Sensing system, receiving device, control circuit, storage medium, sensing method, and receiving method

Abstract

The present invention realizes a sensing system (40) capable of performing focus correction for an object to be measured at a short distance and performing high-resolution FFT imaging processing having suppressed aberration. The sensing system (40) comprises: a transmission device (10) that includes a transmission array antenna in the form of a plurality of transmission antenna elements (18), that controls the timings of the generation of a radar signal, the generation of a code, and the generation of a carrier signal, and that generates high-frequency signals and transmits said signals from the plurality of transmission antenna elements (18); and a reception device (20) that includes a reception array antenna in the form of a plurality of reception antenna elements (22) and receives the high-frequency signals, which have been reflected or scattered by the object to be measured, that generates transmission path information by using the carrier signal, the radar signal, and the code, identifies the position of the object to be measured, performs focus correction for the object to be measured, and thereby performs weighting processing on received signals for virtual antenna elements, and that generates an image of the object to be measured by performing fast Fourier transform processing.

Description

Sensing system, transmitting device, receiving device, control circuit, storage medium, sensing method, transmitting method and receiving method

[0001] The present disclosure relates to a sensing system, a transmitting device, a receiving device, a control circuit, a storage medium, a sensing method, a transmitting method, and a receiving method that visualize a measurement target using electromagnetic waves.

[0002] Conventionally, electromagnetic waves in the sub-terahertz band around 300 GHz have both penetration and high resolution, and are therefore expected to be applied to imaging technologies such as non-destructive testing and security gates. Generally, imaging using electromagnetic waves includes a technique for visualizing spatial information of a subject by combining beamforming, SAR (Synthetic Aperture Radar), etc. In SAR imaging, radio waves are irradiated onto a measurement target while a transmitting antenna and a receiving antenna are moved along a predetermined path, and the reflected waves can also be recorded as a received signal waveform.

[0003] However, because SAR imaging does not have a physical focus correction function such as a lens, large-scale correlation calculations are required to obtain an image of a subject from received signals, which poses a problem of the amount of calculation required for the correlation calculations. Fast Fourier Transformation (FFT) processing is generally known as a method for reducing the amount of calculation required for such correlation calculations. For example, Patent Document 1 discloses an imaging technology using FFT processing in a multiple input single output (MISO) or multiple input multiple output (MIMO) configuration.

[0004] JP 2013-15522 A

[0005] However, according to the above-mentioned conventional technology, the FFT imaging technology has a problem in that when the subject and the antenna are close to each other and the angle of view cannot be ignored relative to the distance between the subject and the antenna, blurring of the image occurs, which is called aberration.

[0006] The present disclosure has been made in consideration of the above, and aims to provide a sensing system that can perform focus correction for a measurement target at close range and perform high-resolution FFT imaging processing with reduced aberrations.

[0007] To solve the above-mentioned problems and achieve the object, the sensing system disclosed herein includes a transmitting device having a transmitting array antenna as a plurality of transmitting antenna elements, controlling the timing of generating a radar signal, generating a code for separating high-frequency signals transmitted from the plurality of transmitting antenna elements into high-frequency signals transmitted from each transmitting antenna element by a receiving device, and generating a carrier signal, multiplying the radar signal by the code for each of the plurality of transmitting antenna elements, generating high-frequency signals using the code-multiplied radar signal and the carrier signal, and transmitting the high-frequency signals from the plurality of transmitting antenna elements.The sensing system also includes a receiving device having a receiving array antenna as a plurality of receiving antenna elements, receiving the high-frequency signals transmitted from the transmitting device and reflected or scattered by an object to be measured, generating transmission path information indicating the state of the transmission path between the transmitting device and the receiving device using the carrier signal, radar signal, and code, identifying the position of the object to be measured using the transmission path information, performing weighting processing on the received signals of each virtual antenna element in accordance with the spatial position of the object to be measured in a received image obtained by performing focus correction on the object to be measured, and performing fast Fourier transform processing to generate an image of the object to be measured.

[0008] The sensing system of the present disclosure has the advantage of being able to perform focus correction for a measurement target at close range and perform high-resolution FFT imaging processing with reduced aberrations.

[0009] FIG. 1 is a diagram showing an overview of measurements assumed in a sensing system according to the first embodiment. FIG. 1 is a diagram showing an example of the configuration of a sensing system according to the first embodiment. FIG. 2 is a diagram showing an example of aberrations to be reduced when the sensing system according to the first embodiment generates an image. FIG. 3 is a flowchart showing the operation of a sensing system according to the first embodiment. FIG. 4 is a flowchart showing the operation of a transmitting device according to the first embodiment. FIG. 5 is a flowchart showing the operation of a receiving device according to the first embodiment. FIG. 6 is a diagram showing an example of the configuration of a processing circuit that realizes the transmitting device according to the first embodiment when it is realized by a processor and a memory. FIG. 7 is a diagram showing an example of the processing circuit that realizes the transmitting device according to the first embodiment when it is configured by dedicated hardware.

[0010] A sensing system, a transmitting device, a receiving device, a control circuit, a storage medium, a sensing method, a transmitting method, and a receiving method according to embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0011] First Embodiment. FIG. 1 is a diagram illustrating an overview of measurements assumed in a sensing system 40 according to a first embodiment. The sensing system 40 includes a transmitting device 10 and a receiving device 20, as described below, and measures an object 50. In the sensing system 40, the transmitting device 10 irradiates radio waves from a transmitting array 17 composed of multiple transmitting antenna elements 18 to the object 50, and the receiving device 20 receives reflected waves, scattered waves, etc. from the object 50 using a receiving array 21 composed of multiple receiving antenna elements 22, thereby measuring the object 50. The transmitting device 10 transmits high-frequency signals as the radio wave irradiation. As described below, the sensing system 40 extracts information about the object 50 from information about a transmission path formed between a transmitting linear array antenna, which is the transmitting array 17 composed of multiple transmitting antenna elements 18, and a receiving linear array antenna, which is the receiving array 21 composed of multiple receiving antenna elements 22.

[0012] 2 is a diagram showing an example of the configuration of a sensing system 40 according to embodiment 1. As described above, the sensing system 40 includes a transmitting device 10 and a receiving device 20. The transmitting device 10 includes a synchronization unit 11, a radar signal generating unit 12, a code generating unit 13, a carrier signal generating unit 14, an encoding unit 15, a high-frequency signal generating unit 16, and a transmitting array 17. The transmitting array 17 includes a plurality of transmitting antenna elements 18.

[0013] The synchronization unit 11 adjusts the timing of operation of each unit in the transmitting device 10 and the receiving device 20. The synchronization unit 11 controls the timing of radar signal generation by the radar signal generation unit 12, code generation by the code generation unit 13, and carrier signal generation by the carrier signal generation unit 14 in the transmitting device 10. The radar signal generation unit 12 generates a radar signal at baseband or an intermediate frequency. The radar signal is, for example, a periodic wideband signal. The code generation unit 13 generates a code for separating a high-frequency signal transmitted from a transmitting array 17 including multiple transmitting antenna elements 18 into high-frequency signals transmitted from each transmitting antenna element 18 in the receiving device 20. The carrier signal generation unit 14 generates a reference carrier for generating a final high-frequency signal. For example, the carrier signal generation unit 14 divides the frequency band available to the transmitting device 10 into multiple subbands and periodically switches the subbands used in the high-frequency signals transmitted from the multiple transmitting antenna elements 18 to generate a carrier signal so that the entire frequency band is used.

[0014] The encoder 15 performs code multiplication for each of the plurality of transmitting antenna elements 18, multiplying the radar signal generated by the radar signal generator 12 by the code generated by the code generator 13. The radio-frequency signal generator 16 generates a radio-frequency signal to be transmitted from each of the transmitting antenna elements 18, using the signal obtained by multiplying the radar signal by the code generated by the encoder 15 and the reference carrier generated by the carrier signal generator 14. The radio-frequency signal generator 16 is, for example, an upconverter or a multiplier, and generates radio-frequency signals of a subband bandwidth using the code-multiplied radar signal and the carrier signal, and transmits the radio-frequency signals from the plurality of transmitting antenna elements 18. In the transmitting array 17, the transmitting antenna elements 18 transmit the radio-frequency signals generated by the radio-frequency signal generator 16. The transmitting device 10 has transmitting linear array antennas as the plurality of transmitting antenna elements 18.

[0015] The receiving device 20 includes a receiving array 21, a signal conversion unit 23, a detection unit 24, a correlation processing unit 25, a MIMO transmission path regeneration unit 26, a layer extraction unit 27, a focus correction unit 28, a weighting processing unit 29, and an FFT processing unit 30. The receiving array 21 includes a plurality of receiving antenna elements 22.

[0016] In the receiving array 21, the receiving antenna elements 22 receive the high-frequency signals transmitted from the transmitting device 10, which are reflected waves or scattered waves from the target 50. That is, the receiving antenna elements 22 receive the reflected waves or scattered waves of the high-frequency signals transmitted from the transmitting device 10. Note that the receiving antenna elements 22 can also directly receive the high-frequency signals transmitted from the transmitting device 10, depending on the positional relationship and orientation between the transmitting antenna elements 18 of the transmitting device 10 and the receiving antenna elements 22 of the receiving device 20. The receiving device 20 has a receiving linear array antenna as the multiple receiving antenna elements 22. For each receiving antenna element 22, the signal converter 23 converts the high-frequency signals received by the receiving antenna elements 22 into baseband or intermediate frequency signals, i.e., downconverts them. The signal converter 23 is, for example, a downconverter, and converts the high-frequency signals received by the multiple receiving antenna elements 22 into received signals in the frequency band of the radar signal used to generate the high-frequency signals in the transmitting device 10, using the carrier signal used to generate the high-frequency signals in the transmitting device 10.

[0017] The detector 24 is provided for each receiving antenna element 22, and detects the baseband or intermediate frequency received signal converted by the signal converter 23 using the radar signal generated by the radar signal generator 12 of the transmitting device 10 to obtain reception information. The reception information includes reflected waves or scattered waves of the high-frequency signal received by each receiving antenna element 22, which are high-frequency signals transmitted from the multiple transmitting antenna elements 18. Note that the receiving device 20 may obtain reception information by mixing the baseband or intermediate frequency received signals converted by the signal converter 23 using a mixer. The following describes the case where the detector 24 performs detection. The correlation processing unit 25 is arranged for each receiving antenna element 22, and uses the code generated by the code generation unit 13 of the transmitting device 10 to perform correlation processing on the received information obtained by detection by the detection unit 24, thereby separating the received information into signals from each transmitting antenna element 18 of the transmitting device 10, i.e., separating the received signals received by multiple receiving antenna elements 22 into signals for each transmitting antenna element 18 transmitted from the transmitting device 10 for each receiving antenna element 22.

[0018] The MIMO transmission path reproducing unit 26 reproduces the state of the transmission path between the transmitting device 10 and the receiving device 20 using the signals separated by the correlation processing unit 25 for each transmitting antenna element 18 and each receiving antenna element 22, and generates MIMO transmission path information indicating the state of the transmission path. The MIMO transmission path reproducing unit 26 generates the MIMO transmission path information for each frequency bin described below. In the following description, the MIMO transmission path reproducing unit may be simply referred to as the transmission path reproducing unit, and the MIMO transmission path information may be simply referred to as the transmission path information. The layer extracting unit 27 identifies the position of the measurement target 50 using the MIMO transmission path information. The layer extracting unit 27 extracts the measurement target 50 using a specific curved surface from the MIMO transmission path information reproduced by the MIMO transmission path reproducing unit 26. Specifically, the layer extraction unit 27 identifies the position of the measurement object 50 by extracting reflection point information of a layer corresponding to the depth distance of the measurement object 50 from the multiple receiving antenna elements 22 from the MIMO transmission path information.

[0019] The focus correction unit 28 performs focus correction on the target 50 whose position has been identified, generating a received image of the target 50. The focus correction unit 28 performs focus correction on the extracted reflection point information according to the layer position as the focus correction for the target 50. The weighting processing unit 29 performs weighting processing using the received image obtained by the focus correction by the focus correction unit 28. The weighting processing is a process of weighting the received signals of each virtual antenna element according to the spatial position of the target 50 in the received image. The virtual antenna elements are virtual two-dimensional array elements obtained by combining the transmitting antenna elements 18 of the transmitting linear array antenna and the receiving antenna elements 22 of the receiving linear array antenna. The received image is an image obtained by combining the received signals of the virtual antenna elements. The weighting processing unit 29 weights the received signals of virtual antenna elements with minimal phase error. The FFT processing unit 30 performs two-dimensional FFT processing on the received signals of each virtual antenna element weighted by the weighting processing unit 29, generating and outputting an image that is image information of the target 50. In the following description, FFT may be referred to as fast Fourier transform, and two-dimensional FFT processing may be simply referred to as FFT processing.

[0020] The operation of the sensing system 40 will now be described. In the transmitting device 10, the synchronization unit 11 controls the radar signal generation timing of the radar signal generation unit 12, the code generation timing of the code generation unit 13, and the carrier frequency switching timing of the carrier signal generation unit 14. The radar signal generation unit 12 generates a radar signal using, for example, an up-chirp, but is not limited to, an up-chirp. The radar signal generated by the radar signal generation unit 12 may be any signal whose spectrum spreads across a specific frequency band, such as an up-down chirp, a ZC (Zadoff-Chu) sequence, a pseudo-noise (hereinafter referred to as PN) signal, an OFDM (Orthogonal Frequency Division Multiplexing) signal, a frequency step signal whose frequency changes stepwise in the time direction, or a general spread signal.

[0021] The radar signal generator 12 generates a periodic wideband signal, typically a chirp signal, in each subband as a radar signal. At this time, the synchronizer 11 instructs the radar signal generator 12 about the start timing of each period. The period of the wideband signal is, for example, a chip period T where A is an integer. Ｃ That is, the code generator 13 sets the code chip period T Ｃ The code generator 13 generates a code having a code length of M chips to be used by each transmitting antenna element 18. Note that the code period T ＳＣ = M x T Ｃ At this time, the synchronization unit 11 transmits the code period T ＳＣ The encoder 15 performs code multiplication, which multiplies the radar signal generated by the radar signal generator 12 by the code generated by the code generator 13. The code is generally expressed as ±1. The encoder 15 performs multiplication processing as phase modulation, amplitude modulation, frequency modulation, or a combination of these.

[0022] The transmitter 10 transmits at least a code period T ＳＣ However, by repeatedly using the code, the radar signal is transmitted with a code period T ＳＣ The radar signal may be transmitted for the above period of time, for example, the subband switching period. When the transmitter 10 finishes transmitting the radar signal in one subband for the subband switching period, the transmitter 10 switches the frequency, i.e., switches the subband.

[0023] The carrier signal generator 14 generates carrier signals for converting the radar signals encoded by the encoder 15 into radio frequency signals of each subband. The carrier signal generator 14 receives instructions from the synchronizer 11 and generates appropriate carrier signals to switch subbands at each subband switching period. The radio frequency signal generator 16 uses the carrier signals generated by the carrier signal generator 14 to convert the radar signals encoded by the encoder 15 into radio frequency signals of each subband, and transmits the signals from the transmitting antenna elements 18 of the transmitting array 17.

[0024] The codes generated by the code generation unit 13 are used to identify signals between elements of the transmitting antenna elements 18. For this reason, the code generation unit 13 generates so-called orthogonal codes or quasi-orthogonal codes that have small cross-correlation between elements of the transmitting antenna elements 18. Note that, although M sequences, Gold codes, Walsh-Hadamard codes, PN sequences, etc. are known as the codes generated by the code generation unit 13 and used to identify signals between elements of the transmitting antenna elements 18, any code with a high degree of orthogonality may be used, and therefore the codes are not limited to these.

[0025] In the sensing system 40, the transmitting device 10 and the receiving device 20 are synchronized in both time and frequency, and operate under the instructions of the same synchronization unit 11 as shown in FIG.

[0026] The receiving device 20 receives, at the receiving antenna elements 22 of the receiving array 21, high-frequency signals that are irradiated from the transmitting device 10 to the target 50 and reflected or scattered by the target 50. The signal conversion unit 23 converts, i.e., downconverts, the high-frequency signals received by the receiving antenna elements 22 of the receiving array 21 into baseband or intermediate frequency signals using carrier signals corresponding to each subband generated by the carrier signal generation unit 14. The detection unit 24 is provided for each receiving antenna element 22 and detects the baseband or intermediate frequency signals converted by the signal conversion unit 23 using the radar signal generated by the radar signal generation unit 12 of the transmitting device 10 to obtain reception information. The reception information includes signals transmitted from all transmitting antenna elements 18 in the form received by a specific receiving antenna element 22.

[0027] The correlation processing unit 25 uses the code generated by the code generation unit 13 of the transmitting device 10 to perform correlation processing on the received information obtained by detection by the detection unit 24, thereby separating the received information into signals from each transmitting antenna element 18 of the transmitting device 10. In the receiving device 20, the processing of the correlation processing unit 25 is performed for each receiving antenna element 22, so that transmission path information for each subband is obtained by multiplying the number of transmitting antenna elements 18 by the number of receiving antenna elements 22. Note that the detection processing in the detection unit 24 differs depending on the type of signal used as the radar signal, so a detailed description will be omitted here. In the first embodiment, the detection processing in the detection unit 24 may be performed using a general-purpose processing method.

[0028] The extent to which the subband bandwidth is widened depends on the frequency band used by the sensing system 40, various architectures, and the like. In particular, when the sensing system 40 uses an ultra-high frequency band such as the terahertz band, there is a high possibility that large fluctuations in frequency characteristics will occur within the subband. Therefore, the sensing system 40 may calculate the transmission channel information by dividing the subband bandwidth into multiple frequency bins. Generally, the frequency bins are set to bandwidths within which frequency fluctuations within the band are considered constant. In the receiving device 20, the MIMO transmission channel regeneration unit 26 divides each subband into frequency bins and calculates the transmission channel information formed by sandwiching the target 50 between the transmitting array 17 of the transmitting device 10 and the receiving array 21 of the receiving device 20 shown in FIG. 1 . As a result, the MIMO transmission channel regeneration unit 26 can obtain MIMO transmission channel information that integrates the information of all subbands. The method for generating the MIMO transmission path information in the MIMO transmission path regeneration unit 26 differs depending on the type of radar signal, the detection method, etc., but the method for generating the MIMO transmission path information is not limited here. The obtained MIMO transmission path information includes information from all reflection points of the measurement target 50.

[0029] The layer cutout unit 27 cuts out only reflection point information on a specific curved surface determined by the arrangement of the transmitting antenna elements 18 and the receiving antenna elements 22. Note that the specific curved surface may also be a specific plane. The focus correction unit 28 can obtain a tomographic image of any portion of the measurement target 50 by focusing on the curved surface. The focus correction unit 28 performs focus correction, for example, by multiplying the received signals of each receiving antenna element 22 by a correction coefficient such that the phase of the scattered radio waves is the same on the specific surface. Note that the processing of the layer cutout unit 27 and the processing of the focus correction unit 28 can be performed in any order. Furthermore, if the measurement target 50 is made of an opaque material and the main reflection points remain on the target surface, the layer cutout processing of the layer cutout unit 27 can be omitted.

[0030] Here, we will explain why aberrations occur when a system such as the sensing system 40 generates an image. FIG. 3 is a diagram showing an example of aberrations that the sensing system 40 according to the first embodiment reduces when generating an image. When the sensing system 40 generates an image, the phase error of the reflected waves increases as the scattering point coordinates move away from the focus or the positions of the transmitting antenna element 18 and the receiving antenna element 22 move away from the center. This phase error causes blurring of the image, known as aberration, during image generation. Therefore, in this embodiment, the receiving device 20 applies weighting to the received signals of each virtual antenna element according to the spatial position of the target 50 in the received image obtained from the received signals of the virtual antenna elements based on the arrangement of multiple transmitting linear array antennas (the transmitting array 17) and the arrangement of multiple receiving linear array antennas (the receiving array 21). The weighting is applied to the received signals of each virtual antenna element with the smallest phase error, and FFT processing is then performed to reduce the aberration.

[0031] In this embodiment, the weighting processing unit 29 performs weighting processing on the received signal of each virtual antenna element and reduces phase errors by applying a window function to the received image whose focus has been corrected by the focus correction unit 28. The FFT processing unit 30 performs FFT processing using the received signal of each virtual antenna element that has been weighted by the weighting processing unit 29, and generates an image of the object 50 to be measured.

[0032] 4 is a flowchart showing the operation of the sensing system 40 according to the first embodiment. In the sensing system 40, the transmitting device 10 generates a high-frequency signal (step S11) and transmits it from the transmitting array 17 toward the object of measurement 50 (step S12). When the receiving device 20 receives the high-frequency signal transmitted from the transmitting device 10 and reflected or scattered by the object of measurement 50 (step S13), it generates MIMO transmission path information indicating the state of the transmission path between the transmitting device 10 and the receiving device 20 using the carrier signal, radar signal, and code (step S14). The receiving device 20 then identifies the position of the object of measurement 50 using the MIMO transmission path information, performs focus correction on the object of measurement 50, and performs weighting and FFT processing to generate an image of the object of measurement 50 (step S15).

[0033] FIG. 5 is a flowchart showing the operation of the transmitting device 10 according to the first embodiment. The flowchart shown in FIG. 5 shows details of the operations of steps S11 and S12 of the flowchart shown in FIG. 4. In the transmitting device 10, the synchronization unit 11 controls the timing of the radar signal generation by the radar signal generation unit 12, the code generation by the code generation unit 13, and the carrier signal generation by the carrier signal generation unit 14, i.e., the timing of each operation (step S21). The radar signal generation unit 12 generates a wideband radar signal under the control of the synchronization unit 11 (step S22). The code generation unit 13 generates a code under the control of the synchronization unit 11 for separating the high-frequency signals transmitted from the multiple transmitting antenna elements 18 into the high-frequency signals transmitted from each transmitting antenna element 18 in the receiving device 20 (step S23). The encoding unit 15 multiplies the radar signal by the code for each of the multiple transmitting antenna elements 18 (step S24). The carrier signal generator 14, under the control of the synchronizer 11, divides the frequency band available to the transmitter 10 into multiple subbands and periodically switches the subbands used in the high-frequency signals transmitted from the multiple transmitting antenna elements 18 to generate carrier signals so that the entire frequency band is used (step S25). The high-frequency signal generator 16 generates high-frequency signals of the subband bandwidths using the code-multiplied radar signal and the carrier signal (step S26). The multiple transmitting antenna elements 18 transmit the high-frequency signals (step S27).

[0034] FIG. 6 is a flowchart showing the operation of the receiving device 20 according to the first embodiment. The flowchart shown in FIG. 6 shows details of the operation from step S13 to step S15 of the flowchart shown in FIG. 4. In the receiving device 20, the multiple receiving antenna elements 22 receive reflected or scattered waves of a high-frequency signal transmitted from the transmitting device 10 having multiple transmitting antenna elements 18 and reflected or scattered by the object to be measured 50 (step S31). The signal conversion unit 23 converts the reflected or scattered waves of the high-frequency signal received by the multiple receiving antenna elements 22 into received signals in the frequency band of the radar signal used to generate the high-frequency signal by the transmitting device 10, using the carrier signal used to generate the high-frequency signal by the transmitting device 10 (step S32). The detection unit 24 detects the received signals using the radar signal generated by the transmitting device 10, and obtains reception information including the reflected or scattered waves of the high-frequency signal received by each receiving antenna element 22 and the high-frequency signal transmitted from the multiple transmitting antenna elements 18 (step S33).

[0035] The correlation processing unit 25 performs correlation processing on the received information using the code used when the radar signal was encoded by the transmitting device 10, and separates the received signal into signals for each receiving antenna element 22 and for each transmitting antenna element 18 transmitted from the transmitting device 10 (step S34). The MIMO transmission path regeneration unit 26 uses the separated signals to generate MIMO transmission path information indicating the state of the transmission path between the transmitting device 10 and the receiving device 20 (step S35). The layer extraction unit 27 identifies the position of the measurement target 50 using the MIMO transmission path information (step S36). The focus correction unit 28 performs focus correction on the measurement target 50 whose position has been identified (step S37). The weighting processing unit 29 performs weighting processing on the received signal of each virtual antenna element according to the spatial position of the measurement target 50 in the received image obtained by the focus correction unit 28 performing focus correction on the measurement target 50, thereby reducing phase error (step S38). The FFT processing unit 30 performs FFT processing using the received signals of each virtual antenna element weighted by the weighting processing unit 29, and generates an image of the object 50 to be measured (step S39).

[0036] Next, the hardware configuration of each device in the sensing system 40 will be described. In the transmitting device 10, the transmitting array 17 is composed of a plurality of transmitting antenna elements 18. The synchronization unit 11, radar signal generation unit 12, code generation unit 13, carrier signal generation unit 14, encoding unit 15, and high frequency signal generation unit 16 are realized by processing circuits. The processing circuit may be a processor and memory that executes a program stored in memory, or may be dedicated hardware. The processing circuit is also called a control circuit.

[0037] FIG. 7 is a diagram illustrating an example of the configuration of a processing circuit 90 that implements the transmitting device 10 according to the first embodiment when the processing circuit is implemented by a processor 91 and a memory 92. The processing circuit 90 illustrated in FIG. 7 is a control circuit and includes a processor 91 and a memory 92. When the processing circuit 90 is configured with the processor 91 and the memory 92, each function of the processing circuit 90 is implemented by software, firmware, or a combination of software and firmware. The software or firmware is written as a program and stored in the memory 92. The processing circuit 90 implements each function by having the processor 91 read and execute the program stored in the memory 92. That is, the processing circuit 90 includes the memory 92 for storing a program that results in the processing of the transmitting device 10 being executed. This program can also be said to be a program that causes the transmitting device 10 to execute each function implemented by the processing circuit 90. This program may be provided by a storage medium on which the program is stored, or by other means such as a communication medium.

[0038] It can also be said that the above program causes the transmitting device 10 to execute the following steps: a radar signal generation step in which the radar signal generation unit 12 generates a radar signal that is a wideband signal; a code generation step in which the code generation unit 13 generates a code for separating the high-frequency signals transmitted from the multiple transmitting antenna elements 18 into high-frequency signals transmitted from each transmitting antenna element 18 by the receiving device 20; a coding step in which the coding unit 15 multiplies the radar signal by a code for each of the multiple transmitting antenna elements 18; a carrier signal generation step in which the carrier signal generation unit 14 divides the frequency band available to the transmitting device 10 into multiple subbands and periodically switches the subbands used in the high-frequency signals transmitted from the multiple transmitting antenna elements 18 to generate carrier signals so that the entire frequency band is used; a high-frequency signal generation step in which the high-frequency signal generation unit 16 uses the radar signal multiplied by the code and the carrier signal to generate high-frequency signals of the subband bandwidths and transmit them from the multiple transmitting antenna elements 18; and a synchronization step in which the synchronization unit 11 controls the timing of generating the radar signal, the code, and the carrier signal.

[0039] Here, the processor 91 is, for example, a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor), etc. The memory 92 is, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (Electrically EPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD (Digital Versatile Disc).

[0040] FIG. 8 is a diagram illustrating an example of a processing circuit 93 that implements the transmitting device 10 according to the first embodiment when the processing circuit is configured with dedicated hardware. The processing circuit 93 illustrated in FIG. 8 corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The processing circuit may be partially implemented with dedicated hardware and partially implemented with software or firmware. In this way, the processing circuit can implement each of the above-described functions by dedicated hardware, software, firmware, or a combination thereof.

[0041] The hardware configuration of the transmitting device 10 has been described above, but the hardware configuration of the receiving device 20 is also similar. In the receiving device 20, the receiving array 21 is composed of a plurality of receiving antenna elements 22. The signal conversion unit 23, the detection unit 24, the correlation processing unit 25, the MIMO transmission path regeneration unit 26, the layer extraction unit 27, the focus correction unit 28, the weighting processing unit 29, and the FFT processing unit 30 are realized by processing circuits. The processing circuit may be a processor and memory that executes a program stored in memory, or may be dedicated hardware. The processing circuit is also called a control circuit.

[0042] As described above, according to this embodiment, in the sensing system 40, the transmitting device 10 controls the timing of radar signal generation, code generation, and carrier signal generation, generates high-frequency signals of subband bandwidths, and transmits them from the multiple transmitting antenna elements 18. The receiving device 20 receives the high-frequency signals transmitted from the transmitting device 10 and reflected or scattered by the target 50, generates MIMO transmission path information using the carrier signal, radar signal, and code generated by the transmitting device 10, and identifies the position of the target 50. The receiving device 20 further performs focus correction on the target 50 whose position has been identified, performs weighting processing to assign weights to the received signals of each virtual antenna element with minimal phase error according to the spatial position of the target 50 in the focus-corrected received image, and generates an image of the target 50 by performing FFT processing using the weighted received signals of each virtual antenna element. This allows the sensing system 40 to improve the resolution when measuring a short-distance target 50 at low cost while using high-frequency signals. The sensing system 40 acquires reflection and scattering information over a wide frequency band, which is necessary for high-resolution imaging, and is capable of imaging at a desired distance, i.e., tomography. The sensing system 40 also performs focus correction for a measurement target 50 at close range, and can perform high-resolution FFT imaging processing with reduced aberrations.

[0043] In this embodiment, the weighting process performed by the receiving device 20 to reduce aberration is a method of applying weighting to the received signal of each virtual antenna element, and is a different technique from the weighting process that is generally used in SAR radar and is intended to suppress side lobes.

[0044] In the above description, a case where multiple subbands are used has been described, but the number of subbands may also be 1. In addition, in the above description, a case where a transmitting linear array antenna, which is a transmitting array 17 having multiple transmitting antenna elements 18, and a receiving linear array antenna, which is a receiving array 21 having multiple receiving antenna elements 22, has been described, but it is also possible to use a transmitting array antenna and a receiving array antenna that are not linear.

[0045] Second Embodiment In the second embodiment, a specific case will be described in which the transmitting device 10 has two rows of transmitting linear array antennas as the transmitting array 17, and the receiving device 20 has two rows of receiving linear array antennas as the receiving array 21.

[0046] In the second embodiment, the configuration of the sensing system 40 is the same as the configuration of the sensing system 40 in the first embodiment shown in Fig. 2. In the second embodiment, the sensing system 40 is a system with a 2x2 MIMO configuration. Fig. 9 is a diagram showing an image of the sensing system 40 with a 2x2 MIMO configuration according to the second embodiment. Fig. 10 is a diagram showing an image of a received image obtained by the sensing system 40 with a 2x2 MIMO configuration according to the second embodiment. Fig. 11 is a diagram showing an example of weighting processing performed by the weighting processing unit 29 included in the sensing system 40 with a 2x2 MIMO configuration according to the second embodiment.

[0047] In the second embodiment, the antenna configuration of the sensing system 40 is as shown in FIG. 9 , in which the transmitting device 10 has two rows of transmitting linear array antennas as the transmitting array 17, and the receiving device 20 has two rows of receiving linear array antennas as the receiving array 21, with the two rows of transmitting linear array antennas Tx1 and Tx2 and the two rows of receiving linear array antennas Rx1 and Rx2 being arranged in a square shape so as to be orthogonal to each other. In the second embodiment, the sensing system 40 irradiates radio waves, i.e., high-frequency signals, from the two rows of transmitting linear array antennas Tx1 and Tx2 to the object of measurement 50, and receives the radio waves, i.e., high-frequency signals, reflected or scattered by the object of measurement 50 with the two rows of receiving linear array antennas Rx1 and Rx2, thereby imaging the object of measurement 50 in a 2×2 MIMO configuration, i.e., generating an image. Note that in the second embodiment, the operation of each unit of the transmitting device 10 and the receiving device 20 is the same as the operation of each unit of the transmitting device 10 and the receiving device 20 in the first embodiment.

[0048] In the second embodiment, the receiving device 20 receives signals reflected or scattered by the object to be measured 50, and obtains a received image as shown in FIG. 10 , which is divided into 2×2 cells corresponding to virtual two-dimensional array elements obtained by combining two rows of transmitting linear array antennas Tx1 and Tx2 and two rows of receiving linear array antennas Rx1 and Rx2.

[0049] 10 , the cells indicated by Tx1→Rx1 are cells of the received image based on the reflected or scattered waves of the high-frequency signal by the object to be measured 50, which were transmitted from the transmitting linear array antenna Tx1 and received by the receiving linear array antenna Rx1. Furthermore, the cells indicated by Tx1→Rx2 are cells of the received image based on the reflected or scattered waves of the high-frequency signal by the object to be measured 50, which were transmitted from the transmitting linear array antenna Tx1 and received by the receiving linear array antenna Rx2. Furthermore, the cells indicated by Tx2→Rx1 are cells of the received image based on the reflected or scattered waves of the high-frequency signal by the object to be measured 50, which were transmitted from the transmitting linear array antenna Tx2 and received by the receiving linear array antenna Rx1. Furthermore, the cells indicated by Tx2→Rx2 are cells of the received image based on the reflected or scattered waves of the high-frequency signal by the object to be measured 50, which were transmitted from the transmitting linear array antenna Tx2 and received by the receiving linear array antenna Rx2. The receiving device 20 applies a window function that spatially weights the received image shown in FIG. 10 in consideration of the position of the object 50 to be measured, and performs FFT processing to generate an image with reduced aberration.

[0050] At this time, the weighting processing unit 29 of the receiving device 20 performs weighting processing, for example, as shown in FIG. 11. a. Weighting only the cell including the location of the measurement target 50. b. Weighting the cell including the location of the measurement target 50 plus some of the adjacent cells. c. Weighting the entire cell including the location of the measurement target 50 plus the adjacent cells. d. Weighting in a circular pattern to include the cell corresponding to the location of the measurement target 50. Note that while the above description is simplified, in reality, the "cell" portion of the weighting target is the "received signal of each virtual antenna element corresponding to the cell." The range of data used shown in FIG. 11 is the range weighted by the weighting processing unit 29. Note that the weighting processing shown in FIG. 11 is an example, and the weighting processing unit 29 may perform weighting processing using methods other than a to d shown in FIG. 11.

[0051] As described above, in the second embodiment, the weighting processing unit 29 in the receiving device 20 applies a window function to the received signal of each virtual antenna element in accordance with the spatial position of the object to be measured 50 in the received image divided into 2 × 2 cells corresponding to the virtual two-dimensional array elements obtained by combining the arrangement of the two rows of transmitting linear array antennas Tx1 and Tx2 and the arrangement of the two rows of receiving linear array antennas Rx1 and Rx2. Thereafter, the FFT processing unit 30 in the receiving device 20 performs FFT processing to generate an image of the object to be measured 50.

[0052] Embodiment 3 In Embodiment 3, the arrangement of the transmitting linear array antennas Tx1 and Tx2 and the arrangement of the receiving linear array antennas Rx1 and Rx2 in Embodiment 2 are generalized, and a case will be described in which the transmitting device 10 has N rows of transmitting linear array antennas Tx as the transmitting array 17, and the receiving device 20 has M rows of receiving linear array antennas Rx as the receiving array 21. Note that N and M are positive integers. Embodiment 2 corresponds to the case in which both N and M are 2.

[0053] In the third embodiment, the configuration of the sensing system 40 is the same as the configuration of the sensing system 40 in the first embodiment shown in Fig. 2. In the third embodiment, the sensing system 40 is a system with an NxM MIMO configuration. Fig. 12 is a diagram showing an image of the sensing system 40 with an NxM MIMO configuration according to the third embodiment. Fig. 13 is a diagram showing an image of a received image obtained by the sensing system 40 with an NxM MIMO configuration according to the third embodiment. Fig. 14 is a diagram showing an example of weighting processing performed by the weighting processing unit 29 included in the sensing system 40 with an NxM MIMO configuration according to the third embodiment.

[0054] In the third embodiment, the antenna configuration of the sensing system 40 is as shown in FIG. 12 , in which the transmitting device 10 has N rows of transmitting linear array antennas Tx as the transmitting array 17, and the receiving device 20 has M rows of receiving linear array antennas Rx as the receiving array 21, with the N rows of the transmitting linear array antennas Tx and the M rows of the receiving linear array antennas Rx arranged so as to be orthogonal to each other. In the third embodiment, the sensing system 40 irradiates radio waves, i.e., high-frequency signals, from the N rows of transmitting linear array antennas Tx to the object 50 to be measured, and receives the radio waves, i.e., high-frequency signals, reflected or scattered by the object 50 with the M rows of receiving linear array antennas Rx, thereby imaging the object 50 to generate an image using an N×M MIMO configuration. Note that in the third embodiment, the operation of each unit of the transmitting device 10 and the receiving device 20 is the same as the operation of each unit of the transmitting device 10 and the receiving device 20 in the first embodiment.

[0055] In the third embodiment, the receiving device 20 receives signals reflected or scattered by the target 50 and obtains a received image as shown in FIG. 13 , which is divided into N×M cells corresponding to the virtual two-dimensional array elements obtained by combining N rows of transmitting linear array antennas Tx and M rows of receiving linear array antennas Rx. In FIG. 13 , the relationship between the combination of the transmitting linear array antennas Tx and the receiving linear array antennas Rx and each cell is the same as in the case of FIG. 10 described in the second embodiment, and therefore a detailed description thereof will be omitted. Note that the denser the N rows of transmitting linear array antennas Tx and M rows of receiving linear array antennas Rx are, i.e., the larger the values ​​of N and M are, the greater the overlap of data between nearby cells in the received image. The receiving device 20 applies a window function that spatially weights the received image shown in FIG. 13 in consideration of the position of the target 50, and performs FFT processing to generate an image with reduced aberrations.

[0056] At this time, the weighting processing unit 29 of the receiving device 20 performs weighting processing, for example, as shown in Fig. 14. The content is similar to the example of Fig. 11 explained in the second embodiment, so detailed description will be omitted. Note that the weighting processing shown in Fig. 14 is just one example, and the weighting processing unit 29 may perform weighting processing using methods other than a to d shown in Fig. 14. In the case of Fig. 14, as in the case of Fig. 11, the "cell" portion to be weighted actually becomes "the received signal of each virtual antenna element corresponding to the cell."

[0057] As described above, in the third embodiment, the weighting processing unit 29 in the receiving device 20 applies a window function that spatially weights the received signal of each virtual antenna element according to the spatial position of the object to be measured 50 in the received image divided into N × M cells corresponding to the virtual two-dimensional array elements obtained by combining the N-column arrangement of the transmitting linear array antenna Tx and the M-column arrangement of the receiving linear array antenna Rx, thereby performing weighting processing. Thereafter, the FFT processing unit 30 in the receiving device 20 performs FFT processing to generate an image of the object to be measured 50.

[0058] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0059] 10 Transmitting device, 11 Synchronization unit, 12 Radar signal generation unit, 13 Code generation unit, 14 Carrier signal generation unit, 15 Encoding unit, 16 High frequency signal generation unit, 17 Transmitting array, 18 Transmitting antenna element, 20 Receiving device, 21 Receiving array, 22 Receiving antenna element, 23 Signal conversion unit, 24 Detection unit, 25 Correlation processing unit, 26 MIMO transmission path reproduction unit, 27 Layer extraction unit, 28 Focus correction unit, 29 Weighting processing unit, 30 FFT processing unit, 40 Sensing system, 50 Measurement target, 90, 93 Processing circuit, 91 Processor, 92 Memory.

Claims

1. A transmitting device having a transmitting array antenna as multiple transmitting antenna elements, controlling the timing of generating a radar signal, generating a code for separating the high-frequency signals transmitted from the multiple transmitting antenna elements into the high-frequency signals transmitted from each transmitting antenna element by a receiving device, and generating a carrier signal, multiplying the radar signal and the code for each of the multiple transmitting antenna elements, generating the high-frequency signal using the radar signal multiplied by the code and the carrier signal, and transmitting it from the multiple transmitting antenna elements, A receiving device having a receiving array antenna as multiple receiving antenna elements, receiving the high-frequency signal transmitted from the transmitting device and reflected or scattered by the object to be measured, generating transmission path information indicating the state of the transmission path between the transmitting device and the receiving device using the carrier signal, the radar signal, and the code, identifying the position of the object to be measured using the transmission path information, performing a focus correction on the object to be measured and weighting the received signals of each virtual antenna element according to the spatial position of the object to be measured in the obtained received image, and performing a fast Fourier transform to generate an image of the object to be measured. A sensing system characterized by having the following features.

2. The transmitting device is The available frequency band is divided into multiple subbands, and the carrier signal is generated by periodically switching the subbands used in the high-frequency signals transmitted from multiple transmitting antenna elements so that the entire frequency band is used. The high-frequency signal generated using the radar signal and the carrier signal multiplied by the aforementioned code is a high-frequency signal with the bandwidth of the subband. The sensing system according to feature 1.

3. The aforementioned transmitting array antenna is a transmitting linear array antenna. The receiving array antenna is a receiving linear array antenna. The sensing system according to feature 1 or 2.

4. Let N and M be positive integers. The transmitting device has N rows of the transmitting linear array antennas as the plurality of transmitting antenna elements. The receiving device has M rows of receiving linear array antennas arranged orthogonally to the N-row arrangement of the transmitting linear array antennas, and performs the weighting process by applying a spatially weighted window function to the received signals of each virtual antenna element corresponding to the spatial position of the object to be measured in the received image, which is divided into N × M cells corresponding to a virtual two-dimensional array element obtained by the combination of the N-row arrangement of the transmitting linear array antennas and the M-row arrangement of the receiving linear array antennas, and then performs the fast Fourier transform process to generate an image of the object to be measured. The sensing system according to feature 3.

5. Let N and M be set to 2. The transmitting device has two rows of the transmitting linear array antennas as the plurality of transmitting antenna elements. The receiving device has two rows of receiving linear array antennas as the plurality of receiving antenna elements, orthogonal to the two rows of transmitting linear array antennas, and applies the window function to the received signal of each virtual antenna element corresponding to the spatial position of the object to be measured in the received image, which is divided into 2x2 cells corresponding to the virtual two-dimensional array elements obtained by the combination of the two rows of transmitting linear array antennas and the two rows of receiving linear array antennas, to perform the weighting process and perform the fast Fourier transform process to generate an image of the object to be measured. The sensing system according to feature 4.

6. A receiving device that receives reflected or scattered waves of a high-frequency signal transmitted from a transmitting device having a plurality of receiving linear array antennas as receiving antenna elements and a plurality of transmitting linear array antennas as transmitting antenna elements, and which is reflected or scattered by a target to be measured, A signal conversion unit converts the reflected or scattered waves of the high-frequency signal received by a plurality of receiving antenna elements into a received signal in the frequency band of the radar signal used to generate the high-frequency signal in the transmitting device, using the carrier signal used to generate the high-frequency signal in the transmitting device. A detection unit that uses the radar signal to detect the received signal and obtains received information which includes the reflected or scattered waves of the high-frequency signal received by each receiving antenna element and the high-frequency signal transmitted from a plurality of transmitting antenna elements, A correlation processing unit performs correlation processing on the received information using the code used when the radar signal was encoded by the transmitting device, and separates the received signal into signals for each transmitting antenna element transmitted from the transmitting device for each receiving antenna element, A transmission path regeneration unit generates transmission path information indicating the state of the transmission path between the transmitting device and the receiving device using the separated signals, A layer extraction unit that identifies the position of the object to be measured using the aforementioned transmission path information, A focus correction unit that performs focus correction on the measurement target whose position has been identified, A weighting processing unit performs weighting processing on the received signals of each virtual antenna element according to the spatial position of the object to be measured in the received image obtained by the focus correction of the focus correction unit, A fast Fourier transform processing unit performs a fast Fourier transform on the received signals of each virtual antenna element weighted by the weighting processing unit to generate an image of the object to be measured, A receiving device characterized by being equipped with the following features.

7. Let N and M be positive integers. The transmitting device has N rows of the transmitting linear array antennas as the plurality of transmitting antenna elements. The receiving device has M rows of receiving linear array antennas arranged orthogonally to the N rows of transmitting linear array antennas, with the plurality of receiving antenna elements being the receiving linear array antennas. The weighting processing unit applies a spatially weighted window function to the received signals of each virtual antenna element corresponding to the spatial position of the object being measured in the received image, which is divided into N × M cells corresponding to a virtual two-dimensional array element obtained by combining the array of the transmitting linear array antennas in N columns and the array of the receiving linear array antennas in M ​​columns, and performs the weighting processing. The receiving device according to feature 6.

8. Let N and M be set to 2. The transmitting device has two rows of the transmitting linear array antennas as the plurality of transmitting antenna elements. The receiving device has two rows of receiving linear array antennas as the plurality of receiving antenna elements, arranged orthogonally to the two rows of transmitting linear array antennas. The weighting processing unit applies the window function to the received signals of each virtual antenna element corresponding to the spatial position of the object to be measured in the received image, which is divided into 2x2 cells corresponding to a virtual two-dimensional array element obtained by combining the arrangement of two rows of the transmitting linear array antennas and the arrangement of two rows of the receiving linear array antennas, and performs the weighting processing. The receiving device according to feature 7.

9. A control circuit for controlling a sensing system, In a transmitting device, a transmitting array antenna is provided as a plurality of transmitting antenna elements, and the timing of generating a radar signal, generating a code for separating the high-frequency signals transmitted from the plurality of transmitting antenna elements into the high-frequency signals transmitted from each transmitting antenna element by a receiving device, and generating a carrier signal is controlled, the radar signal and the code are multiplied for each of the plurality of transmitting antenna elements, and the high-frequency signal is generated using the radar signal multiplied by the code and the carrier signal and transmitted from the plurality of transmitting antenna elements. In the receiving device, a receiving array antenna is provided as a plurality of receiving antenna elements to receive the high-frequency signal transmitted from the transmitting device and reflected or scattered by the object to be measured. Transmission path information indicating the state of the transmission path between the transmitting device and the receiving device is generated using the carrier signal, the radar signal, and the code. The position of the object to be measured is identified using the transmission path information. The received image obtained by performing focus correction on the object to be measured is weighted according to the spatial position of the object to be measured in the received image, and a fast Fourier transform is performed to generate an image of the object to be measured. A control circuit characterized by causing the sensing system to perform the above.

10. A control circuit for controlling a receiving device that receives reflected or scattered waves of a high-frequency signal transmitted from a transmitting device having a plurality of receiving linear array antennas as receiving antenna elements and a plurality of transmitting linear array antennas as transmitting antenna elements, and which is reflected or scattered by a target to be measured, The reflected or scattered waves of the high-frequency signal received by the multiple receiving antenna elements are converted into a received signal in the frequency band of the radar signal used to generate the high-frequency signal in the transmitting device, using the carrier signal used to generate the high-frequency signal in the transmitting device. The received signal is detected using the radar signal, and received information is obtained that includes the reflected or scattered waves of the high-frequency signal received by each receiving antenna element, and the high-frequency signal transmitted from a plurality of transmitting antenna elements. Correlation processing is performed on the received information using the code used when the radar signal was encoded by the transmitting device, and the received signal is separated into signals for each transmitting antenna element transmitted from the transmitting device for each receiving antenna element. Using the separated signals, generate transmission path information indicating the state of the transmission path between the transmitting device and the receiving device. Using the aforementioned transmission path information, the location of the object to be measured is identified. Focus correction of the measurement target whose position has been identified, Weighting processing is performed on the received signals of each virtual antenna element according to the spatial position of the object to be measured in the received image obtained by the focus correction. The received signals of each weighted virtual antenna element are subjected to a Fast Fourier Transform process to generate the image of the object to be measured. A control circuit characterized by causing the receiving device to perform the above.

11. A storage medium in which a program for controlling a sensing system is stored, The aforementioned program, In a transmitting device, a transmitting array antenna is provided as a plurality of transmitting antenna elements, and the timing of generating a radar signal, generating a code for separating the high-frequency signals transmitted from the plurality of transmitting antenna elements into the high-frequency signals transmitted from each transmitting antenna element by a receiving device, and generating a carrier signal is controlled, the radar signal and the code are multiplied for each of the plurality of transmitting antenna elements, and the high-frequency signal is generated using the radar signal multiplied by the code and the carrier signal and transmitted from the plurality of transmitting antenna elements. In the receiving device, a receiving array antenna is provided as a plurality of receiving antenna elements to receive the high-frequency signal transmitted from the transmitting device and reflected or scattered by the object to be measured. Transmission path information indicating the state of the transmission path between the transmitting device and the receiving device is generated using the carrier signal, the radar signal, and the code. The position of the object to be measured is identified using the transmission path information. The received image obtained by performing focus correction on the object to be measured is weighted according to the spatial position of the object to be measured in the received image, and a fast Fourier transform is performed to generate an image of the object to be measured. A storage medium characterized by having the sensing system perform the above.

12. A storage medium storing a program for controlling a receiving device that receives reflected or scattered waves of a high-frequency signal transmitted from a transmitting device having multiple receiving linear array antennas as receiving antenna elements and multiple transmitting linear array antennas as transmitting antenna elements, and which is reflected or scattered by a target for measurement, The aforementioned program, The reflected or scattered waves of the high-frequency signal received by the multiple receiving antenna elements are converted into a received signal in the frequency band of the radar signal used to generate the high-frequency signal in the transmitting device, using the carrier signal used to generate the high-frequency signal in the transmitting device. The received signal is detected using the radar signal, and received information is obtained that includes the reflected or scattered waves of the high-frequency signal received by each receiving antenna element, and the high-frequency signal transmitted from a plurality of transmitting antenna elements. Correlation processing is performed on the received information using the code used when the radar signal was encoded by the transmitting device, and the received signal is separated into signals for each transmitting antenna element transmitted from the transmitting device for each receiving antenna element. Using the separated signals, generate transmission path information indicating the state of the transmission path between the transmitting device and the receiving device. Using the aforementioned transmission path information, the location of the object to be measured is identified. Focus correction of the measurement target whose position has been identified, Weighting processing is performed on the received signals of each virtual antenna element according to the spatial position of the object to be measured in the received image obtained by the focus correction. The received signals of each weighted virtual antenna element are subjected to a Fast Fourier Transform process to generate the image of the object to be measured. A storage medium characterized by causing the receiving device to perform the above action.

13. A transmitting device has a transmitting array antenna as a plurality of transmitting antenna elements, and controls the timing of generating a radar signal, generating a code for a receiving device to separate the high-frequency signals transmitted from the plurality of transmitting antenna elements into the high-frequency signals transmitted from each transmitting antenna element, and generating a carrier signal, multiplying the radar signal and the code for each of the plurality of transmitting antenna elements, generating the high-frequency signal using the radar signal multiplied by the code and the carrier signal, and transmitting it from the plurality of transmitting antenna elements. The receiving device has a receiving array antenna as a plurality of receiving antenna elements and receives the high-frequency signal transmitted from the transmitting device and reflected or scattered by the object to be measured. Using the carrier signal, the radar signal, and the code, it generates transmission path information indicating the state of the transmission path between the transmitting device and the receiving device. Using the transmission path information, it identifies the position of the object to be measured. Focus correction of the object to be measured is performed, and the received signal of each virtual antenna element is weighted according to the spatial position of the object to be measured in the obtained received image. Fast Fourier transform processing is performed to generate an image of the object to be measured. A sensing method characterized by including

14. A receiving device for receiving reflected or scattered waves of a high-frequency signal transmitted from a transmitting device having a plurality of receiving linear array antennas as receiving antenna elements and a plurality of transmitting linear array antennas as transmitting antenna elements, wherein the receiving device receives reflected or scattered waves of a high-frequency signal that has been reflected or scattered by a target to be measured. The signal conversion unit performs a signal conversion step in which it converts the reflected or scattered waves of the high-frequency signal received by a plurality of receiving antenna elements into a received signal in the frequency band of the radar signal used to generate the high-frequency signal in the transmitting device, using the carrier signal used to generate the high-frequency signal in the transmitting device. The detection unit detects the received signal using the radar signal and obtains received information which includes the reflected or scattered waves of the high-frequency signal received by each receiving antenna element and the high-frequency signal transmitted from a plurality of transmitting antenna elements. The correlation processing unit performs correlation processing on the received information using the code used when the radar signal was encoded by the transmitting device, and separates the received signal into signals for each transmitting antenna element transmitted from the transmitting device for each receiving antenna element, in a correlation processing step. A transmission path regeneration step in which the transmission path regeneration unit generates transmission path information indicating the state of the transmission path between the transmitting device and the receiving device using the separated signals, The layer extraction unit performs a layer extraction step that uses the transmission path information to identify the position of the object to be measured, The focus correction unit performs a focus correction step that corrects the focus of the measurement target whose position has been identified, A weighting processing step in which the weighting processing unit performs weighting processing on the received signals of each virtual antenna element according to the spatial position of the object to be measured in the received image obtained by the focus correction unit, A Fast Fourier Transform processing step in which a Fast Fourier Transform processing unit performs Fast Fourier Transform processing on the received signals of each virtual antenna element weighted by the weighting processing unit to generate an image of the object to be measured, A receiving method characterized by including the following.