CN114265058A

CN114265058A - MIMO radar target angle measurement method and device, electronic equipment and storage medium

Info

Publication number: CN114265058A
Application number: CN202111519366.6A
Authority: CN
Inventors: 蒋梦杰; 王震; 孙旭旭; 林泽阳; 郭坤鹏; 冯友怀; 张燎
Original assignee: China Automotive Innovation Corp; Nanjing Hawkeye Electronic Technology Co Ltd
Current assignee: China Automotive Innovation Corp; Nanjing Hawkeye Electronic Technology Co Ltd
Priority date: 2021-12-13
Filing date: 2021-12-13
Publication date: 2022-04-01
Anticipated expiration: 2041-12-13
Also published as: CN114265058B

Abstract

The invention provides a method and a device for measuring an angle of an MIMO radar target, electronic equipment and a storage medium, wherein the method comprises the following steps: designing an array according to the number of transmitting antennas, the number of receiving antennas, azimuth resolution, elevation resolution, azimuth FOV and elevation FOV; acquiring azimuth channel data, elevation channel data and angle matching array channel data from the azimuth virtual linear array, the elevation virtual linear array and the angle matching array, and respectively performing azimuth angle estimation and elevation angle estimation on the basis of the azimuth channel data and the elevation channel data to obtain an azimuth angle set and an elevation angle set; combining angle elements in the azimuth angle set and angle elements in the pitching angle set to obtain a joint angle; and performing matching judgment on at least one group of joint angles based on the angle matching array channel data to obtain the azimuth angle and the pitch angle corresponding to the target. The invention can accurately obtain the azimuth angle and the pitch angle corresponding to the target.

Description

MIMO radar target angle measurement method and device, electronic equipment and storage medium

Technical Field

The invention relates to the technical field of radars, in particular to a method and a device for measuring an angle of an MIMO radar target, electronic equipment and a storage medium.

Background

At present, a multi-chip cascade MIMO (Multiple-Input Multiple-Output) technology is mostly adopted for vehicle-mounted and traffic radars, high resolution can be realized in azimuth angle and pitch angle dimensions, high-quality three-dimensional point cloud images are provided, and application scenes of the vehicle-mounted and traffic radars are greatly expanded. The design of the array and the angle measurement method are the key points of the design of the multi-chip cascade MIMO radar system. In order to effectively reduce the angle measurement complexity of the high-resolution radar and obtain an accurate angle measurement result, the invention provides a target angle measurement method of the MIMO radar.

Disclosure of Invention

The invention provides a method and a device for measuring an angle of an MIMO radar target, electronic equipment and a storage medium, which are used for solving the problems that the radar lacks pitch angle observation and obtains an accurate angle measurement result in the prior art.

In a first aspect, an embodiment of the present invention provides a method for measuring an angle of a MIMO radar target, where the method includes:

constructing azimuth virtual linear arrays, elevation virtual linear arrays and angle matching arrays containing target azimuth information and elevation angle information according to the number of preset transmitting antennas, the number of preset receiving antennas, azimuth resolution, elevation resolution, azimuth FOV and elevation FOV;

acquiring azimuth channel data, elevation channel data and angle matching array channel data from the azimuth virtual linear array, the elevation virtual linear array and the angle matching array, and respectively performing azimuth angle estimation and elevation angle estimation on the basis of the azimuth channel data and the elevation channel data to obtain an azimuth angle set and an elevation angle set;

combining the angle elements in the azimuth angle set and the angle elements in the pitch angle set to obtain at least one group of joint angles;

and performing matching judgment on the at least one group of joint angles based on the angle matching array channel data to obtain an azimuth angle and a pitch angle corresponding to the target.

In an embodiment of the present invention, constructing an azimuth virtual line array, a pitch virtual line array, and an angle matching array including target azimuth information and pitch angle information according to a preset number of transmitting antennas, a preset number of receiving antennas, an azimuth resolution, a preset pitch resolution, an azimuth FOV, and a preset pitch FOV includes:

respectively calculating the aperture of the azimuth virtual linear array and the aperture of the pitching virtual linear array according to the preset azimuth resolution and pitch resolution;

determining a first array element spacing representing the array element position spacing of the azimuth virtual linear array according to the azimuth FOV, and determining a second array element spacing representing the array element position spacing of the pitching virtual linear array according to the pitching FOV;

determining the number of azimuth virtual array elements and the number of elevation virtual array elements based on the first array element spacing, the second array element spacing, the azimuth virtual linear array aperture and the elevation virtual linear array aperture;

determining the maximum number of virtual array elements of a virtual array based on the number of the transmitting antennas and the number of the transmitting antennas, wherein the maximum number of virtual array elements is the product of the number of the transmitting antennas and the number of the transmitting antennas;

determining the number of redundant array elements of the virtual array based on the maximum number of virtual array elements of the virtual array, the number of azimuth virtual array elements and the number of pitching virtual array elements;

and designing the angle matching matrix based on the number of the redundant array elements and by utilizing the redundant array elements.

In an embodiment of the present invention, the calculating the aperture of the azimuth virtual linear array and the aperture of the elevation virtual linear array according to the preset azimuth resolution and the preset pitch resolution respectively includes:

calculating the azimuth virtual linear array aperture and the elevation virtual linear array aperture according to the following formula:

wherein L is_azimuthIndicating the azimuth virtual line array aperture, L_pitchDenotes the pitch virtual line array aperture, λ denotes the wavelength, Δ θ₁Indicating a predetermined azimuthal resolution, Δ θ₂Representing a preset pitch resolution, theta₁Is a preset direction angle value theta₂Is a preset pitch angle value.

In an embodiment of the present invention, said determining an azimuth view and a pitch view based on said first array element spacing and said second array element spacing comprises:

determining the first array element spacing and the second array element spacing according to the following formula:

wherein the FOV_azimuthRepresents the azimuthal view range, | FOV_azimuthI denotes FOV_azimuthMaximum positive azimuth, FOV_elevationRepresents the range of elevation view, | FOV_elevationI denotes FOV_elevationThe maximum positive pitch angle, λ represents the wavelength, xbase represents the first array element spacing, and ybase represents the second array element spacing.

In an embodiment of the present invention, the acquiring azimuth channel data, elevation channel data, and angle matching array channel data from the azimuth virtual linear array, the elevation virtual linear array, and the angle matching array includes:

acquiring collected echo data of a frame;

distinguishing data of each channel according to the frame of echo data;

for each channel, performing range-Doppler imaging processing on data corresponding to the channel to obtain a range-Doppler image corresponding to the channel;

respectively carrying out incoherent accumulation and constant false alarm detection processing on the range-doppler image corresponding to each channel data to obtain a range-doppler unit corresponding to at least one target;

and acquiring azimuth channel data, elevation channel data and angle matching array channel data corresponding to each range-Doppler unit.

In an embodiment of the present invention, the performing, based on the azimuth channel data and the pitch channel data, azimuth angle estimation and pitch angle estimation respectively to obtain an azimuth angle set and a pitch angle set includes:

calculating an azimuth guiding vector according to the first array element distance, and performing digital beam forming processing on the azimuth guiding vector and the azimuth channel data to obtain an azimuth angle spectrum; or directly carrying out Fourier transform processing on the azimuth channel data to obtain an azimuth spectrum;

and carrying out constant false alarm detection on the azimuth angle spectrum to obtain the azimuth angle set.

In an embodiment of the present invention, the performing, based on the azimuth channel data and the pitch channel data, azimuth angle estimation and pitch angle estimation respectively to obtain an azimuth angle set and a pitch angle set further includes:

calculating a pitching guide vector according to the second array element interval, and performing digital beam forming processing on the pitching guide vector and the pitching channel data to obtain a pitching angle spectrum; or directly carrying out Fourier transform processing on the pitching channel data to obtain a pitching angle spectrum;

and carrying out constant false alarm detection on the pitch angle spectrum to obtain the pitch angle set.

In an embodiment of the present invention, the determining that the at least one group of joint angles are matched based on the angle matching array channel data to obtain an azimuth angle and a pitch angle corresponding to the target includes:

determining that each joint angle corresponds to a target under the condition that the number of the at least one group of joint angles is equal to the number of different joint angles obtained by randomly matching the elements of the azimuth angle set and the elements of the pitch angle set;

in the case where the number of the at least one set of joint angles is greater than the maximum of the number of elements of the azimuth angle set and the number of elements of the pitch angle set, performing the following operations:

determining all joint angle association sets, wherein each joint angle association set comprises associated joint angle combinations, and each joint angle combination comprises two joint angles;

aiming at each joint angle combination, simultaneously substituting the azimuth angle and the pitch angle of each joint angle in the joint angle combination into a steering vector expression of an angle matching array to obtain a steering vector corresponding to the joint angle combination;

aiming at each joint angle combination, performing angle domain digital beam forming processing on the corresponding steering vector and the channel data of the angle matching array;

and summing the digital beam forming results corresponding to the combined angle combinations in each combined angle association set, and respectively taking the azimuth angle and the pitch angle indicated by the two combined angles in the combined angle set with larger sum value as the azimuth angle and the pitch angle of the two corresponding targets.

In one embodiment of the present invention, the steering vector expression of the angle matching array is determined by:

α(θ,φ)＝exp(j·2π·(D_Azi·sinθ+D_Ele·sinφ)/λ)；

wherein α (θ, φ) represents a directorQuantity, theta for azimuth, phi for pitch, D_AziIndicating the azimuthal physical separation, D_EleDenotes the physical pitch, λ denotes the wavelength, and j denotes the complex sign of the phase.

In one embodiment of the invention, the azimuthal physical distance D_AziAnd said physical pitch spacing D_EleRepresented by the formula:

wherein K represents the number of array elements of the angle matching array, d₁Array element spacing, d, representing the angular matching array mapping in azimuth₂And the array element spacing of the angle matching array mapping in the pitching direction is shown.

In one embodiment of the invention, the angular domain digital beamforming accumulation process is performed according to:

W＝conj(α(θ,φ))*DataK；

where W represents the result of the angle domain digital beamforming, conj represents the conjugate operation, and DataK represents the channel data of the angle matching array.

In a second aspect, the present invention also provides a MIMO radar target angle measurement apparatus, including:

the array construction module is used for constructing an azimuth virtual linear array, a pitching virtual linear array and an angle matching array containing target azimuth angle information and pitch angle information according to the preset number of transmitting antennas, the number of receiving antennas, azimuth resolution, pitch resolution, azimuth FOV and pitch FOV;

the estimation module is used for acquiring azimuth channel data, elevation channel data and angle matching array channel data from the azimuth virtual linear array, the elevation virtual linear array and the angle matching array, and respectively performing azimuth angle estimation and elevation angle estimation on the basis of the azimuth channel data and the elevation channel data to obtain an azimuth angle set and an elevation angle set;

the combination module is used for combining the angle elements in the azimuth angle set and the angle elements in the pitch angle set to obtain at least one group of combined angles;

and the matching module is used for performing matching judgment on the at least one group of joint angles based on the angle matching array channel data so as to obtain an azimuth angle and a pitch angle corresponding to the target.

In a third aspect, the present invention further provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the program, the steps of the MIMO radar target angle measurement method according to any one of the first aspect are implemented.

In a fourth aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, implements the steps of the MIMO radar target angle measurement method according to any one of the first aspect.

According to the MIMO radar target angle measurement method, the MIMO radar target angle measurement device, the electronic equipment and the storage medium, when the radar system detects that a plurality of azimuth angles and pitch angles exist at the position of the target, the angle matching array is constructed to judge different azimuth angles and pitch angle combinations, so that the azimuth angle and the pitch angle corresponding to the target can be accurately obtained.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other embodiments according to the drawings without creative efforts.

FIG. 1 is a schematic flow chart of a target angle measurement method provided by an embodiment of the invention;

FIG. 2(A) is a schematic flow chart of constructing an angle matching array according to an embodiment of the present invention;

FIG. 2(B) is a schematic diagram of an array provided by an embodiment of the present invention;

fig. 3 is a schematic flow chart illustrating a matching judgment performed by the angle matching array according to the embodiment of the present invention;

FIG. 4 is a schematic diagram of a range-Doppler image provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram of a 50 meter azimuth and elevation angle spectra provided by an embodiment of the present invention;

FIG. 6 is a schematic diagram of a 70 meter azimuth angle spectrum and a pitch angle spectrum provided by an embodiment of the present invention;

FIG. 7 is a schematic diagram of an 85 meter azimuth angle spectrum and a pitch angle spectrum provided by an embodiment of the present invention;

FIG. 8 is a schematic diagram of three-dimensional position coordinates of a real target and a detected target according to an embodiment of the present invention;

FIG. 9 is a schematic view of a target goniometer provided by an embodiment of the present invention;

fig. 10 is a schematic physical structure diagram of an electronic device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," and the like in the description and in the claims, and in the drawings described above, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein.

The technical terms to which the present invention relates are described below:

the MIMO (Multiple-Input Multiple-Output) technology is to use Multiple transmitting antennas and Multiple receiving antennas at a transmitting end and a receiving end, respectively, so that signals are transmitted and received through the Multiple antennas at the transmitting end and the receiving end, thereby improving communication quality. The space resources can be fully utilized, multiple sending and multiple receiving are realized through the multiple antennas, the system channel capacity can be improved in multiples under the condition that the frequency spectrum resources and the antenna transmitting power are not increased, the MIMO technology is applied to the radar and shows obvious advantages, and the method becomes a research hotspot of the current radar technology.

The target angle measuring method, the target angle measuring device and the electronic equipment can be applied to an MIMO radar, wherein the MIMO radar is a radar with a new system generated by introducing a multi-input multi-output technology in a wireless communication system into the field of radars and combining the multi-input multi-output technology with a digital array technology.

According to the MIMO radar target angle measurement method, the MIMO radar target angle measurement device, the electronic equipment and the storage medium, when the radar system detects that a plurality of azimuth angles and pitch angles exist at the position of a target, different azimuth angles and different pitch angle combinations are judged through the constructed angle matching array, and therefore the azimuth angle and the pitch angle corresponding to the target are obtained.

The MIMO radar target angle measurement method, apparatus, electronic device, and storage medium of the present invention are described below with reference to fig. 1 to 10.

Referring to fig. 1, fig. 1 is a schematic flow chart of a target angle measurement method according to an embodiment of the present invention, where the method according to the embodiment of the present invention includes:

step 101, constructing an azimuth virtual linear array, a pitching virtual linear array and an angle matching array containing target azimuth angle information and pitch angle information according to the number of preset transmitting antennas, the number of preset receiving antennas, the azimuth resolution, the pitch resolution, the azimuth FOV and the pitch FOV.

Illustratively, the purpose of constructing the angle matching array is to match different combinations of azimuth angles and pitch angles with corresponding targets when the radar system detects multiple targets at the same distance and speed. Since several targets are located at the same Range-Doppler cell in a Range-Doppler Image (Range-Doppler Image) in a case where a plurality of targets at the same distance and speed are detected by a radar system, it is necessary to distinguish different targets by a difference between an azimuth angle and a pitch angle.

For example, when the radar system detects two targets (a and B) at the same distance and speed, the target a and the target B may be distinguished by the azimuth angle and the pitch angle corresponding to the two targets, that is, the matching determination is performed by the angle matching array to obtain the azimuth angle and the pitch angle corresponding to the target a, and obtain the azimuth angle and the pitch angle corresponding to the target B.

102, acquiring azimuth channel data, elevation channel data and angle matching array channel data from the azimuth virtual linear array, the elevation virtual linear array and the angle matching array, and respectively performing azimuth angle estimation and elevation angle estimation based on the azimuth channel data and the elevation channel data to obtain an azimuth angle set and an elevation angle set.

Illustratively, assume that the set of azimuth angles obtained in the angle estimation is [ θ ]₁,θ₂,...,θ_N]The angle of pitch is integrated into

Thereby, the MN join angle can be obtained.

For example, the following description will be given taking as an example that there are at most two equidistant objects (in fact, there are two or more equidistant objects):

possibility 1: the number of azimuth angle estimates is 1, and the corresponding azimuth angle is represented by theta₁The number of pitch angle estimates is 1, and the corresponding pitch angle is expressed as

Then

The joint angle corresponding to one target is considered.

Possibility 2: azimuth angle estimationThe number is 2, corresponding to the set of azimuth angles [ theta ]₁，θ₂]The number of pitch angle estimates is 1, and the corresponding pitch angle is expressed as

Then

And

consider the joint angle of two targets.

Possibility 3: the number of azimuth angle estimates is 1, and the corresponding azimuth angle is represented by theta₁The number of pitch angle estimates is 2, and the corresponding pitch angle is expressed as

Then

And

consider the joint angle of two targets.

Possibility 4: the number of azimuth angle estimates is 2, and the corresponding azimuth angle is represented as [ theta ]₁，θ₂]The number of pitch angle estimates is 2, and the corresponding pitch angle is expressed as

Then the possible joint angle combinations of the two targets are

And

or

And

it should be noted that, the concept of joint angle association set, joint angle combination, and joint angle is exemplified as follows: joint angle association set (

And

) (ii) a Combination of angles (

And

) Or a combination of angles (

And

) (ii) a Combination angle

Or combined angle

Or combined angle

Or combined angle

It follows that the number of azimuth angle and pitch angle combinations is related to the set of azimuth angles and the set of pitch angles.

And 103, combining the angle elements in the azimuth angle set and the angle elements in the pitch angle set to obtain at least one group of joint angles.

For example, if a set of azimuth angle and pitch angle is obtained, it is the case of the above possibility 1, and this case is the case where the matching determination using the angle matching array is not required. Only when at least more than one group of joint angles of azimuth angles and pitching angles are obtained, the angle matching array is needed to be used for carrying out matching judgment on the combination. Examples of such combinations may refer to the above description of possibilities 1 to 4.

And 104, performing matching judgment on the at least one group of joint angles based on the angle matching array channel data to obtain an azimuth angle and a pitch angle corresponding to the target.

Exemplarily, the angle matching array is used for carrying out matching judgment on joint angles of different azimuth angles and different pitch angles, so that the azimuth angle and the pitch angle corresponding to the target are obtained.

For example, assume that of the above possibility 4: the number of azimuth angle estimates is 2, and the corresponding azimuth angle is represented by theta₁，θ₂(10.74,25.77), the estimated number of pitch angles is 2, and the corresponding pitch angle is shown as

(-2.236,6.273), then two target possible joint angles are:

and

i.e., [10.74, -2.236]，[25.77,6.273]，[10.74,6.273]，[25.77,-2.236]. Then, the angle matching array is used for carrying out matching judgment on the joint angles of different azimuth angles and different pitch angles, and the final result is assumed to be [ 10.74-2.236 ]]And [25.77, 6.273]The result of matching the angles of two targets at the same distance and speed, namely the azimuth angle and the pitch angle of one target are [10.74, -2.236]]Azimuth and pitch angles of another targetIs [25.77, 6.273]]。

The following is a detailed description of the above steps 101 to 104.

Referring to fig. 2(a), fig. 2(a) is a schematic flow chart of constructing an angle matching array according to an embodiment of the present invention. In step 101, the constructing an azimuth virtual linear array, a pitch virtual linear array, and an angle matching array including target azimuth information and pitch angle information according to the preset number of transmitting antennas, the preset number of receiving antennas, the preset azimuth resolution, the preset pitch resolution, the preset azimuth FOV, and the preset pitch FOV includes:

and 1011, respectively calculating the aperture of the azimuth virtual linear array and the aperture of the pitching virtual linear array according to the preset azimuth resolution and pitch resolution.

Because the angle resolution of the array is limited by the aperture of the array, signals or information at the position of the virtual array element can be constructed by the virtual array expansion technology, the aperture of the array is expanded, and the angle resolution is improved. The virtual array technology is to achieve the purposes of expanding the aperture of an original array or increasing the number of array elements and the like by some technical means including constructing a specific array structure model, processing a received signal source by a mathematical method, performing virtual transformation on the array and the like.

From the array virtual expansion method, the signal data of the virtual expansion array is actually the same as the received data model of the actual array, and the main difference between the two is array noise. That is, when the array is virtually extended, the noise on the extended array elements is generated by the matrix noise. Since the beam pattern of the extended array has a narrower main lobe and lower side lobes, the virtual extended array suppresses spatial noise more than the basic array. Therefore, the change of the signals and the noise before and after the virtual extension of the integrated array can obtain that the virtual extension of the array can effectively improve the output signal-to-noise ratio of the source signals.

Illustratively, the azimuth angle matching array aperture can also be referred to as an azimuth virtual line array aperture, and the elevation angle matching array aperture can also be referred to as an elevation virtual line array aperture.

Illustratively, the azimuth virtual line array aperture and the elevation virtual line array aperture are calculated according to the following formula:

And 1012, determining a first array element spacing representing the array element position spacing of the azimuth virtual linear array according to the azimuth FOV, and determining a second array element spacing representing the array element position spacing of the pitching virtual linear array according to the pitching FOV.

For example, by evaluating the resources of the transmitting antenna and the receiving antenna, the antenna resources are allocated to the azimuth direction and the elevation direction to determine the azimuth line array aperture and the elevation line array aperture, and further determine the array element spacing (also referred to as "antenna spacing") and the azimuth view angle range (Field of view, abbreviated as FOV) and the elevation view angle range (Field of view, abbreviated as FOV).

And 1013, determining the number of azimuth virtual array elements and the number of elevation virtual array elements based on the first array element spacing, the second array element spacing, the azimuth virtual line array aperture and the elevation virtual line array aperture.

Illustratively, the first array element spacing and the second array element spacing are determined according to the following equation:

wherein the FOV_azimuthRepresents the azimuthal view range, | FOV_azimuthI denotes FOV_azimuthMaximum positive azimuth, FOV_elevationIndicating the direction of pitchRange of viewing angle, | FOV_elevationI denotes FOV_elevationMaximum positive pitch angle, λ represents wavelength, xbase represents the first array element spacing (also referred to as "unit base length of the azimuth virtual array"), and ybase represents the second array element spacing (also referred to as "unit base length of the pitch virtual array").

For example, assuming that λ is 3.92mm, the base line length is 1.96mm, and the base line length is 7.8mm, the azimuth FOV and the pitch FOV of the azimuth line and the pitch line are calculated as follows:

according to the index requirements of the radar application scene, the base length of the azimuth direction and the base length of the pitch direction can be designed, but the influence of grating lobes and side lobes on the array angle measurement performance needs to be considered.

Array antennas are generally composed of two or more elementary radiation sources, i.e. composite antennas. Each radiation source is called an array element. The maximum radiation beam is called the main lobe and the beamlets beside the main lobe are called side lobes. The antenna radiation pattern typically has two or more lobes, with the lobe having the greatest radiation intensity being referred to as the main lobe and the remaining lobes being referred to as the side lobes or side lobes.

Except for the main lobe, the radiation lobes with the intensity similar to that of the main lobe are formed in other directions due to the fact that the field intensities are superposed in the same phase, and the radiation lobes are called as grating lobes. The grating lobes take up the radiated energy and reduce the antenna gain. Objects seen from the grating lobe are easily confused with objects seen from the main lobe, resulting in a blurred object position. Interference signals entering the receiver from the grating lobes will affect the proper operation of the communication system. Therefore, the array element spacing of the antenna should be reasonably selected to avoid grating lobes.

And 1014, determining the maximum number of virtual array elements of the virtual array based on the number of the transmitting antennas and the number of the transmitting antennas.

And the maximum virtual array element number is the transmitting antenna number.

Step 1015, determining the number of redundant array elements of the virtual array based on the maximum number of virtual array elements of the virtual array, the number of azimuth virtual array elements and the number of elevation virtual array elements, and designing the angle matching matrix based on the number of redundant array elements and by using the redundant array elements.

Fig. 2(B) is a schematic diagram of an array according to an embodiment of the present invention, and as can be seen from fig. 2(B), the azimuth array, the pitch array, and the angle matching array are independent from each other. The angle matching matrix of the present invention is not limited to the form shown in fig. 2(B), and may be non-uniform, but it should be ensured that the angle matching matrix is a linear array, i.e., the array elements are distributed on a straight line.

Illustratively, based on the array element spacing, the azimuth viewing angle and the elevation viewing angle, uniform linear arrays with corresponding apertures can be respectively constructed in the azimuth direction and the elevation direction.

Illustratively, the angle matching array is a 2-dimensional uniform linear array and is used for matching the azimuth angle and the pitch angle of multiple targets at the same distance and speed.

It should be noted that the MIMO radar can form a nyquist virtual array at the receiving end, which greatly improves the effective aperture of the array. The virtual array is not real, is an equivalent array, and is realized by matching a certain mathematical method with engineering time. The purpose of the virtual aperture is to improve the signal-to-noise ratio, i.e. to improve the detection capability of the radar. Since the angular resolution of a conventional array is determined by the array aperture, if it is desired to increase the angular resolution by a factor of 2, then it is required to be 2 times as long as the original array, but this can be achieved by a virtual array (i.e. an angle-matched array) in order to save costs.

The above step 102 is described in detail below.

In step 102, the obtaining of the azimuth channel data, the elevation channel data, and the angle matching array channel data from the azimuth virtual linear array, the elevation virtual linear array, and the angle matching array includes:

step 1021, acquiring a frame of acquired echo data.

The coded transmitting signals are radiated to the space through the radar transmitting antenna, when electromagnetic waves meet a target, echo signals generated by reflection reach a radar receiver through the radar receiving antenna, and are processed by the radar receiver and then sent to the signal processor for processing, so that target related parameters such as distance, direction, speed, shape and the like can be obtained.

For example, a single-pulse real-time acquisition and processing technology can be adopted to perform single-pulse real-time data acquisition on the echo signal of the measured target, store the acquired data result in a magnetic disk of a computer in real time, and perform post-data processing on the single-pulse real-time acquired data after the acquisition is finished.

And 1022, distinguishing data of each channel according to the frame of echo data.

Illustratively, after the echo data of one frame is collected, the channel data corresponding to the angle matching array is sequenced to obtain the azimuth direction, the pitch direction and the channel number corresponding to the angle matching array, so as to distinguish the channel data.

And 1023, performing range-doppler imaging processing on the data corresponding to each channel to obtain a range-doppler image corresponding to the channel.

The Range-Doppler (RD) imaging algorithm is a common method for performing Range and Doppler analysis on a target, FFT (fast Fourier transform) processing is performed on Range-dimensional (fast time) echo data, FFT processing is performed on Doppler-dimensional (slow time) echo data, and finally, in an obtained two-dimensional RD image, the Range of the target at the corresponding Range-Doppler unit position is obviously higher than that of other Range-Doppler units, and the Range-Doppler unit corresponds to the Range and speed information of the target.

And 1024, respectively performing incoherent accumulation and constant false alarm detection on the range-doppler image corresponding to each channel data to obtain a range-doppler unit corresponding to at least one target.

The radar has limited single pulse energy, and usually does not adopt a single received pulse to perform detection and judgment, and before judgment, a plurality of pulses need to be processed to improve the signal-to-noise ratio, and the processing method based on the plurality of pulses is accumulation.

The accumulation method is divided into coherent accumulation and non-coherent accumulation, wherein coherent accumulation means that the amplitudes of signals are superposed by using the phase relation between received pulses, and the method has the advantage that all radar echo energies can be directly added. The non-coherent accumulation is carried out after the signal envelope is taken, the information of the complex signal is lost at the moment, only the modulus is reserved, and the strict phase relation is not existed.

Constant False-Alarm Rate (CFAR) is a technique in which a radar system determines whether a target signal exists by discriminating between a signal output from a receiver and noise while keeping a False-Alarm probability Constant. Since noise (including atmospheric noise, artificial noise, internal noise, clutter, etc.) is certainly present at the receiver output, the signal is typically superimposed on the noise. This requires detection techniques to be used to determine whether the target signal is present in the noisy or signal-plus-noisy condition at the receiver output.

For example, the constant false alarm detection apparatus first processes the input noise to determine a threshold, compares the threshold with the input signal, and determines that there is a target if the input signal exceeds the threshold, or determines that there is no target otherwise.

And 1025, acquiring azimuth channel data, elevation channel data and angle matching array channel data corresponding to each range-doppler unit.

After the processing of the above step 1024, the position of the range-doppler cell corresponding to the target can be obtained, and the azimuth channel data, the elevation channel data, and the channel data of the angle matching array corresponding to the target range-doppler cell to be analyzed can be extracted therefrom.

The following is to perform estimation of an azimuth angle and a pitch angle respectively on the obtained azimuth channel data, pitch channel data, and channel data of the angle matching array, to obtain an azimuth angle set and a pitch angle set, and to perform specific description.

Exemplarily, in step 102, the performing azimuth angle estimation and pitch angle estimation based on the azimuth channel data and the pitch channel data, respectively, to obtain an azimuth angle set and a pitch angle set includes:

step 1026, calculating an azimuth guiding vector according to the first array element spacing, and performing Digital Beam Forming (DBF) processing on the azimuth guiding vector and the azimuth channel data to obtain an azimuth angle spectrum; or directly carrying out Fourier transform processing on the azimuth channel data to obtain an azimuth spectrum.

And step 1027, performing constant false alarm detection on the azimuth angle spectrum to obtain the azimuth angle set.

Therefore, the azimuth angle estimation is realized by performing DBF or FFT on azimuth channel data, the target position angle is represented as a peak value in an angle directional diagram, and then the azimuth angle of the position of the target is obtained through Constant False Alarm Rate (CFAR) detection.

Exemplarily, in step 102, the performing azimuth angle estimation and pitch angle estimation based on the azimuth channel data and the pitch channel data, respectively, to obtain an azimuth angle set and a pitch angle set further includes:

step 1028, calculating a pitch steering vector according to the second array element interval, and performing digital beam forming processing on the pitch steering vector and the pitch channel data to obtain a pitch angle spectrum; or directly carrying out Fourier transform processing on the pitching channel data to obtain a pitching angle spectrum;

and step 1029, performing constant false alarm detection on the pitch angle spectrum to obtain the pitch angle set.

Therefore, the pitch angle estimation also carries out DBF or FFT on the pitch channel data, and then the pitch angle of the position of the target is obtained through Constant False Alarm Rate (CFAR) detection.

Regarding the estimation of the azimuth angle and the elevation angle in the above steps 1026 to 1029, if DBF angle measurement is adopted, the antenna array beam is "steered" to one Direction for a period of time by performing weighted summation on the outputs of the array elements, and the steering position of the maximum output power is obtained for the desired signal, that is, DOA (Direction of Arriva, Direction of arrival positioning technology) estimation is given. The method is particularly operated to select a proper weighting vector for array output to compensate the propagation delay of each array element, so that the array output in a certain expected direction can be superposed in the same direction, a main lobe beam is generated in the direction of the array, small correspondence is generated in other directions, and the direction of a target signal can be determined by scanning the whole angle space by adopting a DBF method.

Therefore, when the DBF is performed in the azimuth direction and the pitch direction, the azimuth angle and the pitch angle are scanned, and the angle direction corresponding to the maximum output energy of the angle matching array is the angle direction of the target signal.

In addition, the azimuth array and the elevation array are designed into uniform linear arrays, and FFT processing can be directly performed on channel data, so that the same angle measurement effect of DBF processing is obtained.

The above step 103 is specifically described below.

When the azimuth angle and the pitch angle are estimated by the method, and a plurality of azimuth angles and pitch angles are detected, the angle elements in the azimuth angle set and the angle elements in the pitch angle set need to be combined to obtain at least one group of joint angles.

Therefore, the MN joint angle can be obtained, and the same-distance and same-speed targets are taken as two at most as an example for explanation:

Then

The joint angle of the target is considered.

Possibility 2: the number of azimuth angle estimates is 2, and the corresponding azimuth angle is represented by theta₁，θ₂The number of pitch angle estimates is 1, and the corresponding pitch angle is expressed as

Then

And

consider the joint angle of two targets.

Then

And

consider the joint angle of two targets.

Possibility 4: the number of azimuth angle estimates is 2, and the corresponding azimuth angle is represented by theta₁，θ₂The number of pitch angle estimates is 2, and the corresponding pitch angle is expressed as

Then the possible joint angle combinations of the two targets are

And

or

And

the above step 104 is described in detail below.

Referring to fig. 3, fig. 3 is a schematic flow chart illustrating a matching determination performed by the angle matching array according to the embodiment of the present invention. In step 104, the determining that the at least one group of joint angles are matched based on the angle matching array channel data to obtain the azimuth angle and the pitch angle corresponding to the target includes:

in case the number of said at least one set of joint angles is greater than the maximum of the number of elements of said azimuth angle set and the number of elements of said pitch angle set (for example in the case of the above possible 4), the following operations are performed:

step 1041, determining all joint angle association sets, each joint angle association set comprising associated joint angle combinations, each joint angle combination comprising two joint angles.

Illustratively, the associated joint angle combinations may be two or more, for example, when one object is detected to contain two or more equidistance and same speed objects, then the associated joint angle combinations may be two or more.

Illustratively, each of the joint angle combinations contains two joint angles, since the target has only azimuth and pitch angles corresponding to it.

And 1042, aiming at each joint angle combination, simultaneously substituting the azimuth angle and the pitch angle of each joint angle in the joint angle combination into a steering vector expression of the angle matching array to obtain a steering vector corresponding to the joint angle combination.

Illustratively, the steering vector expression for the angle-matched array is determined by:

α(θ,φ)＝exp(j·2π·(D_Azi·sinθ+D_Ele·sinφ)/λ)；

wherein α (θ, φ) represents a steering vector, θ represents an azimuth angle, φ represents a pitch angle, D_AziIndicating the azimuthal physical separation, D_EleDenotes the physical pitch, λ denotes the wavelength, and j denotes the complex sign of the phase.

It should be noted that:

(1) the steering vector of the azimuth linear array is as follows:

α(θ)＝exp(j·2π·D_Azisin θ/λ), but α (θ) is only related to the azimuth angle θ and not to the pitch angle φ.

(2) The guide vector of the pitching linear array is as follows:

α(φ)＝exp(j·2π·D_Elesin phi/lambda), but alpha (phi) is only related to the pitch angle phi and not to the azimuth angle theta.

(3) The steering vector of the angle-matched array is:

α(θ,φ)＝exp(j·2π·(D_Azi·sinθ+D_Elesin phi)/lambda), and alpha (theta, phi) is related to both the azimuth angle theta and the pitch angle phi.

Illustratively, the azimuthal physical separation D_AziAnd said physical pitch spacing D_EleRepresented by the formula:

Step 1043, for each joint angle combination, performing angle domain digital beam forming processing on the corresponding steering vector and the channel data of the angle matching array.

Illustratively, the angular domain digital beamforming process is performed according to:

W＝conj(α(θ,φ))*DataK；

Step 1044 of summing the digital beam forming results corresponding to the joint angle combinations in each joint angle association set, and taking the azimuth angle and the pitch angle indicated by the two joint angles in the joint angle set with the larger sum value as the azimuth angle and the pitch angle of the corresponding two targets respectively.

For example, for the above "possibility 4" example, when performing DBF processing on the channel data of the angle matching array, the above 4 joint angle association sets are used (b

And

) And scanning to obtain main lobe amplitudes corresponding to different joint angle correlation sets, and taking one group with the maximum DBF amplitude summation result in the two groups of joint angle correlation sets as a joint angle corresponding to the two targets.

E.g. in two sets of joint angles

And

the sum of (1) is 100, and in both sets of joint angles

And

if the summation results are all 10, a group of joint angles with larger accumulation values in the DBF amplitude summation results are selected

And

as the joint angle corresponding to the two targets, the azimuth angle and the pitch angle corresponding to the target 1 are obtained

The azimuth angle and the pitch angle corresponding to the target 2 are

The following describes a process of performing matching judgment on the joint angle correlation set by using an angle matching array according to an application embodiment.

The first embodiment is as follows:

considering the case of the same-distance and same-speed multiple targets, when several targets are located at the same Range-Doppler cell position in the Range-Doppler Image (Range-Doppler Image), the different targets can be distinguished only by the angular difference of the targets, that is, the multiple same-distance and same-speed targets have the difference of azimuth angles or pitch angles, thereby distinguishing the different targets (if the azimuth angles and the pitch angles of the same-distance and same-speed targets are adjacent, the two targets cannot be distinguished in one angle resolution cell).

Assuming that the number of array elements in the azimuth direction is M and the number of array elements in the pitch direction is N, M pieces of channel data can be used for azimuth angle measurement, and N pieces of channel data can be used for pitch angle measurement. Assuming that two targets with the same speed (i.e. the same-distance and same-speed targets) exist on a certain range bin, the two targets are in the same range-doppler cell in the range-doppler image, four targets are set, and the range-speed angle information is shown in table one:

watch 1

Target serial number	Distance (m)	Speed (m/s)	Azimuth angle (°)	Angle of pitch (°)	Remarks for note
						1	50	10	11	-2	Same distance and same speed
2	50	10	26	6	Same distance and same speed
						3	70	20	11	-3
4	85	-15	-21	5

Two targets with a distance of 50 meters can be found to be the same-distance and same-speed targets, and a two-dimensional FFT is performed on the echo data of the targets to obtain a range-Doppler image as shown in FIG. 4. The square frame shown in fig. 4 is a same-distance and same-speed target located in the same range-doppler cell, and it can be known from the figure that the same-distance and same-speed target is located in the same range-doppler cell position in the range-doppler image, and the number of targets can be determined by further analyzing the azimuth angle and the pitch angle.

Therefore, the number of targets cannot be distinguished only by the range-velocity information, data corresponding to the target range-doppler cells of each channel needs to be extracted to perform the next angle measurement, and Digital Beam Forming (DBF) or FFT is performed on the azimuth target channel data to obtain an angle spectrum corresponding to the azimuth target, as shown in fig. 5. Fig. 5 shows a schematic of the azimuth and elevation angular spectra of a target at 50 meters. It can be seen that the same-range, same-velocity targets (different in spatial location, i.e., different in angle) that cannot be distinguished in the range-doppler image (i.e., fig. 4) can be distinguished in the azimuthal and elevation angular spectra shown in fig. 5, i.e., having two peaks representing two targets. Therefore, the number of targets can be determined by the azimuth angle spectrum and the elevation angle spectrum, for example, fig. 5 can determine that the number of targets is 2, that is, corresponding to target 1 and target 2 in table one.

Referring to fig. 6 and 7 again, fig. 6 is a schematic diagram of an azimuth angle spectrum and a pitch angle spectrum of 70 meters provided by an embodiment of the present invention, and fig. 7 is a schematic diagram of an azimuth angle spectrum and a pitch angle spectrum of 85 meters provided by an embodiment of the present invention. Fig. 6 shows that there is only one peak in the angular spectrum of azimuth and elevation, and only one target, target 3, corresponding to table one. Fig. 7 shows that there is only one peak in the angular spectrum of azimuth and elevation, and only one target, target 4, corresponding to table one.

As can be seen from fig. 5 to 7, when there is no object at the same distance and speed, the range-doppler cell has only one peak in the angle spectrum obtained by DBF/FFT processing of the channel data.

And after the number of the targets is identified through the azimuth angle spectrum and the pitch angle spectrum, matching judgment of the azimuth angle and the pitch angle of the targets is carried out.

As can be seen from fig. 4 and 5, two targets at 50 m positions can be set as a and B, the distance and the speed of the target a and the target B are the same, but the angles are different, the distance and the speed information of the target can be obtained from the position of the range-doppler cell corresponding to the target in the range-doppler image, the azimuth angle of the target a and the target B is 10.74 or 25.77 (but the azimuth angles of the target a and the target B are not distinguishable) can be obtained from fig. 5, and similarly, the pitch angle of the target a and the target B is-2.236 or 6.273. Several possibilities are thus available:

possibility 1: the azimuth/pitch angle of A is [10.74, -2.236], and the azimuth/pitch angle of B is [25.77, 6.273 ].

Possibility 2: the azimuth/pitch angle of A is [10.74,6.273], and the azimuth/pitch angle of B is [25.77, -2.236 ].

Possibility 3: the azimuth/pitch angle of A is [25.77, 6.273], and the azimuth/pitch angle of B is [10.74, -2.236 ].

Possibility 4: the azimuth/pitch angle of A is [25.77, -2.236], and the azimuth/pitch angle of B is [10.74,6.273 ].

It can be found that possibilities 3 and 4 are duplicated with possibilities 1 and 2, but do not affect the final detection result. Thus, there are only four possible combined azimuth/elevation angles: [10.74, -2.236],[25.77,6.273],[10.74,6.273],[25.77, -2.236].

How to find the most probable angle combination as the angle detection result of the target A, B is one of the inventions of the present invention.

The principle of DBF, similar to the FFT principle, is that when the actual channel data is compensated by the optimal weight vector, the accumulation of signals can be obtained, and thus the signal appears as a peak on the angular domain spectrum, and the above-mentioned angular combination can be determined by using this principle.

The angle matching array comprises two-dimensional information of azimuth and elevation, and the guide vector of the angle matching array is expressed as follows:

α(θ,φ)＝exp(j·2π·(D_Azi·sinθ+D_Ele·sinφ)/λ)； (1)

wherein α (θ, φ) represents the steering vector of the angle-matched array, θ represents the azimuth angle, φ represents the pitch angle, D_AziDenotes the azimuthal physical spacing of the angle-matched array, D_EleDenotes the physical pitch of the angle-matched array, λ denotes the wavelength, and j denotes the complex sign of the phase.

Azimuthal physical spacing D of the angle-matched array_AziAnd the physical pitch D of the angle matching array_EleExpressed as:

When the corresponding angle combination is substituted into the formula (1), 4 groups of guide vectors corresponding to different angles are obtained:

α(10.74,-2.236)，α(25.77，6.273)，α(10.74,6.273)，α(25.77，-2.236)。

respectively carrying out conjugate multiplication on channel real data corresponding to the two-dimensional uniform linear array to carry out angle domain accumulation, wherein the expression of the angle domain accumulation processing is as follows:

W＝conj(α(θ,φ))*DataK； (3)

where W represents the value accumulated in the angle domain, conj represents the conjugate operation, and DataK represents the channel data of the angle matching array.

Substituting α (10.74, -2.236), α (25.77, 6.273), α (10.74,6.273), α (25.77, -2.236) into formula (3) to obtain:

because two groups of joint angles in the 4 groups of joint angles are correct angle combinations, corresponding to the formula (4), the accumulated values obtained by calculating the correct angle combinations are obviously larger than the wrong angle combinations, and therefore the real angles corresponding to the targets are judged.

The final result is that [10.74, -2.236], [25.77, 6.273] is the result after the angles of the same-distance and same-speed targets are matched, namely [10.74, -2.236] is the azimuth angle and the pitch angle corresponding to one of the targets, and [25.77, 6.273] is the azimuth angle and the pitch angle corresponding to the other target. The three-dimensional position of the target after correct detection is finally obtained as shown in fig. 8. In fig. 8,' indicates the real target position, and the circle indicates the detected target position, so the problem of azimuth angle/pitch angle matching of the targets at the same distance and speed can be successfully solved by the invention.

The target angle measuring device provided by the present invention is described below, and the target angle measuring device described below and the target angle measuring method described above may be referred to in correspondence with each other.

Fig. 9 is a schematic view of a target angle measuring device according to an embodiment of the present invention, as shown in fig. 9. An apparatus 900 for measuring an angle of an object includes an array construction module 910, an estimation module 920, a combination module 930, and a matching module 940. Wherein,

the array construction module 910 is configured to construct an azimuth virtual linear array, a pitch virtual linear array, and an angle matching array including target azimuth information and pitch angle information according to a preset number of transmitting antennas, a preset number of receiving antennas, an azimuth resolution, a preset pitch resolution, an azimuth FOV, and a preset pitch FOV.

An estimating module 920, configured to obtain azimuth channel data, elevation channel data, and angle-matched array channel data from the azimuth virtual linear array, the elevation virtual linear array, and the angle-matched array, and perform azimuth angle estimation and elevation angle estimation based on the azimuth channel data and the elevation channel data, respectively, to obtain an azimuth angle set and an elevation angle set.

And a combining module 930, configured to combine the angle elements in the azimuth angle set and the angle elements in the pitch angle set to obtain at least one group of joint angles.

A matching module 940, configured to perform matching judgment on the at least one group of joint angles based on the angle matching array channel data to obtain an azimuth angle and a pitch angle corresponding to the target.

Illustratively, the array building module 910 is further configured to:

Illustratively, the estimating module 920 is further configured to:

acquiring collected echo data of a frame;

distinguishing data of each channel according to the frame of echo data;

Illustratively, the estimating module 920 is further configured to:

Illustratively, the matching module 940 is further configured to:

α(θ,φ)＝exp(j·2π·(D_Azi·sinθ+D_Ele·sinφ)/λ)；

W＝conj(α(θ,φ))*DataK；

Referring to fig. 10, fig. 10 illustrates a physical structure diagram of an electronic device, where the electronic device may include: a processor (processor)1010, a communication Interface (Communications Interface)1020, a memory (memory)830 and a communication bus 1040, wherein the processor 1010, the communication Interface 1020 and the memory 1030 are in communication with each other via the communication bus 1040. Processor 1010 may invoke logic instructions in memory 1030 to perform any of the target goniometric methods previously described.

Furthermore, the logic instructions in the memory 1030 can be implemented in software functional units and stored in a computer readable storage medium when the logic instructions are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A MIMO radar target angle measurement method is characterized by comprising the following steps:

2. The MIMO radar target angle measurement method of claim 1, wherein the constructing of the azimuth virtual line array, the elevation virtual line array and the angle matching array comprising target azimuth information and elevation information according to the preset number of transmitting antennas, the number of receiving antennas, the azimuth resolution, the elevation resolution, the azimuth FOV and the elevation FOV comprises:

3. The MIMO radar target angle measurement method according to claim 2, wherein the calculating the azimuth virtual line array aperture and the elevation virtual line array aperture according to the preset azimuth resolution and the preset pitch resolution respectively comprises:

4. The MIMO radar target angle measurement method of claim 2, wherein the determining a first array element spacing representing an array element position spacing of the azimuth virtual line array according to the azimuth FOV and a second array element spacing representing an array element position spacing of the pitch virtual line array according to the pitch FOV comprises:

5. The MIMO radar target angle measurement method of claim 1, wherein the obtaining azimuth channel data, elevation channel data, and angle-matching array channel data from the azimuth virtual line array, elevation virtual line array, and angle-matching array comprises:

acquiring collected echo data of a frame;

distinguishing data of each channel according to the frame of echo data;

6. The MIMO radar target angle measurement method of claim 2, wherein the performing azimuth angle estimation and pitch angle estimation based on the azimuth channel data and the pitch channel data, respectively, to obtain an azimuth angle set and a pitch angle set comprises:

7. The MIMO radar target angle measurement method of claim 2, wherein the performing azimuth angle estimation and pitch angle estimation based on the azimuth channel data and the pitch channel data, respectively, to obtain an azimuth angle set and a pitch angle set further comprises:

8. The MIMO radar target angle measurement method of claim 1, wherein the determining the matching of the at least one set of joint angles based on the angle-matching array channel data to obtain azimuth angles and elevation angles corresponding to a target comprises:

9. The MIMO radar target angle measurement method of claim 8, wherein the steering vector expression of the angle matching array is determined by:

α(θ,φ)＝exp(j·2π·(D_Azi·sinθ+D_Ele·sinφ)/λ)；

whereinWhere α (θ, φ) represents a steering vector, θ represents an azimuth angle, φ represents a pitch angle, D_AziIndicating the azimuthal physical separation, D_EleDenotes the physical pitch, λ denotes the wavelength, and j denotes the complex sign of the phase.

10. The MIMO radar target angle measurement method of claim 9, wherein the azimuth physical separation D_AziAnd said physical pitch spacing D_EleRepresented by the formula:

11. The MIMO radar target ranging method of claim 10, wherein the angular domain digital beamforming process is performed according to:

W＝conj(α(θ,φ))*DataK；

12. A MIMO radar target angle measurement apparatus, the apparatus comprising:

13. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program implements the MIMO radar target ranging method of any one of claims 1 to 11.

14. A non-transitory computer readable storage medium having stored thereon a computer program, wherein the computer program, when executed by a processor, implements the MIMO radar target ranging method according to any one of claims 1 to 11.