Dynamic environment adaptive waterson-watson direction finding system and method

Abstract

The application provides a dynamic environment self-adapting Watson-Watt direction finding system and method, which comprises a direction finding core module, a combined navigation module and a dynamic compensation module. The combined navigation module collects position, attitude angle, speed and vibration acceleration data of a carrier in real time; the dynamic compensation module corrects frequency offset through a Doppler compensation unit based on the above data, eliminates the influence of attitude change on a direction finding geometric model through a geometric relationship correction unit, and enables adaptive filtering to suppress noise in strong vibration through a dynamic noise suppression unit. The application realizes high-precision and high-real-time direction finding of radio signals on a mobile platform, and significantly improves the anti-interference ability and adaptability of the system in a dynamic environment.

Description

Technical Field

[0001] This invention relates to the intersection of radio direction finding and motion platform navigation technology, specifically a dynamic environment adaptive Watson-Watt direction finding system and method. Background Technology

[0002] The Watson-Watt direction finding technique is a classic and widely used amplitude-based direction finding method. Its basic principle is to determine the direction of arrival by measuring the amplitude ratio of the signal across multiple orthogonal antenna pairs. Traditional Watson-Watt system designs are typically based on a core assumption: the direction-finding antenna array and the radiation source being measured are relatively stationary. However, in real-world mobile applications (such as emergency search and rescue, spectrum monitoring, etc.), the movement of the platform (vehicles, ships, drones) severely disrupts this assumption, leading to a significant degrade in the performance of traditional direction-finding algorithms. This is specifically reflected in the following aspects:

[0003] 1. Doppler Shift: When there is relative radial motion between the direction-finding platform and the radiation source, the carrier frequency of the received signal will shift, i.e., Doppler shift. Its magnitude can be expressed as Δf = (2v / λ) · cosθ, where v is the velocity of the platform (relative velocity), λ is the signal wavelength, and θ is the signal direction component. This shift causes the center frequency of the received signal to deviate from the receiver's preset optimal operating point, resulting in signal amplitude measurement distortion and thus introducing significant direction-finding errors. This problem is particularly prominent on high-speed moving platforms.

[0004] 2. Attitude Change Interference: During movement, mobile platforms inevitably experience attitude changes such as roll, pitch, and yaw. These attitude angle changes directly alter the relative positions and orientations of the antenna array elements in space, disrupting the fixed, horizontal array geometry model upon which traditional direction-finding algorithms rely. For example, if a horizontal Adcock antenna array tilts, the reference plane for calculating the signal incident angle changes accordingly. Without correction, this will directly lead to errors in the calculation of azimuth and pitch angles.

[0005] 3. Enhanced Dynamic Noise: Mechanical vibrations of the moving platform and engine operation introduce additional broadband vibration noise. This environmental noise couples into the RF receiving channel, particularly reducing the system's detection sensitivity and direction-finding signal-to-noise ratio for weak signals (such as emergency beacon signals and UAV remote control signals). During periods of strong vibration, traditional direction-finding systems may completely fail.

[0006] Currently, existing technical solutions mostly focus on improving direction-finding accuracy in static or quasi-static environments, such as by optimizing antenna array layout and improving signal processing algorithms. However, they generally lack systematic and real-time compensation mechanisms for the aforementioned dynamic factors. The few solutions that involve dynamic compensation often only address a single factor (such as compensating only for Doppler frequency shift or performing only coarse attitude stabilization), failing to form an integrated and adaptive solution, and their real-time performance is insufficient to meet the continuous tracking requirements of highly dynamic platforms. Summary of the Invention

[0007] This invention provides a dynamic environment adaptive Watson-Watt direction finding system and method. It proposes a direction finding system architecture of "multi-sensor fusion dynamic compensation + real-time calibration". By integrating combined navigation module sensors, it can acquire the precise motion state (velocity, position) and spatial attitude (roll, pitch, yaw) of the carrier in real time. It uses this information to perform feedforward or feedback compensation and correction on key links (signal frequency, geometric model, noise basis) in the Watson-Watt direction finding process.

[0008] A dynamically adaptive Wattson-Watt direction finding system includes:

[0009] The direction finding core module is used to receive radio signals and output preliminary direction finding results θ';

[0010] The integrated navigation module is used to collect the carrier's attitude angle, velocity v, and vibration acceleration data in real time.

[0011] The dynamic compensation module includes:

[0012] Doppler compensation unit: Calculates the Doppler frequency shift Δf based on the velocity v and preliminary direction finding results θ' collected by the integrated navigation module, and adjusts the numerically controlled oscillator of the receiver's radio frequency front end based on the Doppler frequency shift Δf to correct the local oscillation frequency and compensate for the frequency shift caused by relative motion;

[0013] The geometric relationship correction unit is used to construct a transformation matrix from the carrier coordinate system to the geographic coordinate system based on the carrier attitude angles collected by the integrated navigation module. The transformation matrix is ​​then used to correct the antenna array geometric model, eliminate the influence of attitude changes on the calculation of signal incident angle, and thus correct the preliminary direction finding results.

[0014] Dynamic noise suppression unit: Monitors the vibration acceleration data output by the integrated navigation module. When the vibration intensity exceeds a preset threshold, it activates an adaptive filter to process the received radio signals in order to suppress noise introduced by the carrier vibration.

[0015] Furthermore, the carrier attitude angles include roll angle α, pitch angle β, and heading angle γ.

[0016] Furthermore, the formula for calculating the Doppler frequency shift is: Δf=(2v / λ)·cosθ', where λ is the signal wavelength.

[0017] Furthermore, the step of using the transformation matrix to correct the antenna array geometric model, eliminating the influence of attitude changes on the signal incident angle calculation, and thus correcting the preliminary direction finding results, includes:

[0018] By transforming the coordinates, the preliminary direction finding results calculated by the direction finding core module based on the carrier coordinate system are converted to the geographic coordinate system to obtain the true direction of arrival of the wave, which is not affected by the current attitude of the carrier.

[0019] A dynamically adaptive Wattson-Watt direction finding method includes the following steps:

[0020] Receive radio signals and output preliminary direction finding results θ';

[0021] Real-time acquisition of carrier attitude angle, velocity v, and vibration acceleration data;

[0022] The Doppler frequency shift Δf is calculated based on the acquired velocity v and the preliminary direction finding result θ'. The numerically controlled oscillator of the receiver's radio frequency front end is adjusted based on the Doppler frequency shift Δf to correct the local oscillation frequency and compensate for the frequency shift caused by relative motion.

[0023] Based on the carrier attitude angles collected by the integrated navigation module, a transformation matrix from the carrier coordinate system to the geographic coordinate system is constructed. The antenna array geometric model is then corrected using the transformation matrix to eliminate the influence of attitude changes on the calculation of the signal incident angle, thereby correcting the preliminary direction finding results.

[0024] The system monitors vibration acceleration data. When the vibration intensity exceeds a preset threshold, an adaptive filter is activated to process the received radio signals in order to suppress noise introduced by the carrier vibration.

[0025] Furthermore, the carrier attitude angles include roll angle α, pitch angle β, and heading angle γ.

[0026] Furthermore, the formula for calculating the Doppler frequency shift is: Δf=(2v / λ)·cosθ', where λ is the signal wavelength.

[0027] Furthermore, the step of using the transformation matrix to correct the antenna array geometric model, eliminating the influence of attitude changes on the signal incident angle calculation, and thus correcting the preliminary direction finding results, includes:

[0028] By transforming the coordinates, the preliminary direction finding results calculated by the core direction finding module based on the carrier coordinate system are converted to the geographic coordinate system to obtain the true direction of arrival of the wave, which is not affected by the current attitude of the carrier.

[0029] The present invention has the following beneficial effects:

[0030] 1. Excellent resistance to motion interference:

[0031] By deeply integrating information from multiple sources such as inertial and satellite data, the system systematically compensates for the two core dynamic error sources: Doppler frequency shift and carrier attitude change. This enables the direction finding system to maintain near-static direction finding accuracy even on high-speed mobile platforms such as ships, with an accuracy improvement of over 60% in actual dynamic environments.

[0032] 2. Excellent real-time performance:

[0033] The key compensation algorithm is implemented on an FPGA hardware platform, with low processing latency (≤50ms) and high direction finding update rate (≥10Hz), which can meet the requirements for continuous and stable tracking of high-speed moving radiation sources or rapid maneuvering of the platform itself.

[0034] 3. High system robustness:

[0035] An adaptive noise suppression mechanism based on vibration sensing is introduced, which can dynamically adjust the signal processing strategy according to the severity of the environment, significantly improving the detection and direction finding capabilities of weak signals, especially in harsh physical environments such as vibration and shock, making the system more adaptable.

[0036] 4. High feasibility of engineering implementation:

[0037] The integrated navigation module sensor used is not a mature commercial product, the compensation algorithm has a clear structure, and it is easy to upgrade and modify the existing Wattson-Watt direction finding equipment, which has high value for promotion and application. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the dynamic environment adaptive Wattson-Watt direction finding system of the present invention.

[0039] Figure 2 This is a flowchart of the dynamic environment adaptive Wattson-Watt direction finding method of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Please see Figure 1This invention provides a dynamically adaptive Wattson-Watt direction finding system, characterized in that it includes:

[0042] The direction-finding core module is built based on the classic Watson-Watt direction-finding principle. It includes a multi-channel Adcock antenna array (or other suitable array), a corresponding RF receiving module (containing a low-noise amplifier, mixer, filter, etc.), and a signal processing unit. The direction-finding core module is responsible for receiving radio signals, down-converting them, performing analog-to-digital conversion, executing the initial direction-finding algorithm, and outputting the preliminary direction-finding result θ'.

[0043] Integrated navigation module: used to provide the vehicle's absolute position, velocity v, vehicle attitude angles (roll angle α, pitch angle β, yaw angle γ) and acceleration data.

[0044] The dynamic compensation module includes:

[0045] Compensation processor: Receives data from the integrated navigation module and the preliminary direction finding results from the direction finding core module, and executes the compensation algorithm.

[0046] Real-time calibration module: This module is the functional implementation part of the dynamic compensation module, and specifically includes:

[0047] Doppler compensation unit: Based on the carrier's velocity v (from GPS) and the preliminary direction finding result θ', the Doppler frequency shift Δf = (2v / λ) · cosθ' is calculated, where λ is the signal wavelength. This Doppler frequency shift is sent to the numerically controlled oscillator (NCO) of the signal processing module, where the local oscillator frequency is finely adjusted to cancel the Doppler effect, ensuring that subsequent signal processing is based on the correct center frequency.

[0048] Geometric Relationship Correction Unit: Based on the obtained carrier attitude angles (roll angle α, pitch angle β, and heading angle γ), a transformation matrix is ​​constructed from the carrier coordinate system to the geographic coordinate system. Using this transformation matrix, the spatial position of the antenna array is remapped, correcting the original two-dimensional direction-finding geometric model based on the horizontal plane assumption into a three-dimensional spatial geometric model that can reflect the actual attitude of the carrier, thereby calculating the accurate signal incidence angle.

[0049] Dynamic noise suppression unit: Monitors the vibration acceleration data output by the inertial measurement unit (IMU) (usually calculating its variance as a vibration intensity index). When the vibration intensity exceeds a preset threshold, an adaptive filter (Wiener filter) is automatically activated to process the received radio signals to suppress noise introduced by the carrier vibration.

[0050] Please see Figure 2 This invention also provides a dynamically adaptive Wattson-Watt direction finding method, comprising the following steps:

[0051] Step S1: Receive radio signals and output preliminary direction finding results θ';

[0052] Step S2: Real-time data acquisition and attitude monitoring: The integrated navigation module continuously acquires the vehicle's attitude angles (roll angle α, pitch angle β, heading angle γ) at a high frequency (20Hz); the GPS module integrated into the integrated navigation module provides speed and position updates (1Hz).

[0053] Step S3: Doppler Frequency Shift Prediction and Compensation: While the direction-finding core module is processing the signal, the Doppler compensation unit, combining the vehicle's velocity v provided by GPS and the preliminary direction-finding result θ' (or the precise result from the previous cycle) output by the direction-finding core module, calculates the current frequency shift to be compensated according to the formula Δf = (2v / λ) · cosθ', where λ is the signal wavelength. This frequency shift is sent to the NCO in the RF receiving channel to achieve real-time pre-correction of the received signal frequency.

[0054] Step S4: Dynamic correction of antenna geometry:

[0055] The geometric correction unit receives the carrier's attitude angles (roll angle α, pitch angle β, and heading angle γ) and preliminary azimuth observations based on a tilt array output from the direction-finding core module. Using the attitude angle information, the unit constructs a transformation matrix from the carrier coordinate system to the geographic coordinate system. This matrix transforms the preliminary observations from the carrier coordinate system to the geographic coordinate system, thereby eliminating the influence of carrier attitude changes on the geometric model and directly calculating and outputting the true azimuth relative to geographic north.

[0056] The correction principle and mathematical model are introduced below:

[0057] 1) Definition of coordinate system

[0058] Geographic coordinate system (G system): O-XYZ. The origin O is the phase center of the antenna array.

[0059] X-axis: points to geographic north.

[0060] Y-axis: points to geographical east.

[0061] Z-axis: Points towards the Earth's center (Down)

[0062] In this coordinate system, the direction of a far-field radiation source can be represented by the unit direction vector V_g.

[0063] Carrier coordinate system (B system): O-xyz. Fixed to the carrier.

[0064] x-axis: points forward of the carrier's longitudinal axis (Roll Axis)

[0065] y-axis: points to the starboard side of the vehicle (Pitch Axis)

[0066] z-axis: points downwards from the carrier (Yaw Axis)

[0067] The geometric layout of the antenna array and the preliminary calculation results of the direction-finding core module are both based on this coordinate system.

[0068] 2.) Coordinate transformation matrix (from the system of reference to the geographic system)

[0069] By performing three basic Euler rotations, a transformation matrix C_b^g can be constructed from the vehicle coordinate system (B) to the geographic coordinate system (G). The rotation order is typically: yaw (γ) -> pitch (β) -> roll (α). The final transformation matrix C_b^g is the product of these three rotation matrices:

[0070] C_b^g = R_z(γ) * R_y(β) * R_x(α)

[0071] Where R_x(α), R_y(β), and R_z(γ) are rotation matrices about the x, y, and z axes, respectively.

[0072] 3) Transformation of direction vectors

[0073] Let V_b be the unit direction vector of a far-field radiation source in the carrier coordinate system (B frame). This vector is the direction vector directly measured or preliminarily calculated by the Watson-Watt direction finding core module based on the induced voltage relationship of the tilted array.

[0074] The true direction vector V_g of this vector in the geographic coordinate system (G system) can be obtained by the following formula: V_g = C_b^g · V_b

[0075] The correction method is executed in real time in the system's "geometric relationship correction unit" according to the following steps:

[0076] Step S3.1: Obtain input data

[0077] The carrier attitude angles, namely roll angle α, pitch angle β, and yaw angle γ, are obtained in real time from the integrated navigation module.

[0078] The initial orientation finding result in the vehicle coordinate system is obtained from the orientation finding core module. This initial orientation finding result can be the initial azimuth angle θ_b calculated directly based on the tilted array model.

[0079] Step S3.2: Construct the direction vector

[0080] Based on the initial azimuth angle θ_b, a unit direction vector V_b is constructed in the (ideal) horizontal carrier coordinate system.

[0081] V_b = [ sin(θ_b), cos(θ_b), 0 ]^T

[0082] Step S3.3: Calculate the coordinate transformation matrix

[0083] Calculate the transformation matrix C_b^g from the vehicle coordinate system (B) to the geographic coordinate system (G) based on the attitude angles (α, β, γ).

[0084] C_b^g = R_z(γ) • R_y(β) • R_x(α)

[0085] Where R_x, R_y, and R_z are the basic rotation matrices about each axis.

[0086] Step S3.4: Perform coordinate transformation and extract the horizontal component.

[0087] Calculate the direction vector in the geographic coordinate system:

[0088] V_g = C_b^g • V_b

[0089] Get V_g = [X_g, Y_g, Z_g]^T.

[0090] The information needed to calculate the azimuth is X_g (north component) and Y_g (east component).

[0091] Step S3.5: Calculate and output the true azimuth angle

[0092] Calculate the true azimuth angle Az of the incoming wave using X_g and Y_g (with geographic north as the reference):

[0093] Az = atan2(X_g, Y_g)

[0094] atan2 is the four-quadrant arctangent function. It determines the correct quadrant of the angle based on the signs of X_g and Y_g, and provides a unique solution within the range of (0°, 360°).

[0095] The calculated result Az is the corrected, final output true azimuth angle.

[0096] Step S4: Dynamic Noise Sensing and Suppression: The dynamic noise suppression unit continuously calculates the variance of the vibration acceleration data of the integrated navigation module. When it is determined that the carrier is in a strong vibration state (variance exceeds the threshold of 0.1g²), the filter parameters in the signal processing path are automatically switched or adjusted, and an adaptive filtering algorithm is enabled. This sacrifices some response speed in exchange for higher noise suppression capability, ensuring that signal features can still be effectively extracted even in harsh vibration environments.

[0097] To ensure the effectiveness of the compensation, especially for rapidly changing motion states, this invention deploys the aforementioned compensation algorithms (particularly attitude calculation, geometric correction, and Doppler calculation) on a high-speed hardware platform, executing them in a Field-Programmable Gate Array (FPGA). Through hardware parallel processing capabilities and pipelined design, the overall processing latency from sensor data input to compensation output is ensured to be no greater than 50 milliseconds. This enables the system to support direction finding update rates exceeding 10Hz, fully meeting the real-time tracking requirements of most motion platforms for dynamic targets.

[0098] Implementation Case: Shipborne High-Precision Radio Direction Finding System

[0099] Work Scenario: A certain type of ship needs to perform direction finding on an unknown radio signal with a frequency range of 100MHz to 512MHz. The ship is traveling at a speed of approximately 20 knots (approximately 10 meters per second, or 36 kilometers per hour), and the sea conditions are causing the hull to experience continuous rolling and vibration.

[0100] System Configuration:

[0101] The direction-finding antenna uses a four-element Adcock array.

[0102] The integrated navigation module uses the INS-V2.0 module.

[0103] The compensation algorithm runs within the XC7Z100 FPGA chip.

[0104] Compensation process:

[0105] 1. Attitude monitoring:

[0106] The integrated navigation module monitored the dynamic changes of the ship's roll angle α=3°, pitch angle β ≈ 5°, and yaw angle γ ≈10° in real time. The ship's speed V=10m / s and acceleration=0.15g.

[0107] 2. Doppler compensation:

[0108] The initial direction finding result is a signal with θ' = 50° and a frequency of 400MHz (λ = 0.75m). The Doppler compensation unit calculates Δf ≈ 2 * 10 / 0.75 * cos(50°) ≈ 17.16 Hz. This value is sent to the NCO of the RF front end, causing its output frequency to be adjusted accordingly by Δf to compensate for the Doppler frequency shift.

[0109] 3. Geometric relationship correction:

[0110] Upon receiving (α, β, γ), the geometric correction unit calculates in real time the changes in the array normal caused by a 3° roll angle, a 5° pitch angle, and a 10° yaw angle. It then corrects the theoretical horizontal incident angle model to an actual three-dimensional incident angle model under the current ship attitude through coordinate transformation.

[0111] Calculation process:

[0112] Step S3.1: Obtain input data

[0113] Preliminary azimuth θ_b = 50°

[0114] Attitude angles (α, β, γ) = (3°, 5°, 10°)

[0115] Step S3.2: Construct the carrier orientation vector

[0116] The θ_b output by the direction-finding core is the angle calculated starting from the front (x-axis) of the vehicle. A unit direction vector V_b is constructed in the (ideal) horizontal vehicle coordinate system: V_b = [ sin(θ_b), cos(θ_b), 0 ]^T = [ sin(50°), cos(50°), 0 ]^T ≈ [0.7660, 0.6428, 0.0000]^T

[0117] Step S3.3: Calculate the coordinate transformation matrix C_b^g

[0118] The transformation matrix C_b^g = R_z(γ) • R_y(β) • R_x(α) is given by: where the fundamental rotation matrix is:

[0119] ;

[0120] ;

[0121] ;

[0122] The calculation yielded:

[0123] ;

[0124] Step S3.4: Perform coordinate transformation

[0125] Calculate the direction vector V_g in the geographic coordinate system:

[0126] V_g = C_b^g • V_b≈ [0.9030, 0.4294, 0.0450]^T

[0127] get:

[0128] The northward component X_g ≈ 0.9030

[0129] The eastward component Y_g ≈ 0.4294

[0130] The celestial component Z_g ≈ 0.0450

[0131] Step S3.5: Calculate and output the true azimuth angle

[0132] Calculate the true azimuth angle Az of the incoming wave using X_g and Y_g:

[0133]

[0134] 4. Dynamic noise suppression:

[0135] The system detected better performance than engine and wave impact, with an acceleration variance of 0.15g. 2 It exceeds the preset 0.1g. 2 Threshold. The dynamic noise suppression unit enables the Wiener filter to adaptively filter the intermediate frequency signal received by the quad-element antenna, effectively suppressing background noise caused by vibration.

[0136] The dynamic noise suppression module activates Wiener filtering based on vibration acceleration (variance > 0.1g²) to filter out high-frequency vibration noise;

[0137] Actual test results:

[0138] In a one-hour experiment, compared with the case without compensation system, the azimuth direction finding error of the shore-based beacons at multiple known locations was significantly reduced and stabilized within ±3° after the compensation system was enabled, which was ±8° when it was not compensated. This fully demonstrates the effectiveness and superiority of the present invention in real dynamic environments.

[0139] This system is particularly suitable for high-precision, real-time radio direction of arrival estimation on highly mobile platforms in complex electromagnetic environments.

[0140] This invention has the following features and advantages:

[0141] 1. Significantly improves direction finding accuracy and anti-interference capability in dynamic environments: By integrating a combined navigation module to acquire carrier speed, attitude and vibration data in real time, and using a dynamic compensation module to simultaneously implement Doppler frequency shift compensation, geometric relationship correction and adaptive noise suppression, the influence of carrier motion on direction finding results is systematically eliminated, so that the system can maintain near-static direction finding performance on highly dynamic platforms (such as ships and vehicles), with actual measurement accuracy improved by more than 60%.

[0142] 2. Achieve high real-time performance and continuous tracking capability: The key compensation algorithm is implemented based on the FPGA hardware platform, with low processing latency (≤50ms) and high direction finding update rate (≥10Hz), which can meet the continuous and stable tracking requirements of high-speed mobile platforms for radiation sources.

[0143] 3. Enhanced system environmental adaptability and robustness: By dynamically enabling adaptive filtering through vibration sensing mechanism, noise introduced by carrier vibration is effectively suppressed, improving the ability to detect and locate weak signals in harsh physical environments, and making the overall system more adaptable.

[0144] 4. Easy to implement and promote in engineering: The system has a clear architecture, uses mature commercial products for its combined navigation modules, and has a modular design for its compensation algorithm, which makes it easy to upgrade and modify existing Wattson-Watt direction finding equipment. It has high practical value and promising prospects for promotion and application.

[0145] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A dynamically adaptive Watson-Watt direction finding system, characterized in that, include: The direction finding core module is used to receive radio signals and output preliminary direction finding results θ'; The integrated navigation module is used to collect the carrier's attitude angle, velocity v, and vibration acceleration data in real time. The dynamic compensation module includes: Doppler compensation unit: Calculates the Doppler frequency shift Δf based on the velocity v and preliminary direction finding results θ' collected by the integrated navigation module, and adjusts the numerically controlled oscillator of the receiver's radio frequency front end based on the Doppler frequency shift Δf to correct the local oscillation frequency and compensate for the frequency shift caused by relative motion; The geometric relationship correction unit is used to construct a transformation matrix from the carrier coordinate system to the geographic coordinate system based on the carrier attitude angles collected by the integrated navigation module, and use the transformation matrix to correct the antenna array geometric model, eliminate the influence of attitude changes on the calculation of signal incident angle, and thus correct the preliminary direction finding results. Dynamic noise suppression unit: Monitors the vibration acceleration data output by the integrated navigation module. When the vibration intensity exceeds a preset threshold, it activates an adaptive filter to process the received radio signals in order to suppress noise introduced by the carrier vibration.

2. The system according to claim 1, characterized in that, The carrier attitude angles include roll angle α, pitch angle β, and heading angle γ.

3. The system according to claim 1, characterized in that, The formula for calculating the Doppler frequency shift is: Δf=(2v / λ)·cosθ', where λ is the signal wavelength.

4. The system according to claim 1, characterized in that, The step of using the transformation matrix to correct the antenna array geometric model, eliminating the influence of attitude changes on the calculation of the signal incident angle, and thus correcting the preliminary direction finding results includes: By transforming the coordinates, the preliminary direction finding results calculated by the direction finding core module based on the carrier coordinate system are converted to the geographic coordinate system to obtain the true direction of arrival of the wave, which is not affected by the current attitude of the carrier.

5. A dynamically adaptive Watson-Watt direction finding method, characterized in that, Includes the following steps: Receive radio signals and output preliminary direction finding results θ'; Real-time acquisition of carrier attitude angle, velocity v, and vibration acceleration data; The Doppler frequency shift Δf is calculated based on the acquired velocity v and the preliminary direction finding result θ'. The numerically controlled oscillator of the receiver's radio frequency front end is adjusted based on the Doppler frequency shift Δf to correct the local oscillation frequency and compensate for the frequency shift caused by relative motion. Based on the carrier attitude angles collected by the integrated navigation module, a transformation matrix from the carrier coordinate system to the geographic coordinate system is constructed. The antenna array geometric model is then corrected using the transformation matrix to eliminate the influence of attitude changes on the calculation of the signal incident angle, thereby correcting the preliminary direction finding results. The system monitors vibration acceleration data. When the vibration intensity exceeds a preset threshold, an adaptive filter is activated to process the received radio signals in order to suppress noise introduced by the carrier vibration.

6. The method according to claim 5, characterized in that, The carrier attitude angles include roll angle α, pitch angle β, and heading angle γ.

7. The method according to claim 5, characterized in that, The formula for calculating the Doppler frequency shift is: Δf=(2v / λ)·cosθ', where λ is the signal wavelength.

8. The method according to claim 5, characterized in that, The step of using the transformation matrix to correct the antenna array geometric model, eliminating the influence of attitude changes on the calculation of the signal incident angle, and thus correcting the preliminary direction finding results includes: By transforming the coordinates, the preliminary direction finding results calculated by the core direction finding module based on the carrier coordinate system are converted to the geographic coordinate system to obtain the true direction of arrival of the wave, which is not affected by the current attitude of the carrier.

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