A method and system for time delay and phase compensation beamforming

Abstract

The present application relates to the field of beam forming, in particular to a method and system for delay and phase compensation of beam forming. The method comprises: calculating a theoretical delay value to be applied to each array element signal according to the position coordinates of each array element in the array and the beam forming direction; quantizing the theoretical delay value to calculate the address offset of each array element; calculating a delay compensation value using the address offset, and calculating the difference between the delay compensation value and the theoretical delay value as the phase compensation value of the array element received signal; sampling and pre-processing the signal received by each array element to obtain a complex signal, and sequentially performing addressing operation and phase shift operation on the complex signal according to the calculated address offset and phase compensation value; performing weighting processing on the signal after the phase shift operation, and accumulating, and finally outputting the beam forming data. The present application realizes rough compensation by delay processing at a low sampling rate, realizes accurate compensation by phase shift processing, and finally realizes in-phase superposition of signals.

Description

Technical Field

[0001] This invention relates to the field of beamforming, and in particular to a beamforming method and system with delay phase compensation. Background Technology

[0002] Beamforming is a common technique in array signal processing, widely used in radar, communication, and sonar signal processing. It amplifies signals from a specific direction while suppressing echoes from other directions, improving the signal-to-noise ratio (SNR) for that direction. It enhances the SNR through the coherent superposition of signals from multiple array elements. The basic idea of ​​beamforming is to delay or phase-shift the signals received by each array element to achieve in-phase, coherent superposition of these signals. Since the noise between array elements is uncorrelated, beamforming's effect on noise is incoherent superposition. Therefore, the theoretical SNR gain of beamforming is given by , where is the number of array elements involved in the beamforming calculation.

[0003] Beamforming methods are broadly classified into two categories: delay beamforming and phase-shift beamforming. Delay beamforming superimposes the delayed signals received by each array element. It does not produce aperture filling effects, but achieving comparable accuracy with phase-shift beamforming requires a high sampling rate and computational load. It is generally considered that to achieve 1° angular resolution, the sampling rate needs to be at least 30 times the carrier frequency. This necessitates interpolation and filtering of the data after the bandpass sampling signal, resulting in high computational load and data throughput.

[0004] Phase-shift beamforming utilizes the phase shift of signals received by array elements at the same time and then superimposes them. It features high accuracy and low computational complexity. However, when phase-shift beamforming is applied to large-aperture arrays, it can cause aperture filling effect. That is, when the beamforming angle is large, the array elements at both ends cannot receive signals simultaneously or a small portion of the signals overlap in time, resulting in energy loss, pulse broadening, and affecting beamforming gain.

[0005] Assuming the direction of incoming wave is basically the same as the beamforming direction, the signals received by each array element are as follows: Figure 1 As shown, the phase beamforming method phase-shifts the signals received by each array element, resulting in all elements contributing and the signals being completely superimposed, limited to the central region of the pulse. Figure 1 The area within the solid-lined box. At this point, the beamformed signal will exhibit pulse broadening. If the beamforming angle continues to deflect, the moment when all array element signals are completely superimposed will not occur, and the beamforming gain will significantly decrease. Although time-delay beamforming can achieve full array accumulation over the entire pulse time range by offset addressing the data, it incurs tens of times the computational complexity and throughput compared to phase beamforming. The aperture fill factor R is defined as:

[0006]

[0007] Where D is the maximum aperture length of the array, and τ0 is the pulse width.

[0008] The greater the aperture filling factor, the greater the influence on the phase beamforming. SUMMARY

[0009] The present application aims to overcome the shortcomings of large computation of delay beamforming and large influence of aperture filling effect of phase beamforming, and proposes a delay and phase compensation beamforming method, which is suitable for various planar arrays and linear arrays. The method realizes rough compensation through delay processing at low sampling rate, realizes accurate compensation through phase shift processing, and finally realizes in-phase superposition of signals. The delay processing of low sampling signals avoids the aperture filling effect and reduces the computation complexity caused by high sampling rate. The phase difference between the rough compensation delay and the theoretical delay between each array element is compensated further by the phase shift processing, and finally the phase is accurately compensated. Simulation results show that the delay and phase compensation beamforming method proposed by the present application can realize beamforming gain close to the theory, and has good performance in the case of large beam deflection angle and large aperture filling factor, and the computation complexity is much lower than that of the conventional beamforming algorithm.

[0010] To achieve the above object, the present application realizes the technical scheme as follows.

[0011] The present application proposes a delay and phase compensation beamforming method, which comprises the following steps:

[0012] Step 1. Calculate the theoretical delay value to be applied to each array element signal by using the position coordinates of each array element in the array and the beamforming direction;

[0013] Step 2. Quantize the theoretical delay value to calculate the address offset of each array element, calculate the delay compensation value by using the address offset, and calculate the difference between the delay compensation value and the theoretical delay value as the phase compensation value of the array element received signal;

[0014] Step 3. Sample and preprocess the signals received by each array element to obtain complex signals, and sequentially perform addressing operation and phase shift operation on the complex signals according to the calculated address offset and phase compensation value;

[0015] Step 4. Perform weighting processing on the signals after phase shift operation, and accumulate to finally output the beamforming data.

[0016] As one of the improvements of the above technical scheme, the step 1 specifically comprises:

[0017] Step 1-1. Calculate the position coordinates of each array element in the local coordinate system by using the position coordinates of each array element in the carrier coordinate system.

[0018] Step 1-2. Calculate the angle between the position coordinate vector of each array element in the carrier coordinate system and the corresponding beamforming pointing angle unit vector;

[0019] Steps 1-3. Calculate the theoretical delay of each array element at the l-th pointing angle using the obtained included angle.

[0020] As an improvement to the above technical solution, in step 1-1, for an M*N array, the position coordinates of the array element in the m-th row and n-th column in the local coordinate system are... The formula for calculation is:

[0021]

[0022] Wherein, Γ(t) represents the value of the bow rocking. Rotation matrices in the three directions of pitch P(t) and roll R(t) Γ P (t), Γ R (t) is the rotation matrix synthesized. This represents the position coordinates of the array element in the m-th row and n-th column in the carrier coordinate system; m = 1, 2, 3, ..., M; n = 1, 2, 3, ..., N;

[0023] In steps 1-2, the position coordinate vector A′ of the array element in the m-th row and n-th column in the local coordinate system. m，n =[x′ m，n y′ m，n z′ m，n ] T The subscript T represents the transpose of the vector.

[0024] In steps 1-2, the position coordinate vector A′ of the array element in the m-th row and n-th column in the local coordinate system. m，n The beam forms a unit vector B pointing angle. l The included angle θ m，n，l The formula for calculation is:

[0025]

[0026] Where; l is the beamforming pointing angle index; |·| operation is vector modulus calculation; B l The pitch angle is α l The azimuth angle is β l The beamforming pointing angle unit vector is expressed as:

[0027] B l =[cosα l cosβ l cosα l sinβl sinα l ] T

[0028] In steps 1-3, the theoretical delay τ of the array element in the m-th row and n-th column at the l-th pointing angle is... m，n，l The formula for calculation is:

[0029]

[0030] Where c is the speed of sound.

[0031] As one of the improvements to the above technical solution, the bow rocking Rotation matrices in the three directions of pitch P(t) and roll R(t) Γ P (t), Γ R The formulas for calculating (t) are as follows:

[0032]

[0033]

[0034]

[0035] The formula for calculating the rotation matrix Γ(t) is:

[0036] As an improvement to the above technical solution, step 2 involves quantizing the theoretical delay value to calculate the address offset of each array element, specifically including:

[0037] The theoretical delay values ​​of each array element are rounded according to the signal sampling rate to obtain the address offset of each array element. Among them, the address offset D of the array element in the m-th row and n-th column is... m，n，l The formula for calculation is:

[0038]

[0039] in, For the floor operation, f s The signal sampling rate;

[0040] The phase compensation value p′ of the array element received in the m-th row and n-th column m，n，l The formula for calculation is:

[0041] p′ m，n，l =2πf s (τ m，n，l -D m，n，l / f s ).

[0042] As one of the improvements of the above technical solutions, in the step 3, the complex signal is obtained by sampling and preprocessing the signal received by each array element, wherein the sampling is completed by an analog-to-digital converter, and the preprocessing includes digital band-pass filtering or demodulation.

[0043] As one of the improvements of the above technical solutions, the complex signal S m，n (i) is obtained by performing the phase shift operation on the signal S m，n，l (i) is expressed as:

[0044] S′ m，n，l (i) = S m，n (i-D m，n，l )

[0045] Wherein, i is the serial number of the sampling point.

[0046] The signal S″ m，n，l (f) is obtained by performing the phase shift operation on the signal S m，n，l (f) is expressed as:

[0047]

[0048] Wherein, is the Hilbert transform of S m，n (i), and H represents the conjugate transpose.

[0049] As one of the improvements of the above technical solutions, in the step 4, the beam forming signal is finally output, wherein the signal U l (t) output after the beam forming of the lth is:

[0050]

[0051] That is, the signal gain after the beam forming is M*N times.

[0052] The application further provides a delay and phase compensation beam forming system, the system comprises an array and a signal processing module, wherein,

[0053] The array comprises a plurality of array elements, and each array element is used for receiving a signal.

[0054] The signal processing module is configured to calculate a theoretical delay value to be applied to each array element signal according to the position coordinates of each array element in the array and the beam forming direction; to quantize the theoretical delay value to calculate the address offset of each array element, calculate the delay compensation value using the address offset, and calculate the difference between the delay compensation value and the theoretical delay value as the phase compensation value of the array element received signal; to sample and pre-process the signals received by each array element to obtain complex signals, and sequentially perform addressing operation and phase shift operation on the complex signals according to the calculated address offset and phase compensation value; and to further perform weighting processing on the signals after the phase shift operation and accumulate the signals to finally output the beam forming data.

[0055] Compared with the prior art, the present application has the following advantages:

[0056] 1. The delay processing of the low sampling signal in the method avoids the aperture filling effect and reduces the calculation complexity caused by high sampling rate, and roughly compensates the phase difference between the delay and the theoretical delay between each array element.

[0057] 2. The phase shift processing of the method further compensates the residual phase difference, and finally realizes accurate compensation of the phase.

[0058] 3. The delay and phase compensation beam forming method proposed in the present application can realize beam forming gain close to the theory, and has good performance in the case of large beam deflection angle and large aperture filling coefficient, and the calculation complexity is much lower than that of the conventional beam forming algorithm. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 is an aperture filling effect and beam forming schematic diagram;

[0060] Figure 2 is a processing flow of the delay and phase compensation method of beam forming;

[0061] Figure 3 is a time domain graph of the beam forming results of three methods when R=0.64;

[0062] Figure 4 is a time domain graph of the beam forming results of three methods when R=2.56;

[0063] Figure 5 is the influence of the aperture filling coefficient on the beam forming gain;

[0064] Figure 6 is the influence of the beam forming pointing angle on the gain. DETAILED DESCRIPTION

[0065] The technical solutions of the present application will be described in detail below with reference to the drawings and examples.

[0066] Embodiment 1

[0067] I. Method Introduction

[0068] In multi-beam sounding sonar and positioning sonar, it is usually necessary to use attitude stabilization technology. Regardless of the attitude of the carrier (the carrier refers to the carrier of the sonar, such as a ship, an airship, an underwater vehicle, etc.), the attitude stabilization technology can keep the beam pointing direction unchanged relative to the earth, ensuring that the carrier can also enhance the signal in the specified direction in the state of rocking, ensuring the signal-to-noise ratio and angle measurement accuracy. A three-dimensional coordinate system of the carrier is established, with the port direction as the positive direction of the y-axis, the head direction of the carrier as the positive direction of the x-axis, and the sky direction as the positive direction of the z-axis. For t time, the roll angle R(t) is positive when the port is raised, the pitch angle P(t) is positive when the head of the carrier is raised, and the yaw angle Y(t) is positive when the starboard is deflected to the right.

[0069] The processing flow of the delay and phase compensation method of beam forming is as shown in Figure 2

[0070] The processing steps of the delay and phase compensation method of beam forming are as follows:

[0071] Step 1: According to the three-direction attitude data collected by the attitude sensor, the real-time positions of each array element in the local coordinate system are calculated.

[0072] Step 2: Using the real-time positions of each array element and the beam forming direction, the theoretical delay value to be applied to each array element signal is calculated.

[0073] Step 3: The theoretical delay value is quantized to calculate the address offset of each array element.

[0074] Step 4: The difference between the delay compensation value and the theoretical delay value is calculated as the phase compensation value.

[0075] Step 5: The digital signal output by the AD sampling is filtered and demodulated, etc., to transform the signal into a narrowband complex signal.

[0076] Step 6: According to the address offset calculated in step 3, the complex signal is addressed.

[0077] Step 7: According to the phase compensation value calculated in step 4, the signal is phase-shifted.

[0078] Step 8: The weighted processing of the phase-shifted signal is performed, and after accumulation, the beam forming data is finally output.

[0079] II. Specific Implementation Description

[0080] The specific processing method of each processing module is described as follows: ​​

[0081] 1. Attitude acquisition and stabilization

[0082] For a planar array of M*N, where m=1,2,3,…,M, n=1,2,3,…,N. When the carrier has attitude changes, the rotation matrix is calculated as follows:

[0083]

[0084]

[0085]

[0086]

[0087] Γ P (t), Γ R (t) are the rotation matrices of yaw P(t), pitch Q(t) and roll R(t) respectively, Γ(t) is the combined rotation matrix, and t is any sampling time.

[0088] 2. Theoretical delay calculation

[0089] First, the coordinates of each array element in the local level coordinate system are obtained by combining the rotation matrix as follows.

[0090]

[0091] where the three-dimensional coordinate vector of the mth row and nth column in the local level coordinate system is A′ m，n = [x′ m，n y′ m，n z′ m，n ] T , the three-dimensional coordinate vector of the mth row and nth column in the carrier coordinate system is A m，n = [x m，n y m，n z m，n ] T , and the superscript T denotes the transpose of the vector.

[0092] Then, the angle θ m，n between the vector A′ l and the beamforming pointing angle unit vector B m，n，l (l is the beamforming pointing angle sequence number) is calculated, denoted as

[0093]

[0094] where |·| is the vector norm. The pitch angle is α l , and the azimuth angle is β l ​beamforming pointing angle unit vector B l may be expressed as

[0095] B l = [cosα l cosβ l cosα l sinβ l sinα l ] T

[0096] Finally, the theoretical delay of each array element under the lth pointing angle is calculated by the included angle between two vectors as:

[0097]

[0098] where c is the sound speed.

[0099] 3. Delay compensation value calculation

[0100] According to the delay τ m，n，l , the address offset is obtained by rounding according to the current signal sampling rate:

[0101]

[0102] where is the rounding operation, f s is the digital signal sampling rate.

[0103] 4. Phase compensation value calculation

[0104] The phase remaining after delay compensation needs to be further compensated as:

[0105] p′ m，n，l = 2πf s (τ m，n，l -D m，n，l / f s ) (1)

[0106] 5. Sampling and preprocessing

[0107] Sampling usually needs to be completed by an analog-to-digital converter, and digital band-pass filtering or demodulation and other preprocessing operations are implemented, and the complex signal of each array element obtained is S m，n (i), where i is the sampling point serial number.

[0108] 6. Delay compensation processing

[0109] The delay compensation processing is performed on the signal with D m，n，l as the address offset, and the processed signal can be expressed as

[0110] S′ m，n，l (i) = Sm，n (i-D m，n，l ) (2)

[0111] 7、Phase shift compensation processing

[0112] Further accurate compensation is made to the signal by using the phase compensation value, and the compensation result is

[0113]

[0114] where j is a unit of imaginary part, and e is Euler number. According to the Hilbert transform of formula (1) and formula (2), the above formula can be rewritten as

[0115]

[0116] where, is the Hilbert transform of S m，n (i).

[0117] 8、Weighted summation processing

[0118] After the delay and phase shift, each channel data is multiplied by a weighting coefficient k m，n and then summed. For an M*N uniform planar array, the lth beamformed signal is represented as follows

[0119]

[0120] If the weighting coefficient k m，n is constant, according to formula (3), the above formula can be rewritten as

[0121]

[0122] That is, the signal gain after beamforming is M*N times.

[0123] III. Comparison of calculation amount

[0124] Now taking a narrowband signal with a sampling rate of 2.5 times the bandwidth as the system input, the number of multiplications per second in each processing step is counted to analyze the calculation complexity of the delay and phase compensation method (method one), the phase beamforming method (method two), and the 30 times sampling rate delay beamforming method (method three). See Table 1.

[0125] Table 1 Analysis of calculation complexity of three methods

[0126]

[0127] where B0 is the signal bandwidth, and the 6 times upsampling of method three can meet the requirements, and the upsampling filter is taken as 256 order.

[0128] From Table 1, it can be seen that the calculation amount consumed by Method 3 is much greater than that of the other two methods. In an actual processing system, the addressing operation in the delay beam forming also consumes certain calculation time. Compared with Method 2, Method 1 needs to increase a part of addressing time, but it is far less than the addressing time of Method 3. Here, the specific statistics and comparison are not made in the table.

[0129] IV. Simulation results and analysis

[0130] The simulation compares the advantages and disadvantages of the three beam forming methods. The parameters used in the simulation are as follows:

[0131] (1) Signal form: short pulse;

[0132] (2) Signal sampling rate: 2.5B0;

[0133] (3) Number of array elements: 8*16;

[0134] (4) Beam forming theoretical gain: 128;

[0135] (5) Weighting coefficient: constant 1;

[0136] (6) Signal-to-noise ratio: 15dB;

[0137] (7) Aperture filling factor: calculated using appropriate pulse width and array length.

[0138] According to the above parameters, the time domain results of the beam forming of the three methods, the influence of the aperture filling factor on the beam forming gain, and the influence of the beam forming angle on the beam forming gain are simulated respectively. The simulation results and analysis are as follows:

[0139] Figure 3 and Figure 4 respectively show the time domain graphs of the beam forming results of the three methods when R=0.64 and R=2.56, wherein the beam pointing angle is 60°. It can be seen that Method 1 and Method 3 have approximately the same output waveform, and the gain is close to the theoretical gain 128. When the aperture filling factor R is small, Method 2 also has good output waveform and gain, but the pulse peak position duration becomes shorter, and there is a certain pulse spreading phenomenon. When the aperture filling factor R is large, the gain of Method 2 is significantly reduced, and the pulse spreading phenomenon is obvious, and the predetermined array gain and beam forming effect cannot be achieved.

[0140] To investigate the influence of different aperture filling factors on the beam forming gain, Figure 5To fill the aperture coefficient for the influence of beamforming gain, the simulation results of three methods are given, wherein the beam pointing angle is 60°. The results show that the method two and the method one are close to the theoretical gain 128. But with the increase of aperture filling coefficient, the gain of method two deteriorates rapidly. When the aperture filling coefficient is about 2, the beamforming gain is only half of the theoretical value, at this time the beamforming method is not suitable for the array system. With the increase of aperture filling coefficient, the gain of method one decreases slowly and always keeps a high beamforming gain.

[0141] Under the condition of the same aperture filling coefficient, Figure 6 To the influence of beamforming pointing angle on gain, the gain effect of different beam pointing angles when R=5 is shown. The results show that under the condition of different pointing angles, the method two and the method one are close to the theoretical gain 128. When the beam pointing is perpendicular to the array, such as within 10°, the gain of method two can meet the requirements, but with the increase of beam pointing angle, the gain effect of method two deteriorates rapidly. In comparison, the beamforming gain of method one is less affected by the beam deflection, and has strong applicability.

[0142] The simulation results show that the method proposed in the application has similar gain with the traditional delay beamforming method, and when there is aperture filling effect, the method is superior to the phase beamforming method.

[0143] Embodiment 2

[0144] The embodiment 2 of the application designs a delay and phase compensation beamforming system, the system comprises: an array and a signal processing module, wherein,

[0145] The array comprises a plurality of array elements, each array element is used for receiving a signal;

[0146] The signal processing module is used for calculating the theoretical delay value to be applied to the signal of each array element by using the position coordinates of each array element in the array and the beamforming direction; is used for quantizing the theoretical delay value, calculating the address offset of each array element, calculating the delay compensation value by using the address offset, and calculating the difference between the delay compensation value and the theoretical delay value as the phase compensation value of the signal received by the array element; is used for sampling and preprocessing the signal received by each array element to obtain a complex signal, and sequentially performing addressing operation and phase shift operation on the complex signal according to the calculated address offset and phase compensation value; and is further used for weighting and accumulating the signal after the phase shift operation, and finally outputting the beamforming data.

[0147] Finally, it should be noted that the above examples are merely used to illustrate the technical solutions of the present application but not to limit. Although the present application is explained in detail with reference to the examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A time delay and phase compensation beam forming method, the method comprising: Step 1. calculating a theoretical time delay value to be applied to a signal of each array element based on a position coordinate of each array element in the array and a beam forming direction; Step 2. quantizing the theoretical time delay value to calculate an address offset of each array element, calculating a time delay compensation value based on the address offset, and calculating a difference between the time delay compensation value and the theoretical time delay value as a phase compensation value of a signal received by the array element; Step 3. sampling and pre-processing a signal received by each array element to obtain a complex signal, and sequentially performing addressing operation and phase shift operation on the complex signal based on the calculated address offset and phase compensation value; Step 4. performing weighting processing on the signal after the phase shift operation, and accumulating to finally output beam forming data; wherein the Step 1 specifically comprises: Step 1-1. calculating a position coordinate of each array element in a local coordinate system based on a position coordinate of each array element in a carrier coordinate system; Step 1-2. calculating an included angle between a position coordinate vector of each array element in the carrier coordinate system and a corresponding beam forming pointing angle unit vector; Step 1-3. calculating a theoretical time delay of each array element at the lth pointing angle based on the included angle; In step 1-1, a three-dimensional coordinate system for the carrier is established, with the port side as the positive y-axis, the bow direction as the positive x-axis, and the sky direction as the positive z-axis. For time t, the roll angle R(t) is positive when the port side is raised, the pitch angle P(t) is positive when the bow is raised, and the bow angle... A starboard yaw is positive; for an M*N array, the position coordinates of the element in the m-th row and n-th column in the local coordinate system are... The formula for calculation is: where Γ(t) represents the yaw rotation matrix of the ship the rotation matrix of the three directions of the pitch P(t), the roll R(t) Γ P (t), Γ R (t) and the synthetic rotation matrix, represents the position coordinates of the element in the mth row and the nth column in the carrier coordinate system; m = 1, 2, 3, …, M; n = 1, 2, 3, …, N. In the step 1-2, the position coordinate vector A' of the element in the mth row and the nth column in the local coordinate system m,n = [x' m,n y' m,n z' m,n ] T ; the superscript T is the transpose of the vector; In the steps 1-2, the position coordinate vector A' of the element in the mth row and the nth column in the local coordinate system m,n and the included angle θ between the beam forming pointing angle unit vector B l m,n,l The calculation formula is:​ wherein; l is the beamforming pointing angle index; |·| operation is the vector modulus; B l represents the beamforming pointing angle unit vector with the pitch angle of α l and the azimuth angle of β l , which is shown as follows: B l = [cosα l cosβ l cosα l sinβ l sinα l ] T In the steps 1-3, the theoretical delay τ of the element in the mth row and the nth column under the lth pointing angle m,n,l The calculation formula is: wherein c is a sound speed.

2. The method of claim 1, wherein, the yawing the rotation matrix in the three directions of the yaw P(t), the roll R(t) and the pitch Γ P the calculation formula of the yawing angle R the calculation formula of the roll angle The calculation of the rotation matrix Γ(t) is:

3. The method of claim 1, wherein, In the Step 2, the theoretical time delay value is quantized to calculate the address offset of each array element, specifically comprising: The theoretical delay value of each array element is rounded according to the signal sampling rate to obtain the address offset of each array element, wherein the address offset D of the array element in the mth row and the nth column is calculated as follows: m,n,l D = (m-1) * N + (n-1) wherein, is a rounding operation, f s is the signal sampling rate; The phase compensation value p' of the received signal of the element in the mth row and the nth column m,n,l The calculation formula is: p' m,n,l = 2πf s (τ m,n,l -D m,n,l / f s ).

4. The method of claim 1, wherein, In the Step 3, the signal received by each array element is sampled and pre-processed to obtain a complex signal, wherein the sampling is completed by an analog-to-digital converter, and the pre-processing includes digital band-pass filtering or demodulation.

5. The method of claim 1, wherein, a complex signal S for the mth row, nth column array element m,n (i) a signal S' obtained after the addressing operation m,n,l (i) is expressed as S' m,n,l (i) = S m,n (i-D m,n,l ) wherein i is a sampling point serial number; to the signal S' m,n,l (i) the signal S" after the phase shift operation m,n,l (i) is expressed as wherein S is S m,n the Hilbert transform of (i), H denotes the conjugate transpose; for a uniform planar array of M*N, the lth beam forming signal is represented as follows where k m,n is a weighting factor.

6. The method of claim 5, wherein, In step 4, the final output beamformed signal is output, where the lth output beamformed signal U l (t) is: that is, the signal gain after beam forming is M*N times.

7. A delay and phase compensated beamforming system, characterized by, The system comprises: an array and a signal processing module, wherein the array comprises a plurality of array elements, each array element being configured to receive a signal; the signal processing module is configured to calculate a theoretical time delay value to be applied to a signal of each array element based on a position coordinate of each array element in the array and a beam forming direction, to quantize the theoretical time delay value to calculate an address offset of each array element, to calculate a time delay compensation value based on the address offset, and to calculate a difference between the time delay compensation value and the theoretical time delay value as a phase compensation value of a signal received by the array element, to sample and pre-process a signal received by each array element to obtain a complex signal, and to sequentially perform addressing operation and phase shift operation on the complex signal based on the calculated address offset and phase compensation value, and to perform weighting processing on the signal after the phase shift operation, and to accumulate to finally output beam forming data; wherein the calculation of the theoretical time delay value based on the position coordinate of each array element in the array and the beam forming direction specifically comprises: Step 1-1. calculating a position coordinate of each array element in a local coordinate system based on a position coordinate of each array element in a carrier coordinate system; Step 1-2. calculating an included angle between a position coordinate vector of each array element in the carrier coordinate system and a corresponding beam forming pointing angle unit vector; Step 1-3. calculating a theoretical time delay of each array element at the lth pointing angle based on the included angle; In the step 1-1, a carrier three-dimensional coordinate system is established, the port direction is the positive direction of the y axis, the carrier head direction is the positive direction of the x axis, and the sky direction is the positive direction of the z axis. For t time, the roll angle R(t) is positive when the port is raised, the pitch angle P(t) is positive when the carrier head is raised, the yaw angle H(t) is positive when the bow is deflected to the right, and the yaw angle H(t) is positive when the bow is deflected to the right. For an array of M*N, the position coordinates of the mth row and nth column element in the local coordinate system are The calculation formula is: where Γ(t) represents the yaw rotation matrix of the ship the rotation matrix of the three directions of the pitch P(t), roll R(t) Γ P (t), Γ R (t) and the synthetic rotation matrix, represents the position coordinates of the element in the mth row and the nth column in the carrier coordinate system; m = 1, 2, 3, …, M; n = 1, 2, 3, …, N. In the steps 1-2, the position coordinate vector A' of the element in the mth row and the nth column in the local coordinate system m,n = [x' m,n y' m,n z' m,n ] T ; the superscript T is the transpose of the vector; In the steps 1-2, the position coordinate vector A' of the element in the mth row and the nth column in the local coordinate system m,n and the included angle θ between the beam forming pointing angle unit vector B l m,n,l The calculation formula is:​ wherein; l is the beamforming pointing angle index; |·| operation is the vector modulus; B l denotes the beamforming pointing angle unit vector with the pitch angle α l and the azimuth angle β l , which is shown as follows: B l = [cosα l cosβ l cosα l sinβ l sinα l ] T In the steps 1-3, the theoretical delay τ of the element in the mth row and the nth column under the lth pointing angle m,n,l The calculation formula is: where c is the speed of sound.

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