Radar imaging method and radar imaging device

Abstract

The invention provides a radar imaging method and a radar imaging device, and the method comprises the steps: obtaining a first image of a detection object, processing the first image based on a reference image, and obtaining a deformation data set corresponding to the first image, the deformation data set comprising deformation data corresponding to each pixel point in the first image; further, based on the deformation data set and the first image, a second image corresponding to the detection object is obtained, and the second image is a three-dimensional image. According to the method, in the process of obtaining the three-dimensional image through the radar imaging technology, the number of antenna arrays deployed by the radar is reduced, so that the resource overhead is saved, and the cost is reduced.

Description

Technical Field

[0001] This application relates to the field of radar technology, and in particular, to a radar imaging method and a radar imaging device. Background Art

[0002] Radar imaging technology is a technology that uses electromagnetic wave signals for imaging. It can obtain a radar image corresponding to a detection target by processing the echo signal of the detection target (a signal formed by the detection target reflecting the electromagnetic wave signal transmitted by the radar).

[0003] Differential Interferometric Synthetic Aperture Radar (D-InSAR) technology is a widely used radar imaging technology. Specifically, the D-InSAR technology can obtain multiple radar images of a detection object at different times or different angles based on electromagnetic wave signals transmitted by at least two antenna arrays, and obtain a three-dimensional (3D) high-resolution image of the detection object according to the multiple radar images.

[0004] However, the radar in the D-InSAR technology includes at least a dual antenna array, and the cost is relatively high in scenarios where multiple radars need to be deployed. Therefore, how to reduce the cost of obtaining a 3D high-resolution image remains to be studied. Summary of the Invention

[0005] Embodiments of this application provide a radar imaging method and a radar imaging device, which are beneficial to reducing the cost of obtaining a 3D high-resolution image.

[0006] In a first aspect, this application provides a radar imaging method. Taking a radar that executes this method as an example, the radar includes a single antenna array. The method includes: obtaining a first image of a detection object, and processing the first image based on a reference image to obtain a set of deformation data corresponding to the first image. The set of deformation data includes deformation data corresponding to each pixel point in the first image; further, based on the set of deformation data and the first image, obtaining a second image corresponding to the detection object, where the second image is a three-dimensional image.

[0007] Based on the method described in the first aspect, a three-dimensional image of a detection object can be obtained by deploying a radar with a single antenna array and a reference image. Compared with the method of obtaining a three-dimensional image of a detection object by deploying a radar with multiple antenna arrays, it is beneficial to reduce the number of antenna arrays deployed by the radar, thereby saving resource (such as the transmission resource of electromagnetic wave signals, etc.) overhead during the process of obtaining a three-dimensional image, and being beneficial to reducing the cost of obtaining a three-dimensional high-resolution image.

[0008] In a possible implementation, the reference image is the image corresponding to the reference region. The detection object includes multiple regions, and the size of each region in the multiple regions is less than or equal to the size of the reference region. The first image is the image corresponding to any one of the multiple regions. By implementing this possible implementation, when the sizes of the multiple regions corresponding to the detection object are the same (or understood as the texture of the detection object being uniform), the images of each region can be processed using the same reference image, which helps reduce the computational complexity.

[0009] In a possible implementation, interference processing is performed on the first image based on the reference image to obtain a first interference fringe pattern. The first interference fringe pattern includes the first phase differences corresponding to each pixel point in the first image. The first pixel point is any pixel point in the first image, and the first phase difference corresponding to the first pixel point is the difference between the phase of the first pixel point and the phase of the first reference pixel point. The first reference pixel point is the pixel point in the reference image corresponding to the first pixel point. Further, based on the first phase differences corresponding to each pixel point in the first image, a set of deformation data corresponding to the first image is obtained.

[0010] In a possible implementation, a first reference quantity is obtained. The first reference quantity is used to indicate the displacement data corresponding to the pixel points in the first image. Further, based on the first phase differences corresponding to each pixel point in the first image and the first reference quantity, a set of deformation data corresponding to the first image is obtained. By implementing this possible implementation, the displacement data can be understood as the overall movement data of the detection object. Determining the set of deformation data based on the first reference quantity indicating the displacement data and the first phase differences corresponding to each pixel point helps reduce the influence of the displacement data on the deformation data of each pixel point, thereby helping to improve the quality of the first image.

[0011] In a possible implementation, the first reference quantity is a phase reference quantity. In this case, based on the phase reference quantity and the first phase differences corresponding to each pixel point in the first image, a second interference fringe pattern is obtained. The second interference fringe pattern includes the second phase differences corresponding to each pixel point in the first image. The second phase difference corresponding to the first pixel point is the difference between the first phase difference corresponding to the first pixel point and the phase reference quantity. Further, based on the second phase differences corresponding to each pixel point in the first image, a set of deformation data corresponding to the first image is obtained. By implementing this possible implementation, the deformation data of each pixel point can be determined through the phase differences of each pixel point after removing the phase reference quantity, which helps reduce the influence of the displacement data on the deformation data of each pixel point and helps improve the imaging quality of the first image.

[0012] In a possible implementation, the first reference quantity is displacement data. In this case, based on the first phase difference included in the first interference pattern, a set of surface data corresponding to the first image is obtained, and the set of surface data includes the surface data corresponding to each pixel point in the first image. Further, based on the set of surface data and the displacement data, a set of deformation data corresponding to the first image is obtained, and the deformation data in the set of deformation data is the difference between the surface data in the set of surface data and the displacement data. By implementing this possible implementation, after obtaining the surface data of each pixel point, the displacement data can be removed from the surface data to obtain the deformation data of each pixel point, which is beneficial to reducing the influence of the displacement data on the deformation data of each pixel point and improving the imaging quality of the first image.

[0013] In a possible implementation, the first image is interfered with based on a reference image to obtain a third interference pattern. Further, the third interference pattern is subjected to phase unwrapping processing to obtain the first interference pattern. By implementing this possible implementation, it is beneficial to weaken the noise and retain the true phase difference, thereby improving the imaging quality of the first image.

[0014] In a possible implementation, the transmitting crosstalk signal matrix corresponding to the radar is obtained, and the radar echo signal matrix reflected by the detection object is obtained. Further, based on the radar echo signal matrix and the transmitting crosstalk signal matrix, the first image is obtained. By implementing this possible implementation, when the distance between the radar and the detection object is approximately equal to the distance between the transmitting and receiving antennas of the radar, the interference of the direct echo (i.e., the echo formed when the electromagnetic wave emitted by the radar transmitting antenna is directly received by the receiving antenna) on imaging can be weakened, which is beneficial to improving the imaging quality of the first image.

[0015] In a possible implementation, a single antenna array of the radar includes M transmitting antennas and N receiving antennas, and the radar corresponds to M×N antenna array elements (or virtual antenna array elements). By implementing this possible implementation, an antenna array including M×N antenna array elements can be constructed by M+N physical antennas, and the effect of constructing more virtual array elements with a small number of transceiver channels can be achieved, which is beneficial to cost savings.

[0016] Second aspect, the present application provides a radar imaging device, which may be a radar, a device in the radar, or a device that can be used in combination with the radar. Among them, the radar imaging device may also be a chip system. The radar imaging device can execute the method described in the first aspect. The functions of the radar imaging device can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module may be software and / or hardware. The operations and beneficial effects performed by the radar imaging device can refer to the method and beneficial effects described in the first aspect above.

[0017] Third aspect, the present application provides a radar imaging device, including: a processor and a memory; the memory is used to store one or more programs, and the one or more programs include computer execution instructions. When the device runs, the processor executes the one or more programs stored in the memory to enable the device to execute the method described in the first aspect.

[0018] Fourth aspect, the present application provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed by a radar imaging device, the method described in the first aspect is implemented.

[0019] Fifth aspect, the present application provides a computer program product including instructions. When a radar imaging device reads and executes the instructions, the radar imaging device is enabled to execute the method described in the first aspect. Description of the Drawings

[0020] Figure 1 is a schematic diagram of an application scenario provided by an embodiment of the present application;

[0021] Figure 2 is a schematic diagram of a radar imaging method provided by an embodiment of the present application;

[0022] Figure 3 is a schematic flowchart of another application scenario provided by an embodiment of the present application;

[0023] Figure 4 is a schematic diagram of an antenna array of a radar provided by an embodiment of the present application;

[0024] Figure 5 is a schematic diagram of a radar imaging process provided by an embodiment of the present application;

[0025] Figure 6 is a schematic diagram of the structure of a radar imaging device provided by an embodiment of the present application;

[0026] Figure 7 is a schematic diagram of the structure of another radar imaging device provided by an embodiment of the present application. Detailed implementation manners

[0027] For the convenience of understanding the relevant content of the embodiments of the present application, some terms involved in the embodiments of the present application are further explained below. This part is only for convenience of understanding and cannot be regarded as a disclosure or specific limitation of the technical solution of the present application.

[0028] 1. Radar imaging technology

[0029] Radar imaging technology is a technology that uses electromagnetic wave signals for imaging. The process of radar imaging is generally as follows: The radar emits electromagnetic wave signals to the detection object; receives the echo signals formed by the detection object reflecting the electromagnetic wave signals; and obtains a radar image based on the echo signals.

[0030] Generally, the resolution of a radar image is related to the aperture of the radar antenna, or it can be understood that the resolution of the radar image is related to the width of the radar beam. The larger the aperture of the radar antenna, the narrower the radar beam obtained, and the higher the resolution of the radar image obtained.

[0031] It should be noted that the radar mentioned in the present application can also be referred to as a radar device, a detector, a radar detection device, a detection device, or a radar signal transmitting device. It should be understood that the radar in the embodiments of the present application can be a vehicle-mounted radar, an airborne radar, a spaceborne radar, a shipborne radar, a missile-borne radar, a ground-based radar, a radar station, etc.

[0032] It should also be noted that the electromagnetic wave signals emitted by the radar in the present application include but are not limited to millimeter waves, and can also be applicable to other frequency bands, such as the microwave band, the terahertz band, and can even be extended to other electromagnetic waves (including light waves, such as infrared, etc.) frequency bands. The present application does not limit the attributes of the electromagnetic wave signals emitted by the radar.

[0033] 2. Synthetic aperture radar (SAR)

[0034] SAR imaging technology is a technology that forms high-resolution radar imaging by using the relative motion between the radar and the detection object. Specifically, during the relative motion between the radar and the detection object, the radar emits multiple electromagnetic wave signals to the detection object and receives multiple echo signals reflected by the detection object; further, the multiple echo signals are synthesized to obtain an echo signal of an analog (or understood as a virtual) large-aperture antenna, and a radar image is obtained based on the echo signal of the analog large-aperture antenna.

[0035] 3. Multiple-input multiple-output (MIMO) radar

[0036] MIMO radar technology is a new type of radar system that combines MIMO technology with digital array technology in the radar field. Generally, this radar consists of multiple transmitting antennas and multiple receiving antennas (the antennas can also be used for both transmitting and receiving). Each transmitting antenna emits different signal waveforms. After the transmitted signals are reflected by the target, they are received by multiple receiving antennas and then sent to the signal processing unit through multiple receivers for subsequent processing.

[0037] 4. Interferometric Synthetic Aperture Radar (InSAR)

[0038] InSAR technology can be regarded as an extension of SAR technology. Through InSAR technology, a three-dimensional image of the detected object can be formed, which is usually used in fields such as digital elevation model establishment and crustal deformation detection. Specifically, the working principle of InSAR technology is to use two antennas to observe simultaneously (such as the single-track dual-antenna mode) to obtain a pair of SAR images of the same target area. By obtaining the phase difference between the two SAR images corresponding to the same target area and combining the orbital data (such as the relative position between the two antennas), high-precision and high-resolution ground elevation information can be obtained, thereby obtaining information such as the terrain and landform of the target area.

[0039] 5. D-InSAR

[0040] D-InSAR technology can be considered as an extension of InSAR technology, which can sense the minute deformation of the target area. Specifically, D-InSAR technology can, based on the electromagnetic wave signals transmitted by at least two antenna arrays, obtain multiple radar images of the detected object at different times, and perform interference processing on the two radar images at different times to obtain an interferogram; further, based on the phase value of the interferogram, the path difference of the microwave in the two imaging processes can be obtained, and the minute change of the target area can be calculated based on this path difference.

[0041] 6. Interference Phase Processing

[0042] Interference phase processing is a signal processing technology, also known as interference processing in this application, which is widely used in fields such as radar signal processing, optical signal processing, or communication signal processing. Interference phase processing uses the phase information of the signal to analyze, enhance, and denoise the signal.

[0043] Interference processing can be achieved through methods such as the phase difference method, phase demodulation method, phase stitching method, and phase coding method. The interference processing mentioned in this application includes, but is not limited to, one or a combination of several of these methods.

[0044] 7. Phase Unwrapping Processing

[0045] In the phase usually measured (which can also be understood as the wrapped phase), in addition to the phase of interest to people (or understood as the true phase), there are also some other phases (i.e., noise). By performing phase unwrapping on the measured phase, the noise in this phase can be removed while retaining the true phase. Phase unwrapping is widely used in applications such as InSAR and optical interferometry.

[0046] Phase unwrapping can be achieved by methods such as the branch cut method, the unweighted least squares method, the minimum cost flow method, etc. The phase unwrapping mentioned in this application includes, but is not limited to, the combination of one or more of these methods.

[0047] To facilitate the specific understanding of the embodiments of this application, the application scenarios involved in the embodiments of this application will be exemplarily described below. It should be noted that the system architecture and application scenarios described in this application are for more clearly explaining the technical solutions of this application and do not constitute a limitation on the technical solutions provided by this application. It should be understood that with the evolution of the system architecture and the emergence of new business scenarios, the technical solutions provided by this application are equally applicable to similar technical problems.

[0048] As Figure 1 shown, Figure 1 is a schematic diagram of an application scenario of an embodiment of this application. This application scenario includes a radar and a detection object. In this application scenario, the detection object and the radar meet one or more of the following conditions: ① The distance between the detection object and the radar is fixed; ② The detection object is of uniform texture, that is, it can be understood that the detection object is divided into multiple regions according to a fixed area (for example, the range of one radar imaging), and each region is almost the same or similar; ③ There is relative motion between the radar and the detection object. For example, relative to the detection object, the radar has a relative motion to the right; that is, relative to the radar, the detection object has a relative motion to the left; ④ During the process of relative motion between the radar and the detection object, the radar sends electromagnetic wave signals multiple times and receives the echo signals of the detection object multiple times.

[0049] The radar provided by the embodiments of this application may include a transmitting antenna, a receiving antenna, a signal processing unit, etc., where:

[0050] (1) The transmitting antenna is used to transmit at least one electromagnetic wave signal. The electromagnetic wave signal can be, for example, a frequency modulated continuous wave (FMCW), a continuous wave (CW), a phase modulation continuous wave (PMCW), or an orthogonal frequency division multiplexing (OFDM), etc.

[0051] Among them, the number of transmitting antennas can be one or more. It should be understood that the more the number of transmitting antennas, the larger the antenna aperture of the radar and the higher the angular resolution.

[0052] (2) The receiving antenna is used to receive at least one echo signal reflected by the target object from at least one first signal.

[0053] Among them, the number of receiving antennas can be one or more. It should be understood that the more the number of receiving antennas, the larger the antenna aperture of the radar and the higher the angular resolution.

[0054] (3) The signal processing unit is used to image the target object.

[0055] To save the cost of obtaining a 3D high-resolution image by radar, the present application provides a radar imaging method and a radar imaging device. The radar imaging method and the radar imaging device provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0056] Please refer to Figure 2 , Figure 2 which is a schematic flowchart of a radar imaging method provided by an embodiment of the present application. As Figure 2 shown, the radar imaging method includes the following steps S201 to step S203. Figure 2 The method execution subject shown is described by taking a radar as an example. It can be understood that Figure 2 the method execution subject shown can also be a module (for example, a chip) in the radar, or a device used in combination with the radar. Among them:

[0057] S201. Obtain a first image of the detection object.

[0058] It should be noted that the first image may be an image corresponding to the entire area of the detection object, or an image corresponding to a partial area of the detection object. This application does not make specific limitations in this regard. For the convenience of understanding the solution, hereinafter, only the case where the first image is an image corresponding to a partial area (denoted as the target area) of the detection object is taken as an example for description. Moreover, when the first image is an image corresponding to the target area of the detection object, the detection object may include multiple regions of the same size, and the target area is one of the multiple regions. Through the solution provided by this application, images of different regions of the detection object can be obtained at different times respectively. This application only takes obtaining the first image of the target area of the detection object as an example for exemplary description.

[0059] That is to say, the radar emits an electromagnetic wave signal to the target area of the detection object and receives the echo signal formed by reflecting the electromagnetic wave signal from the target area of the detection object. Further, the radar obtains the first image according to the echo signal.

[0060] Exemplarily, as Figure 3 shown, take the scenario of detecting whether the belt for transporting goods is damaged by the radar imaging method provided by this application as an example. In Figure 3 , the detection object is the belt for transporting goods; the radar is a fixed radar deployed below the belt; the radar has a relative movement to the right with respect to the belt. In this scenario, the area of the region imaged by the radar once is denoted as S. The radar emits an electromagnetic wave signal to the target area corresponding to the detection object (i.e., the detection area with an area of S) and receives the echo signal matrix reflected from the target area. Further, the radar obtains the first image corresponding to the target area of the detection object according to the echo signal matrix. It should be noted that this application does not make specific limitations on the deployment position of the radar in Figure 3 . For example, the radar can also be deployed between two belts.

[0061] It should be noted that the radar in this application is a radar deployed with a single antenna array. The size of the target area corresponding to the first image mentioned in this application is the range that can be covered by the radar beam of the antenna array. Usually, multiple antenna elements corresponding to the same processing unit (or called a processor, a processing module, etc.) are called an antenna array. That is to say, the echo signals received by the multiple antenna elements in the antenna array are processed by the same processing unit.

[0062] It should also be noted that the antenna array mentioned in this application may be composed of real antenna elements (i.e., physical antennas). For example, a two-dimensional antenna array includes L×K antenna elements, then this antenna array includes L×K physical antennas. The antenna array mentioned in this application may also be composed of virtual antenna elements. For example, an antenna array is composed of L antenna elements to form a linear array, and L×K virtual antenna elements are formed by collecting data at K moments. Further, the antenna array including L antenna elements may also be formed in the way of virtual antenna elements. For example, a linear array antenna with the number of array elements L = M×N, then this antenna array may only include M + N physical antennas. That is to say, in a possible implementation manner, a single antenna array for radar deployment in this application may include M transmitting antennas and N receiving antennas (for example, as Figure 4 shown). In this case, this radar corresponds to M×N virtual antenna elements. It can be understood that after the radar sends an electromagnetic wave signal through 1 transmitting antenna, 1 receiving antenna can be selected from N receiving antennas to receive the echo signal. Through different combinations of transmitting and receiving antennas, a row of radar echo signals with a size of L = M×N can be obtained. Considering the relative motion between the radar and the target object, after collecting data for K consecutive time periods, a radar echo signal matrix with a size of L×K can be obtained. It should be understood that according to the relative motion speed v between this radar and the target object, the pulse repetition interval (PRI) of the radar, and the width w covered by the antenna array of the radar, the imaging area S corresponding to this radar echo matrix can be obtained as S = v×K×PRI. Further, a first image is obtained based on this radar echo signal matrix.

[0063] It should also be noted that the area S of the area imaged by the radar at one time in this application can be understood as the range of the detection object that the antenna array of this radar can cover. In a possible implementation manner, the conditions for the SAR imaging technology can be constructed through the relative motion between the antenna array of the radar and the detection object, and the target area of the detection object can be imaged through the SAR imaging technology. As Figure 5 shown, the antenna elements corresponding to the antenna array of this radar are a linear array (taking the linear array in Figure 5 5a including M×N antenna elements as an example); through the relative motion between this linear array and the detection object, and by collecting data of K PRIs using the relative motion between the antenna array of the radar and the detection object, a virtual equivalent two-dimensional planar array can be formed (as Figure 5As shown in Figure 5b, the size of the virtual planar array is M×N×K). According to the echo signals received on each antenna element in the virtual equivalent two-dimensional planar array, a first image corresponding to the target area is generated. Optionally, in order to avoid the interference of grating lobes on imaging, the interval between two adjacent antenna elements can be no more than one-quarter wavelength.

[0064] In a possible application scenario, when the distance between the radar and the detection object is relatively close (for example, the distance between the radar and the detection object is similar to the distance between the receiving antenna and the transmitting antenna on the radar), there is a situation where the signal transmitted by the transmitting antenna of the radar is received by the receiving antenna, generating a direct echo. This direct echo will interfere with the imaging result. In order to avoid the interference of the direct echo on imaging, the present application also provides a possible implementation manner.

[0065] In this possible implementation manner, a transmitting crosstalk signal matrix corresponding to the radar is obtained, and a radar echo signal matrix reflected by the detection object is obtained; further, based on the radar echo signal matrix and the transmitting crosstalk signal matrix, a first image is obtained. That is to say, after obtaining the radar echo signal matrix reflected by the detection object, the radar echo signal matrix is processed based on the transmitting crosstalk signal matrix corresponding to the radar to obtain a first image.

[0066] Exemplarily, the radar can collect an echo signal matrix (i.e., the transmitting crosstalk signal matrix) in the absence of a detection object and store the transmitting crosstalk signal matrix. Subsequently, during the imaging process of the detection object, after the radar obtains the radar echo signal matrix reflected by the detection object, the radar echo signal matrix is subtracted from the transmitting crosstalk signal matrix, and the interference of the transmitting crosstalk signal matrix can be cancelled to obtain a radar echo signal matrix after interference cancellation. Further, imaging is performed based on the radar echo signal matrix after interference cancellation to obtain a first image.

[0067] S202. Process the first image based on the reference image to obtain deformation data corresponding to the first image. Wherein, the deformation data includes the deformation data corresponding to each pixel point in the first image.

[0068] Among them, the reference image is the image corresponding to the reference area, which can be understood as the target area under the condition of no deformation (or understood as a reference area approximate to the target area). That is to say, the size of the reference area is greater than or equal to the size of the target area. It can be understood that when the size of the reference area is equal to the size of the target area, the pixel points in the reference image (hereinafter referred to as reference pixel points) correspond one-to-one with the pixel points in the first image; when the size of the reference area is greater than the size of the target area, the reference image includes reference pixel points corresponding to the pixel points in the first image. It should be noted that in this application, the radar can obtain the reference image by detecting the target area (or reference area) under the condition of no deformation, or can obtain the reference image from its own storage space (or the storage space in communication connection with the radar). This application does not specifically limit the way for the radar to obtain the reference image.

[0069] That is to say, after obtaining the first image, based on the reference image and the first image, determine the deformation data generated by the deformation of the target area relative to the reference area.

[0070] In a possible implementation manner of S202, perform interference processing on the first image based on the reference image to obtain a first interference fringe pattern, and the first interference fringe pattern includes the first phase difference corresponding to each pixel point in the first image; further, based on the first phase difference corresponding to each pixel point in the first image, obtain a deformation data set corresponding to the first image, and the deformation data set includes the deformation data corresponding to each pixel point in the first image. Taking the first phase difference corresponding to any pixel point (for example, the first pixel point) in the first image as an example, the first phase difference corresponding to the first pixel point included in the first interference fringe pattern is the difference between the phase of the first pixel point and the phase of the first reference pixel point (the reference pixel point in the reference image corresponding to the first pixel point).

[0071] In a possibility, the first phase difference φ corresponding to a certain pixel point in the first image and the deformation data ΔR d ′ of this pixel point satisfy the condition shown in formula (1).

[0072]

[0073] Among them, λ is the wavelength of the electromagnetic wave emitted by the antenna array of the radar.

[0074] It can be understood that, in addition to the deformation data generated due to the deformation of the detection object in the target area, the first phase differences of the respective pixel points included in the first interference fringe pattern also include displacement data (or understood as the overall movement data corresponding to the detection target, such as overall lifting or overall lowering) generated under the influence of some external factors (or understood as noise, such as the jitter of the detection object). In this case, a first reference quantity can be obtained, and this first reference quantity is used to indicate the displacement data corresponding to the pixel points in the first image; further, based on the first phase differences corresponding to the respective pixel points in the first image and this first reference quantity, a deformation data set corresponding to the first image is obtained. Through such an implementation manner, it is beneficial to reduce the influence of the external factors on the deformation data and beneficial to improving the imaging quality of the generated first image.

[0075] It should be noted that this first reference quantity can be a preset empirical value tested according to experimental data, and this first reference quantity can also be a value determined according to the phases of the respective pixel points in the first image. This application does not specifically limit the value of this first reference quantity and the manner of obtaining this first reference quantity.

[0076] For ease of understanding, the following takes the first reference quantity as the phase reference quantity or displacement data as an example to provide a possible implementation manner for obtaining the first reference quantity. In this implementation manner, from the multiple first phase differences included in the first interference fringe pattern, the first phase differences with larger values are removed (for example, the first phase difference with the largest value is removed, or the phase differences greater than the first threshold are removed); based on the remaining first phase differences included in the first interference fringe pattern, the average value of the phase differences is fitted. Further, this average phase value (i.e., the phase reference quantity) can be used as the first reference quantity; or, displacement data can also be obtained based on this average phase value, and this displacement data can be used as the first reference quantity. Among them, this displacement data and the phase reference quantity can also meet the conditions shown in the foregoing formula (1), that is, regarding the phase reference quantity as φ in formula (1) and regarding this displacement data as ΔR d ′. The following explains how to obtain the deformation data of each pixel point in the first image in the case where the first reference quantity is the phase reference quantity and the displacement data respectively through the following two situations.

[0077] Situation 1: The first reference quantity is the phase reference quantity

[0078] In this case, based on this phase reference quantity and the first phase differences corresponding to the respective pixel points in the first image, a second interference fringe pattern including the second phase differences corresponding to the respective pixel points in the first image can be obtained, and the second phase difference corresponding to the first pixel point is the difference between the first phase difference corresponding to the first pixel point and the phase reference quantity. Further, based on the second phase differences corresponding to the respective pixel points in the first image, a deformation data set corresponding to the first image is obtained.

[0079] That is to say, after obtaining the first phase difference corresponding to each pixel point in the first image, the difference between the first phase difference corresponding to each pixel point and the phase reference quantity is the second phase difference corresponding to each pixel point. The second interference fringe pattern includes the second phase difference corresponding to all pixel points in the first image. Further, based on the second phase difference corresponding to each pixel point in the first image, a deformation data set corresponding to the first image is obtained. Among them, the second phase difference corresponding to the first pixel point and the deformation data corresponding to the first pixel point can also satisfy the conditions shown in the foregoing formula (1), that is, regarding the second phase difference corresponding to the first pixel point as φ in formula (1), and regarding the deformation data corresponding to the first pixel point as ΔR in formula (1). d ′.

[0080] Case 2: The first reference quantity is displacement data

[0081] In this case, based on the first phase difference included in the first interference fringe pattern, a surface data set corresponding to the first image can be obtained, and the surface data set includes the surface data corresponding to each pixel point in the first image; further, based on the surface data set and the displacement data, a deformation data set corresponding to the first image is obtained, and the deformation data in the deformation data set is the difference between the surface data in the surface data set and the displacement data.

[0082] That is to say, according to the first phase difference φ of each pixel point in the first image and the foregoing formula (1), the surface data of each pixel point (that is, ΔR in the formula (1)) d ′) is obtained. The surface data of each pixel point includes the deformation data and displacement data corresponding to the pixel point; in this case, the deformation data of any pixel point is the difference between the surface data of the pixel point and the displacement data.

[0083] It can be understood that the phase differences obtained by the above method (including the foregoing first phase difference or the foregoing second phase difference) may include some other phases (i.e., noise) in addition to the true phase difference (i.e., the phase difference corresponding to the true deformation data). In this case, through phase unwrapping processing, the true phase difference of each pixel point in the first image can be obtained. It should be noted that the specific execution order of this phase unwrapping processing in this application is not specifically limited.

[0084] In a possible implementation, the steps of the phase unwrapping process are included in the process of obtaining the first interference pattern. That is, the radar performs interference processing on the first image based on the reference image to obtain a third interference pattern. The third interference pattern includes the third phase difference corresponding to each pixel point in the first image. The third phase difference includes the first phase difference and noise other than the first phase difference. Further, the third interference pattern is subjected to phase unwrapping processing to obtain the first interference pattern.

[0085] In another possible implementation, the steps of the phase unwrapping process are included in the process of obtaining the second interference pattern. That is, after the radar performs interference processing on the first image based on the reference image to obtain the first interference pattern, a fourth interference pattern is obtained according to the first interference pattern and the phase reference quantity. The fourth interference pattern includes the fourth phase difference corresponding to each pixel point in the first image. The fourth phase difference includes the second phase difference and noise other than the second phase difference. Further, the fourth interference pattern is subjected to phase unwrapping processing to obtain the aforementioned second interference pattern. Among them, the process of obtaining the fourth interference pattern according to the first interference pattern and the phase reference quantity can refer to the description of the process of obtaining the second interference pattern according to the first interference pattern and the phase reference quantity as described above, and will not be elaborated here.

[0086] S203. Based on the deformation data set and the first image, obtain a second image corresponding to the detection object, and the second image is a three-dimensional image.

[0087] Superimpose the deformation data of each pixel point in the first image on the first image to obtain a three-dimensional image corresponding to the target area of the detection, that is, the second image.

[0088] Optionally, in addition to including the deformation data (or understood as surface undulation data) of each pixel point, the second image may further include the intensity data of the echo signal corresponding to each pixel point. Exemplarily, the intensity data corresponding to each pixel point in the second image may also be presented in the form of a heat map corresponding to the second image.

[0089] In summary, by deploying a radar with a single antenna array and a reference image, a three-dimensional image of the detection object can be obtained. Compared with the method of obtaining a three-dimensional image of the detection object by deploying a radar with a multi-antenna array, it is beneficial to reduce the number of antenna arrays deployed by the radar, thereby facilitating resource savings in the process of obtaining a three-dimensional image of the detection object and reducing the cost of obtaining a three-dimensional image.

[0090] It is understandable that in order to realize the functions in the above-mentioned embodiments, the radar includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software transceiver components driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0091] Figure 6 and Figure 7 A schematic diagram of the structure of a possible radar imaging device provided for an embodiment of the present application. These radar imaging devices can be used to implement the functions of the radar in the above method embodiments, and thus can also achieve the beneficial effects possessed by the above method embodiments. In an embodiment of the present application, the radar imaging device can be a radar, or a module (such as a chip) applied to a radar, or a device having a communication connection with the radar, or a module (such as a chip) deployed in a device having a communication connection with the radar.

[0092] like Figure 6 As shown, the radar imaging device 600 includes a processing unit 610 and a transceiver unit 620. The radar imaging device 600 is used to implement the above Figure 2 When the radar imaging device 600 is used to implement Figure 2 The functions of the radar in the method embodiment shown are: a transceiver unit 620, used to obtain a first image of the detected object; a processing unit 610, used to process the first image based on a reference image to obtain a deformation data set corresponding to the first image, wherein the deformation data set includes deformation data corresponding to each pixel in the first image; the processing unit 610 is also used to obtain a second image corresponding to the detected object based on the deformation data set and the first image, wherein the second image is a three-dimensional image.

[0093] In a possible implementation, the reference image is an image corresponding to the reference area, the detection object includes multiple areas, the size of each area in the multiple areas is smaller than or equal to the size of the reference area, and the first image is an image corresponding to any one of the multiple areas.

[0094] In a possible implementation, the processing unit 610 is further configured to perform interference processing on the first image based on the reference image to obtain a first interference fringe pattern, where the first interference fringe pattern includes a first phase difference corresponding to each pixel point in the first image. The first pixel point is any pixel point in the first image, and the first phase difference corresponding to the first pixel point is the difference between the phase of the first pixel point and the phase of the first reference pixel point. The first reference pixel point is the pixel point in the reference image corresponding to the first pixel point; the processing unit 610 is further configured to obtain a deformation data set corresponding to the first image based on the first phase differences corresponding to the pixel points in the first image.

[0095] In a possible implementation, the transceiver unit 620 is further configured to obtain a first reference quantity, where the first reference quantity is used to indicate displacement data corresponding to pixel points in the first image; the processing unit 610 is further configured to obtain a deformation data set corresponding to the first image based on the first phase differences corresponding to the pixel points in the first image and the first reference quantity.

[0096] In a possible implementation, the first reference quantity is a phase reference quantity. The processing unit 610 is further configured to obtain a second interference fringe pattern based on the phase reference quantity and the first phase differences corresponding to the pixel points in the first image. The second interference fringe pattern includes a second phase difference corresponding to each pixel point in the first image. The second phase difference corresponding to the first pixel point is the difference between the first phase difference corresponding to the first pixel point and the phase reference quantity; the processing unit 610 is further configured to obtain a deformation data set corresponding to the first image based on the second phase differences corresponding to the pixel points in the first image.

[0097] In a possible implementation, the first reference quantity is displacement data. The processing unit 610 is further configured to obtain a surface data set corresponding to the first image based on the first phase differences included in the first interference fringe pattern. The surface data set includes surface data corresponding to each pixel point in the first image; the processing unit 610 is further configured to obtain a deformation data set corresponding to the first image based on the surface data set and the displacement data. The deformation data in the deformation data set is the difference between the surface data in the surface data set and the displacement data.

[0098] In a possible implementation, the processing unit 610 is further configured to perform interference processing on the first image based on the reference image to obtain a third interference fringe pattern; the processing unit 610 is further configured to perform phase unwrapping processing on the third interference fringe pattern to obtain the first interference fringe pattern.

[0099] In a possible implementation, the transceiver unit 620 is further configured to obtain a transmitting-end crosstalk signal matrix corresponding to the radar and obtain a radar echo signal matrix reflected by the detection object; the processing unit 610 is further configured to obtain a first image based on the radar echo signal matrix and the transmitting-end crosstalk signal matrix.

[0100] In a possible implementation, a single antenna array of the radar includes M transmitting antennas and N receiving antennas, and the radar corresponds to M×N virtual antenna elements.

[0101] For a more detailed description of the above transceiver unit 620 and processing unit 610, reference may be made to Figure 2 the relevant description of the radar in the illustrated method embodiment.

[0102] As Figure 7 shown, the radar imaging device 700 includes a processor 710 and an interface circuit 720. The processor 710 and the interface circuit 720 are coupled to each other. It can be understood that the interface circuit 720 can be a transceiver or an input / output interface. Optionally, the radar imaging device 700 may further include a memory 730 for storing instructions executed by the processor 710 or storing input data required for the processor 710 to run instructions or storing data generated after the processor 710 runs instructions.

[0103] When the radar imaging device 700 is used to implement Figure 2 the method shown, the processor 710 is used to implement the functions of the above processing unit 610, and the interface circuit 720 is used to implement the functions of the above transceiver unit 620.

[0104] When the above radar imaging device is a chip applied to a radar, the radar chip implements the functions of the radar in the above method embodiment. The radar chip receives an echo signal matrix reflected from a detection object. It can be understood that the echo signal matrix is first received by other modules (such as a radio frequency module or an antenna) in the radar, and then sent by these modules to the radar chip. The radar chip sends an electromagnetic wave signal to the detection object. It can be understood that the electromagnetic wave signal is first sent to other modules (such as a radio frequency module or an antenna) in the radar, and then sent by these modules to the detection object.

[0105] It can be understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0106] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions executable by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a removable hard disk, a CD-ROM, or any other form of storage medium well-known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. The storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC. Additionally, the ASIC can be located in a radar. The processor and the storage medium can also exist as discrete components in the radar.

[0107] The embodiments of the present application also provide a computer program product. The computer program product includes a computer program. When the computer program runs on a computer, it causes the computer to execute the method described in any one of the embodiments as Figure 2 shown.

[0108] The embodiments of the present application also provide a computer storage medium. A computer program is stored on the computer storage medium. When the computer program runs on a computer, it causes the computer to execute the method described in any one of the embodiments as Figure 2 shown.

[0109] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions of the embodiments of the present application are executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable devices. The computer program or instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer program or instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired or wireless manner. The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server or data center integrating one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; it can also be an optical medium, such as a digital video disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile types of storage media.

[0110] In various embodiments of the present application, without special instructions and logical conflicts, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0111] In the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. In the written description of the present application, the character " / " generally represents an "or" relationship between the associated objects before and after; in the formulas of the present application, the character " / " represents a "division" relationship between the associated objects before and after. "Including at least one of A, B, and C" can represent: including A; including B; including C; including A and B; including A and C; including B and C; including A, B, and C.

[0112] It can be understood that the various numerical numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The magnitudes of the serial numbers of the above processes do not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic.

Claims

1. A radar imaging method, characterized in that, the method is applied to a radar, the radar includes a single antenna array, and the method includes: acquiring a first image of a detection object; processing the first image based on a reference image to obtain a set of deformation data corresponding to the first image, the set of deformation data including deformation data corresponding to each pixel point in the first image; obtaining a second image corresponding to the detection object based on the set of deformation data and the first image, the second image being a three-dimensional image.

2. The method according to claim 1, characterized in that, the reference image is an image corresponding to a reference area, the detection object includes a plurality of areas, the size of each area in the plurality of areas is less than or equal to the size of the reference area, and the first image is an image corresponding to any one of the plurality of areas.

3. The method according to claim 1 or 2, characterized in that, the processing the first image based on the reference image to obtain a set of deformation data corresponding to the first image includes: performing interference processing on the first image based on the reference image to obtain a first interference fringe pattern, the first interference fringe pattern including a first phase difference corresponding to each pixel point in the first image, the first pixel point being any pixel point in the first image, the first phase difference corresponding to the first pixel point being the difference between the phase of the first pixel point and the phase of a first reference pixel point, and the first reference pixel point being the pixel point corresponding to the first pixel point in the reference image; obtaining a set of deformation data corresponding to the first image based on the first phase differences corresponding to the pixel points in the first image.

4. The method according to any one of claims 1-3, characterized in that, the method further includes: acquiring a first reference quantity, the first reference quantity being used to indicate displacement data corresponding to pixel points in the first image; the obtaining a set of deformation data corresponding to the first image based on the first phase differences corresponding to the pixel points in the first image includes: obtaining a set of deformation data corresponding to the first image based on the first phase differences corresponding to the pixel points in the first image and the first reference quantity.

5. The method according to claim 4, characterized in that, the first reference quantity is a phase reference quantity, and the obtaining a set of deformation data corresponding to the first image based on the first phase differences corresponding to the pixel points in the first image and the first reference quantity includes: obtaining a second interference fringe pattern based on the phase reference quantity and the first phase differences corresponding to the pixel points in the first image, the second interference fringe pattern including a second phase difference corresponding to each pixel point in the first image, the second phase difference corresponding to the first pixel point being the difference between the first phase difference corresponding to the first pixel point and the phase reference quantity; obtaining a set of deformation data corresponding to the first image based on the second phase differences corresponding to the pixel points in the first image.

6. The method according to claim 4, characterized in that, The first reference quantity is displacement data, and obtaining the deformation data set corresponding to the first image based on the first phase differences corresponding to the respective pixel points in the first image and the first reference quantity includes: Obtaining the surface data set corresponding to the first image based on the first phase differences included in the first interference fringe pattern, where the surface data set includes the surface data corresponding to the respective pixel points in the first image; Obtaining the deformation data set corresponding to the first image based on the surface data set and the displacement data, where the deformation data in the deformation data set is the difference between the surface data in the surface data set and the displacement data.

7. The method according to any one of claims 3-6, wherein, The performing interference processing on the first image based on the reference image to obtain a first interference fringe pattern includes: Performing interference processing on the first image based on the reference image to obtain a third interference fringe pattern; Performing phase unwrapping processing on the third interference fringe pattern to obtain the first interference fringe pattern.

8. The method according to any one of claims 1-7, wherein, The obtaining the first image of the detection object by radar includes: Obtaining the transmitting crosstalk signal matrix corresponding to the radar; Obtaining the radar echo signal matrix reflected by the detection object through the radar; Obtaining the first image based on the radar echo signal matrix and the transmitting crosstalk signal matrix.

9. The method according to any one of claims 1-8, wherein, A single antenna array of the radar includes M transmitting antennas and N receiving antennas, and the radar corresponds to M×N antenna elements.

10. A radar imaging device, wherein, It includes a module for executing the method according to any one of claims 1-9.

11. A radar imaging device, wherein, The radar imaging device includes a transmitting antenna, a receiving antenna and a processor, and the radar imaging device is used to implement the method according to any one of claims 1-9.

12. A computer-readable storage medium, wherein, The storage medium stores a computer program or instruction, and when the computer program or instruction is executed by the radar imaging device, the radar imaging device is caused to implement the method according to any one of claims 1-9.

13. A computer program product, wherein, The computer program product includes a computer program or instruction, and when the computer program or instruction is executed by the radar imaging device, the radar imaging device is caused to implement the method according to any one of claims 1-9.

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