of measurement and testing technology, and specifically to a progressive angle measurement method based on iterative feedback burst signals. Background Technology

[0002] Burst signals, with their characteristics of high instantaneous transmission power, time-division multiple access, and large bandwidth, offer high channel resource utilization and strong communication security, making them widely used in satellite communication systems, mobile communication systems, emergency communication systems, radar, and other systems. However, the inherent instantaneousness, frequency uncertainty, non-cooperative nature, and low observability of burst signals directly conflict with the continuity and accumulation prerequisites upon which traditional angle measurement algorithms rely, posing significant challenges to angle measurement technology.

[0003] Traditional angle measurement relies on sampling and processing a continuous signal, using the statistical characteristics of a large number of samples to accurately estimate the direction of arrival (DOA). However, burst signals are short-lived (potentially only milliseconds or even microseconds), resulting in a very limited number of signal samples that can be captured. This leads to insufficient energy accumulation, deteriorates the DOA signal-to-noise ratio, increases the probability of phase ambiguity, causes aperture ambiguity, and results in abrupt changes in the angle measurement. Furthermore, the angle measurement system must complete the entire process of "signal detection" → "parameter estimation" → "angle calculation" within an extremely short time. This places higher demands on how to capture burst signals and complete parameter angle measurement within such a short timeframe. Therefore, there is an urgent need to develop efficient and high-precision angle measurement methods for burst signals.

[0004] Chinese Patent Publication No. CN 105974389A, published on September 28, 2016, entitled "A Single-Pulse Angle Measurement Method for Mechanically Scanned Meter-Wave Radar Based on Iterative Processing," describes a method that reduces the impact of noise on the signal and decreases angle measurement errors. The method primarily involves uniformly dividing the antenna into two subarrays, transmitting pulse signals, coherently accumulating the received echo signals to obtain the accumulated data, performing phase adjustment on the received echo signals, and finding the angle value corresponding to the pulse. Two angles are taken evenly to the left and right of this angle, and the corresponding amplitudes are found, thus obtaining two new sets of data. From these two sets of data, the sum and difference beams are obtained. Sum and difference beam monopulse angle measurement is performed on the sum and difference beams to obtain the target's off-axis angle. The off-axis angle is then assigned to... Repeat the above steps until the estimated angle of the target meets the preset error condition. Although it can perform iterative improvement of angle measurement accuracy, it is designed for continuous wave radar signals and requires a large number of pulses to achieve a high signal-to-noise ratio. At the same time, the sum-difference beam angle measurement method used is suitable for high-precision target tracking applications such as active detection.

[0005] Therefore, an efficient angle measurement method for sudden signals is needed. Summary of the Invention

[0006] This invention addresses the problems of low single-shot angle measurement accuracy and the imbalance between accuracy and system / computational complexity in precise direction finding of burst signals. It provides a progressive angle measurement method for burst signals based on iterative feedback. This method calculates the angle by sequentially measuring the power difference in the azimuth and elevation planes. Through continuous iteration, the angle measurement error is reduced to meet accuracy requirements. This invention transforms an open-loop, one-shot angle measurement process into a closed-loop, progressive self-feedback angle measurement system. It achieves a balance between angle measurement performance, system construction cost, and complexity, resulting in high engineering feasibility.

[0007] This invention provides a progressive angle measurement method for burst signals based on iterative feedback. When a burst signal is detected, the first and second beams of a dual-beam phased array antenna are controlled to perform a spatial signal search within the spatial domain along a preset path. The beam position where the cumulative power value is maximized is used as the initial estimated angle. ; Control the first and second beams to fix the azimuth angle In the pitch direction Symmetrical point coding is performed with the center as the center and half-beamwidth as the interval to obtain the elevation power difference. ,in, ; Control the first and second beams to fix the elevation angle In terms of direction Using a center and a half-beamwidth as the center, symmetrical point coding is performed to obtain the azimuth power difference. ; according to , The target point azimuth of the burst signal is calculated by solving the pre-stored two-dimensional pitch / azimuth calibration data. and pitch angle ,Will and This direction serves as the input for the next iteration measurement until the angle change between two iterations is less than a preset angle measurement error threshold or the maximum number of iterations is reached. N max Output the final angle measurement result.

[0008] The incremental angle measurement method based on iterative feedback for burst signals described in this invention, as a preferred embodiment, includes the following steps: S1. Beam pointing calibration of dual-beam phased array antenna is performed in anechoic environment to obtain elevation power difference calibration curve and azimuth power difference calibration curve. The elevation power difference calibration curve and azimuth power difference calibration curve are two-dimensional elevation / azimuth calibration data. S2. Based on a preset threshold, detect whether there is a sudden signal. The dual-beam phased array antenna measures and compares the cumulative power values ​​of different wave positions within the spatial domain according to a preset path, and obtains the angle information of the wave position with the maximum cumulative power value as the initial estimated angle. ; S3. Angle measurement initialization: Set the angle measurement error threshold. Maximum number of iterations Convergence factor The number of iterations i Initialize to 1; S4, the i Secondary elevation plane angle measurement: This ensures that both beams of the dual-beam phased array antenna have fixed azimuth angles. Fixed directions in the pitch direction , Beamcoding is performed to obtain the elevation power difference between the first and second beams. The pitch angle correction amount is obtained by querying the pitch angle power difference calibration curve. ,in, The elevation angle is the angle at which the signal attenuation of the dual-beam phased array antenna is 3dB. No. i Secondary azimuth plane angle measurement: This ensures that both beams of the dual-beam phased array antenna have fixed elevation angles. The directions are fixed upwards. , Beamcoding is performed to obtain the azimuth power difference between the first and second beams. The azimuth correction amount is obtained by querying the azimuth power difference calibration curve. ,in, The azimuth angle when the signal attenuation of the dual-beam phased array antenna is 3dB. Update angle estimation values: ; S5. Obtain the angle change after two iterations: ; Perform convergence judgment: if ,but i = i +1, to determine the iteration count. If yes, return to step S4 to continue iterating; otherwise, terminate the iteration and output the current best estimate. ; if If the iteration converges, the final angle measurement result will be output. .

[0009] In the preferred embodiment of the progressive angle measurement method for burst signals based on iterative feedback described in this invention, in step S1, the dual-beam phased array antenna is fixed on a two-dimensional turntable in an anechoic chamber, and the two-dimensional turntable is adjusted so that the normal of the antenna array surface of the dual-beam phased array antenna is aligned with the direction of the standard horn signal source, and the elevation angle power difference calibration curve and the azimuth angle power difference calibration curve are measured. The measurement method for the pitch angle power difference calibration curve is as follows: The angle between the two beams pointing in the pitch direction is set to one and a half power beamwidths. A standard horn signal source transmits a continuous wave signal at a fixed frequency and power. A two-dimensional turntable scans within the coverage area in the pitch direction with fixed steps. At each scanning angle position, the received power values ​​of the two beam channels are simultaneously recorded and subtracted to obtain the pitch angle received power difference ΔP_E. The angle of the two-dimensional turntable corresponding to the zero pitch angle received power difference in the pitch calibration data is the pitch iso-signal axis direction. The absolute angle of the two-dimensional turntable at each calibration point is subtracted from the pitch iso-signal axis angle to obtain the angle deviation Δθ relative to the pitch iso-signal axis. The pitch angle power difference calibration curve is obtained by plotting Δθ as the abscissa and the pitch angle received power difference ΔP_E as the ordinate. The measurement method for the azimuth power difference calibration curve is as follows: The angle between the two beams pointing in the azimuth direction is set to one and a half power beamwidths. A standard horn signal source transmits a continuous wave signal at a fixed frequency and power. A two-dimensional turntable scans within the coverage area in the azimuth direction with fixed steps. At each scanning angle position, the received power values ​​of the two beam channels are recorded simultaneously and the difference is calculated to obtain the azimuth received power difference ΔP_A. The two-dimensional turntable angle corresponding to the zero azimuth received power difference in the azimuth calibration data is the azimuth iso-signal axis direction. The absolute angle of the two-dimensional turntable at each calibration point is subtracted from the azimuth iso-signal axis angle to obtain the angular deviation Δφ relative to the azimuth iso-signal axis. The azimuth power difference calibration curve is obtained by plotting Δφ as the abscissa and ΔP_A as the ordinate. The fixed step is 1 / 50 to 1 / 100 of the beamwidth.

[0010] The incremental angle measurement method for burst signals based on iterative feedback described in this invention, as a preferred embodiment, in step S2, the beam scanning range of the dual-beam phased array antenna is ±θ, according to... The circular beam is discretized within the ±θ range to obtain the scanning wave position; During the initial search angle estimation process, based on the scanning range of the dual-beam phased array antenna and the 3dB beamwidth, the scanning range is discretized into multiple regularly arranged wave points according to the beamwidth. Each wave point corresponds to an angle in the spatial position. The dual-beam phased array antenna is controlled to point to each wave point in sequence, and the signal power value of each wave point is measured. The power values ​​of each wave point are compared, and the angle information of the wave point with the largest cumulative power value is used as the initial estimated angle.

[0011] In the progressive angle measurement method for burst signals based on iterative feedback described in this invention, as a preferred embodiment, in step S2, the beam scanning range of the dual-beam phased array antenna is ±60°. , The scan wave position is 60 rows.

[0012] The incremental angle measurement method based on iterative feedback for burst signals described in this invention, as a preferred embodiment, includes step S3, It is 10. k It is a constant.

[0013] The incremental angle measurement method based on iterative feedback for burst signals described in this invention, as a preferred embodiment, includes step S3, The setting range is .

[0014] In the progressive angle measurement method for burst signals based on iterative feedback described in this invention, as a preferred embodiment, in step S4, when measuring the pitch angle, the pointing angle of the first beam is... The pointing angle of the second beam is ; When measuring the azimuth, the pointing angle of the first beam is: The pointing angle of the second beam is .

[0015] The incremental angle measurement method based on iterative feedback for burst signals described in this invention, as a preferred embodiment, includes step S4, ; ; in, For the first beam i The cumulative value of the pitch plane angle measurement power in each iteration. For the second beam i The cumulative value of the pitch plane angle measurement power in each iteration. For the first beam i The cumulative value of the azimuth surface angular power in each iteration. For the second beam i The cumulative value of the azimuth surface angular power in each iteration.

[0016] The burst signal progressive angle measurement method based on iterative feedback described in this invention, as a preferred embodiment, uses a dual-beam angle measurement system comprising: a dual-beam phased array antenna and a signal receiving and processing device; The dual-beam phased array antenna includes a beam control unit, N active phased arrays, a passive combining network connected to all the active phased arrays, and a power supply unit for power supply. The signal receiving and processing equipment includes a system control module, a frequency conversion channel connected to the system control module, an acquisition and processing unit, and a power supply unit for the signal receiving and processing equipment. The frequency conversion channel performs signal amplification, filtering, and down-conversion, while the acquisition and processing unit performs signal acquisition, signal detection, and angle measurement processing. The passive synthesizer outputs the first and second beams to the frequency conversion channel. The first and second beams are two independently controlled beams.

[0017] This invention employs iterative amplitude-to-angle measurement, resulting in a simpler system composition and lower data processing computation, making it suitable for capturing and determining the direction of short-duration, burst communication signals.

[0018] This invention provides a method and system that employs an iterative feedback control strategy to asymptotically approximate the true signal angle of arrival through cyclic testing to satisfy the angle measurement error.

[0019] This invention first detects the received signal. Since it deals with burst signals, which are short in duration and have randomly varying burst lengths, the number of sample points required for angle measurement is insufficient, leading to a deterioration in the signal continuity and energy accumulation relied upon by traditional angle measurement algorithms. Therefore, this method controls two independent beams of a phased array antenna to search for signals in the spatial domain along a preset path. It compares the accumulated energy values ​​detected at different locations. Through one round of searching, the angle information with the largest accumulated energy value is obtained. This angle information is used as the initial iteration point for angle measurement. The dual beams are then used to mark symmetrical points at 3dB beamwidth intervals in the elevation direction at this point to measure the power difference. Subsequently, symmetrical points at 3dB beamwidth intervals are marked in the azimuth direction to measure the power difference again. Combined with pre-stored two-dimensional calibration data, the azimuth and elevation angles of a target point are calculated. This result is used as the input direction for the next measurement, forming a closed-loop iteration within one direction-finding cycle until the measured angle difference is less than a preset angle measurement error threshold, at which point the final angle measurement result is output.

[0020] The angle measurement method proposed in this invention completes one coding angle measurement in the order of μs and can complete multiple angle measurements within a single burst cycle. Compared with other angle measurement systems, it features low system complexity, low data processing computation, and strong adaptability to burst signals. The advantage of this method lies not in surpassing absolute performance, but in the balance between performance, cost, and complexity, exchanging acceptable performance sacrifices for the possibility and convenience of engineering implementation.

[0021] A progressive angle measurement method for burst signals based on iterative feedback includes the following steps: using dual-beam coding and iterative feedback processing to achieve progressive convergence of angle measurement results within a short period. The specific implementation steps are as follows: (1) Beam pointing calibration of the dual-beam phased array was performed in an anechoic environment. The dual-beam phased array antenna was fixed on a two-dimensional turntable, and the turntable was adjusted so that the antenna array normal was aligned with the direction of the standard horn signal source. First, the elevation power difference calibration curve was measured: the two beam pointing angles were set to one and a half power beamwidths in the elevation direction. The standard horn signal source emitted a continuous wave signal at a fixed frequency and power. The turntable scanned the coverage area in the elevation direction with a fixed step (usually 1 / 50 to 1 / 100 of the beamwidth). At each scanning angle position, the received power values ​​of the two beam channels were recorded simultaneously, and the difference ΔP_E = P1 – P2 was calculated. The turntable angle corresponding to the zero power difference (ΔP_E = 0) in the calibration data was determined as the iso-signal axis direction. The absolute angle of the turntable at each calibration point was subtracted from the iso-signal axis angle to convert it into an angle deviation Δθ relative to the iso-signal axis. Plotting Δθ as the abscissa and the power difference as the ordinate, we obtain the pitch angle power difference calibration curve ΔP_E = f_E(Δθ).

[0022] (2) Measurement of azimuth power difference calibration curve: Set two beams pointing at an angle of one and a half power beamwidths in the azimuth direction. A standard horn signal source transmits a continuous wave signal at a fixed frequency and power. The turntable scans within the coverage area in the azimuth direction at a fixed step (usually 1 / 50 to 1 / 100 of the beamwidth). At each scanning angle position, the received power values ​​of the two beam channels are recorded simultaneously, and the difference ΔP_A = P1 – P2 is calculated. The turntable angle corresponding to the zero power difference (ΔP_A = 0) in the calibration data is determined as the iso-signal axis direction. The absolute angle of the turntable at each calibration point is subtracted from the iso-signal axis angle to convert it into an angular deviation Δφ relative to the iso-signal axis. With Δφ as the abscissa and the power difference as the ordinate, the azimuth power difference calibration curve ΔP_A = f_A(Δφ) is obtained.

[0023] The above-mentioned calibration method based on measured data has internalized the inherent beam pointing deviation and inconsistent channel gain of the dual-beam antenna system into the calibration curve, eliminating the need for compensation from the back-end direction-finding algorithm.

[0024] (3) To detect the presence or absence of a signal, it is necessary to determine the initial search angle. Based on the scanning range and 3dB beamwidth of the front-end phased array antenna, the scanning range is discretized into multiple regularly arranged wave points according to the beamwidth. Each wave point corresponds to an angle in space. The phased array antenna is controlled to point to each wave point in sequence, and the signal power value of each wave point is measured. The power values ​​of each wave point are compared, and the angle corresponding to the wave point with the largest cumulative power value is the initial search angle. .

[0025] (4) Set the angle measurement error threshold to , usually set to .

[0026] (5) Set the maximum number of iterations It is usually taken as 5 to 10 times.

[0027] (6) Set the convergence factor The value ranges from 0.5 to 0.8.

[0028] (7) Pitch angle measurement: Control the dual-beam antenna to fix its azimuth direction to the current azimuth angle. In the pitch plane, using the current pitch angle estimate. Centered on, according to half-power beamwidth Two beams are symmetrically arranged at intervals, meaning the elevation directions of the two beams are respectively... , Pitch beam mapping Figure 3 As shown. Under this pointing configuration, the power values ​​of the burst signal were measured, and the power values ​​of the two beams were obtained as follows: , The power difference is .

[0029] (8) Azimuth plane angle measurement: Control the dual-beam antenna to fix its direction in the elevation direction to the current elevation angle. In the azimuth plane, using the current pitch angle estimate. Centered on, according to half-power beamwidth Two beams are symmetrically arranged at intervals, meaning the azimuth directions of the two beams are respectively... , Azimuth beamforming, such as Figure 4 As shown. Under this pointing configuration, the power values ​​of the burst signal were measured, and the power values ​​of the two beams were obtained as follows: , The power difference is .

[0030] (9) Based on the power difference measured by the pitch direction The pitch angle correction amount can be obtained by querying the pitch angle power difference calibration curve. ; (10) Based on the power difference measured by azimuth. The azimuth correction amount is obtained by querying the azimuth power difference calibration curve. ; (11) Update the angle estimation value based on the correction result: ; (12) Calculate the angle change between the two iterations: ; if If the iteration converges, the final angle measurement result will be output. ; if And the number of iterations Then For the new estimate, repeat steps (7) to (12).

[0031] If the number of iterations reaches If convergence is still not achieved, the iteration is terminated and the current best estimate is output.

[0032] The present invention has the following advantages: (1) This invention ensures that the system can converge to the true value within a small number of iterations by using the optimal beam spacing configuration and the design of the adaptive convergence factor, which is particularly suitable for rapid and accurate direction finding of burst signals.

[0033] (2) The present invention adopts a relatively simple dual-beam hardware architecture, and combines signal processing algorithm and system control algorithm to achieve high-precision direction finding. It achieves a relative balance between system complexity and measurement accuracy, and has a high degree of engineering implementation.

[0034] (3) The system of the present invention is robust. Even if there is a large error in the initial angle estimation or the signal-to-noise ratio is low, the system can still gradually converge to the correct result through iteration, showing good stability. Attached Figure Description

[0035] Figure 1 This is a flowchart of a burst signal-based progressive angle measurement method based on iterative feedback; Figure 2 A block diagram of a dual-beam angle measurement system based on a burst signal progressive angle measurement method with iterative feedback; Figure 3 A schematic diagram of dual-beam coding on the elevation plane for a burst signal progressive angle measurement method based on iterative feedback; Figure 4 A schematic diagram of dual-beam coding on the azimuth plane for a progressive angle measurement method based on iterative feedback burst signals; Figure 5 This is a schematic diagram of the initial search angle estimation scanning path for a progressive angle measurement method based on iterative feedback burst signals. Figure 6 This is a schematic diagram illustrating the iterative convergence of an angle estimation method based on iterative feedback and a progressive angle measurement method using burst signals. Figure 7 This is a schematic diagram illustrating the iterative convergence of angle measurement error in a burst signal-based progressive angle measurement method based on iterative feedback.

[0036] Figure label: 1. Dual-beam phased array antenna; 11. Beam control unit; 12. Active phased array subarray; 13. Passive synthesizer network; 14. Power supply unit; 2. Signal receiving and processing equipment; 21. System control module; 22. Frequency conversion channel; 23. Acquisition and processing unit; 24. Power supply unit for signal receiving and processing equipment. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Example 1

[0038] like Figures 1-7 As shown, a burst signal-based progressive angle measurement method based on iterative feedback includes the following steps: S1, such as Figure 1 As shown, the dual-beam angle measurement system of the present invention includes the following components: Independently controllable dual-beam phased array antenna 1, used for receiving target radio signals; Signal receiving and processing device 2 is used for signal amplification, filtering, down-conversion, signal detection, and other processing. The dual-beam phased array antenna 1 includes a beam control unit 11, N active phased arrays 12, a passive combining network 13 connected to all the active phased arrays 12, and a power supply unit 14 for power supply. The signal receiving and processing device 2 includes a system control module 21, a frequency conversion channel 22 connected to the system control module 21, an acquisition and processing unit 23, and a power supply unit 24 for powering the signal receiving and processing device. The frequency conversion channel 22 performs signal amplification, filtering, and down-conversion, and the acquisition and processing unit 23 performs signal acquisition, signal detection, and angle measurement processing. The passive synthesizer network 14 outputs a first beam and a second beam to the frequency conversion channel 22. The first beam and the second beam are two independently controlled beams.

[0039] Beam pointing calibration of dual-beam phased array antenna 1 was performed in an anechoic environment, and elevation power difference calibration curve and azimuth power difference calibration curve were obtained respectively. To detect the presence or absence of a signal, the initial search angle needs to be determined. Based on the scanning range and 3dB beamwidth of the front-end phased array antenna, the scanning range is discretized into multiple regularly arranged wave points according to the beamwidth. Each wave point corresponds to an angle in space. The phased array antenna is controlled to point sequentially at each wave point, and the signal power value is measured at each wave point. The power values ​​of each wave point are compared, and the angle corresponding to the wave point with the largest cumulative power value is taken as the initial search angle. .

[0040] S2. During the on-orbit phase, a sudden signal is detected. An angle measurement is performed on a ground target that emitted the sudden signal, with an angle measurement accuracy of 0.05° required.

[0041] Given that the beam scanning range of the dual-beam phased array antenna 1 is ±60°, and the azimuth direction... Looking up and down Discretizing the ±60° range using a 2°*2° circular beam pattern results in 60 rows of scanning wave positions, as shown below. Figure 5 As shown.

[0042] During the initial search angle estimation process, the dual-beam phased array antenna 1 is controlled to scan from top to bottom and from left to right. After the previous row is scanned, the beam points to the next row and continues scanning from left to right. Power values ​​are measured at each wave position until all 60 rows of wave positions are scanned. The power values ​​at each wave position are compared, and the angle value corresponding to the wave position with the maximum signal power is obtained as the initial search angle. The obtained initial search angles are azimuth 85.0° and elevation 42.0°.

[0043] S3. Initialization Settings: Initial estimate: ; Error threshold: ; Maximum number of iterations: ; Convergence factor: ; Antenna half-power beamwidth: azimuth Looking up and down ; S4, First Iteration i Initialize to 1; Pitch plane measurement: Centered at 42.0°, with the beam pointing at (85.0°, 41.0°) and (85.0°, 43.0°), the power difference was measured. ; Azimuth measurement: Centered at 85.0°, the beam points to (84.0°, 42.0°) and (86.0°, 42.0°), and the power difference is measured. ; Data fusion and querying the calibration curve yielded: ; Angle Update: ; S5. Convergence Judgment: ; If the accuracy requirement is not met, continue iterating.

[0044] i = i + 1, return to step S4 for the second iteration: Continue the measurement with (84.50°, 40.66°) as the new measurement center; Elevation plane measurement: Centered at 40.66°, the beam points at (83.50°, 40.66°) and (85.50°, 40.66°), and the power difference is measured. ; Azimuth measurement: Centered at 84.50°, the beam points at (84.50°, 39.66°) and (84.50°, 41.66°), and the power difference is measured. ; Data fusion and querying the calibration curve yielded: ; Angle Update: ; Convergence criteria: ; If the accuracy requirement is not met, continue iterating.

[0045] S6. Repeat the angle measurement process. After 7 iterations, the total error is... The accuracy requirements are met, and the final angle measurement results (83.53°, 43.26°) are output. The angle convergence process is as follows: Figure 6 As shown, the total angle measurement error is: ; The convergence process of angle measurement error is as follows Figure 7 As shown.

[0046] The target's true direction in this embodiment is (83.5°, 43.3°), and the required angle measurement accuracy is 0.2°. This embodiment achieves the target.

[0047] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A progressive angle measurement method based on iterative feedback burst signals, characterized in that: When a burst signal is detected, the first and second beams of the dual-beam phased array antenna (1) are controlled to perform a spatial signal search within the spatial domain along a preset path, using the position of the maximum cumulative power value as the initial estimated angle. ; Control the fixed azimuth angle of the first beam and the second beam In the pitch direction Symmetrical point coding is performed with the center as the center and half-beamwidth as the interval to obtain the elevation power difference. ,in, ; Control the first beam and the second beam to fix the elevation angle In terms of direction Using a center and a half-beamwidth as the center, symmetrical point coding is performed to obtain the azimuth power difference. ; according to , The target point azimuth of the burst signal is calculated by solving the pre-stored two-dimensional pitch / azimuth calibration data. and pitch angle ,Will and This direction serves as the input for the next iteration measurement until the angle change between two iterations is less than a preset angle measurement error threshold or the maximum number of iterations is reached. N max Output the final angle measurement result.

2. The method for progressive angle measurement of burst signals based on iterative feedback according to claim 1, characterized in that: Includes the following steps: S1. The beam pointing calibration of the dual-beam phased array antenna (1) is performed in an anechoic environment to obtain the elevation angle power difference calibration curve and the azimuth angle power difference calibration curve, which are the two-dimensional elevation angle / azimuth angle calibration data. S2. Based on a preset threshold, detect whether there is a sudden signal. The dual-beam phased array antenna (1) measures and compares the cumulative power values ​​of different wave positions in the spatial domain according to a preset path, and obtains the angle information of the wave position with the largest cumulative power value as the initial estimated angle. ; S3. Angle measurement initialization: Set the angle measurement error threshold. Maximum number of iterations Convergence factor The number of iterations i Initialize to 1; S4, the i Secondary elevation plane angle measurement: fix the azimuth angle of both beams of the dual-beam phased array antenna (1). Fixed directions in the pitch direction , Beamcoding is performed to obtain the elevation power difference between the first and second beams. The pitch angle correction amount is obtained by querying the pitch angle power difference calibration curve. ,in, The elevation angle of the dual-beam phased array antenna (1) when the signal attenuation is 3dB; No. i Secondary azimuth plane angle measurement: fix the elevation angle of both beams of the dual-beam phased array antenna (1). The directions are fixed upwards. , Beamcoding is performed to obtain the azimuth power difference between the first and second beams. The azimuth correction amount is obtained by querying the azimuth power difference calibration curve. ,in, The azimuth angle of the dual-beam phased array antenna (1) when the signal attenuation is 3dB; Update angle estimation values: ； S5. Obtain the angle change after two iterations: ； Perform convergence judgment: if ,but i = i +1, to determine the iteration count. If yes, return to step S4 to continue iterating; otherwise, terminate the iteration and output the current best estimate. ; if If the iteration converges, the final angle measurement result will be output. .

3. The burst signal progressive angle measurement method based on iterative feedback according to claim 2, characterized in that: In step S1, the dual-beam phased array antenna (1) is fixed on a two-dimensional turntable in the anechoic chamber. The two-dimensional turntable is adjusted so that the normal of the antenna array surface of the dual-beam phased array antenna (1) is aligned with the direction of the standard horn signal source. The elevation angle power difference calibration curve and the azimuth angle power difference calibration curve are measured. The measurement method for the elevation angle power difference calibration curve is as follows: The angle between the two beams pointing in the elevation direction is set to one half-power beamwidth. The standard horn signal source transmits a continuous wave signal at a fixed frequency and power. The two-dimensional turntable scans within the coverage area in the elevation direction with fixed steps. At each scanning angle position, the received power values ​​of the two beam channels are simultaneously recorded and subtracted to obtain the elevation angle received power difference ΔP_E. The two-dimensional turntable angle corresponding to the zero elevation angle received power difference in the elevation calibration data is the elevation iso-signal axis direction. The absolute angle of the two-dimensional turntable at each calibration point is subtracted from the elevation iso-signal axis angle to obtain the angular deviation Δθ relative to the elevation iso-signal axis. The elevation angle power difference calibration curve is obtained by plotting Δθ as the abscissa and the elevation angle received power difference ΔP_E as the ordinate. The measurement method of the azimuth power difference calibration curve is as follows: The angle between the two beams pointing in the azimuth direction is set to one half-power beamwidth. The standard horn signal source transmits a continuous wave signal at a fixed frequency and power. The two-dimensional turntable scans within the coverage area in the azimuth direction with the fixed step size. At each scanning angle position, the received power values ​​of the two beam channels are recorded simultaneously and the difference is calculated to obtain the azimuth received power difference ΔP_A. The angle of the two-dimensional turntable corresponding to the zero azimuth received power difference in the azimuth calibration data is the azimuth iso-signal axis direction. The absolute angle of the two-dimensional turntable at each calibration point is subtracted from the azimuth iso-signal axis angle to obtain the angle deviation Δφ relative to the azimuth iso-signal axis. The azimuth power difference calibration curve is obtained by plotting Δφ as the abscissa and ΔP_A as the ordinate. The fixed step is 1 / 50 to 1 / 100 of the beamwidth.

4. The burst signal progressive angle measurement method based on iterative feedback according to claim 2, characterized in that: In step S2, the beam scanning range of the dual-beam phased array antenna (1) is ±θ, according to... The circular beam is discretized within the ±θ range to obtain the scanning wave position; During the initial search angle estimation process, the scanning range of the dual-beam phased array antenna (1) and the 3dB beamwidth are discretized into multiple regularly arranged wave points according to the beamwidth. Each wave point corresponds to an angle in the spatial position. The dual-beam phased array antenna (1) is controlled to point to each wave point in sequence and the signal power value of each wave point is measured. The power values ​​of each wave point are compared, and the angle information of the wave point with the largest cumulative power value is used as the initial estimated angle.

5. The burst signal progressive angle measurement method based on iterative feedback according to claim 4, characterized in that: In step S2, the beam scanning range of the dual-beam phased array antenna (1) is ±60°. , The scan wave position is 60 rows.

6. The burst signal progressive angle measurement method based on iterative feedback according to claim 2, characterized in that: In step S3, It is 10. k It is a constant.

7. The burst signal progressive angle measurement method based on iterative feedback according to claim 2, characterized in that: In step S3, The setting range is .

8. The burst signal progressive angle measurement method based on iterative feedback according to claim 2, characterized in that: In step S4, during pitch angle measurement, the pointing angle of the first beam is... The pointing angle of the second beam is ; When measuring the azimuth angle, the pointing angle of the first beam is: The pointing angle of the second beam is .

9. The burst signal progressive angle measurement method based on iterative feedback according to claim 8, characterized in that: In step S4, ; ; in, For the first beam i The cumulative value of the pitch plane angle measurement power in each iteration. For the second beam i The cumulative value of the pitch plane angle measurement power in each iteration. For the first beam i The cumulative value of the azimuth surface angular power in each iteration. For the second beam i The cumulative value of the azimuth surface angular power in each iteration.

10. A burst signal progressive angle measurement method based on iterative feedback according to any one of claims 1 to 9, characterized in that: The dual-beam angle measurement system used in the burst signal progressive angle measurement method includes: a dual-beam phased array antenna (1) and a signal receiving and processing device (2). The dual-beam phased array antenna (1) includes a beam control unit (11), N active phased arrays (12), a passive synthesizing network (13) connected to each of the active phased arrays (12), and a power supply unit (14) for power supply. The signal receiving and processing device (2) includes a system control module (21), a frequency conversion channel (22) connected to the system control module (21), an acquisition and processing unit (23), and a power supply unit (24) for powering the signal receiving and processing device. The frequency conversion channel (22) performs signal amplification, filtering, and downconversion, and the acquisition and processing unit (23) performs signal acquisition, signal detection, and angle measurement processing. The passive synthesis network (14) outputs a first beam and a second beam to the frequency conversion channel (22), wherein the first beam and the second beam are two independently controlled beams.

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