LFM signal ranging error correction method, device, equipment, medium and program product

Abstract

The invention relates to the technical field of radar ranging, and provides an LFM signal ranging error correction method, device and equipment, a medium and a program product, and the method comprises the steps: measuring the apparent distance and the apparent speed of a target; resolving target speed blurring based on the target apparent distance and the apparent speed to obtain the real speed of the target; estimating target distance offset by using the real speed of the target; correcting the target apparent distance by using the target distance offset; and resolving target distance ambiguity by using the corrected target apparent distance to obtain a target real distance. The method is combined with speed ambiguity and distance ambiguity resolving after radar CFAR, target speed estimation and distance correction are achieved, extra data processing does not need to be carried out on sampled intermediate frequency signals, extra detection waveforms are not adopted, and the method is suitable for multiple high-speed moving targets at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of radar ranging, and in particular, to a method, device, equipment, medium and program product for correcting ranging errors of LFM signals. Background Art

[0002] Due to the range-Doppler coupling characteristic, linear frequency modulation (LFM) signals will generate a range shift proportional to the Doppler frequency during pulse compression, resulting in ranging errors. The higher the target speed, the greater the ranging error, and error correction is required to improve the target ranging accuracy.

[0003] Existing methods for correcting range-Doppler coupling errors include: positive and negative frequency modulation method, track filtering to estimate speed method, speed ambiguity resolution method, etc. The positive and negative frequency modulation method uses positive and negative frequency modulation waveforms to detect targets, which will reduce the effective data rate of the radar by half and is limited in engineering applications; the track filtering method estimates the target speed based on the range difference after track filtering. However, the ranging error itself will affect the accuracy of track filtering, and the data interval of track filtering is in the order of hundreds of milliseconds, resulting in large filtering errors due to high-speed maneuvering of the target; the speed ambiguity resolution method uses a waterfall plot to solve the target speed ambiguity, which requires segmented spectrum calculation of intermediate frequency data, has a large amount of computation, and is not applicable to the case of multiple targets.

[0004] In addition, for multiple targets moving at high speeds, correcting the range errors caused by different Doppler frequencies also faces the following problems: Doppler frequency estimation requires multi-target matching, and the phase correction before pulse compression is not suitable for multiple targets, etc. At present, no relevant literature or patents have given solutions to the above problems. Summary of the Invention

[0005] The present invention aims to provide a method, device, equipment, medium and program product for correcting ranging errors of LFM signals to solve the ranging error problem when the radar LFM signal detects multiple high-speed moving targets.

[0006] In a first aspect, the present invention provides a method for correcting ranging errors of LFM signals, including:

[0007] Measuring the apparent distance and apparent speed of the target;

[0008] Solving the speed ambiguity of the target based on the apparent distance and apparent speed of the target to obtain the true speed of the target;

[0009] Estimating the target range shift using the true speed of the target;

[0010] Correcting the apparent distance of the target using the target range shift;

[0011] Using the corrected apparent target distance, resolve the target distance ambiguity to obtain the true target distance.

[0012] In some embodiments, the measuring the apparent target distance and apparent speed includes:

[0013] Transmit M groups of LFM signals with different pulse repetition frequencies to detect a moving target, process the target echo corresponding to each group of pulse repetition frequencies, condense the processed original traces in the range dimension and velocity dimension to obtain the apparent distance and apparent speed; wherein, processing the target echo includes pulse compression, inter-pulse coherence, and constant false alarm rate detection.

[0014] In some embodiments, the resolving the target speed ambiguity based on the apparent target distance and apparent speed includes:

[0015] Select N groups from the M groups of pulse repetition frequencies for multi-target matching and de-ambiguity; sequentially select one target data from the N groups of pulse repetition frequencies, and use the least squares method to resolve the target speed ambiguity; based on the apparent speed V ij and apparent distance R ij of the jth target in the ith group of pulse repetition frequencies, calculate all possible speeds corresponding to the apparent speed V ij , expressed as:

[0016]

[0017] wherein, V max is the maximum detection speed of the radar, V i,u = 1 / PRI i ·λ / 2 is the unambiguous speed corresponding to the PRI i of the ith group of pulse repetition frequencies, λ is the wavelength of the radar signal, represents rounding up;

[0018] After calculating all possible speeds of the selected data in the N groups of pulse repetition frequencies, arrange the obtained values in ascending order to obtain a one-dimensional array V o , calculate the mean square error C o of adjacent N elements of this one-dimensional array V V (j):

[0019]

[0020] wherein, is the mean of adjacent N values in the one-dimensional array V o ;

[0021] If the minimum mean square error C V,min is less than the set first threshold T V , it is considered that the target speed matching under different pulse repetition frequencies is successful, and the corresponding mean value is the true target speed;

[0022] If the minimum mean square error C V,min is greater than the set first threshold T V , it is considered that the target matching is unsuccessful, and the next data is selected to solve the target velocity ambiguity by the least squares method.

[0023] In some embodiments, estimating the target distance offset using the target true velocity includes:

[0024] Using the target true velocity to estimate the target Doppler frequency shift f d , expressed as:

[0025]

[0026] Using the estimated target Doppler frequency shift to estimate the target distance offset Δr, expressed as:

[0027] Δr = f d / κ·c / 2

[0028] where κ = B / τ represents the frequency modulation slope of the LFM signal, B is the signal bandwidth, and τ is the signal pulse width.

[0029] In some embodiments, correcting the target apparent distance using the target distance offset includes:

[0030] Subtracting the target distance offset from the target apparent distance to obtain the corrected target apparent distance; where, for the jth target apparent distance R in the ith group of pulse repetition frequencies ij , the corrected target apparent distance R ij,c is expressed as: R ij,c = R ij -Δr.

[0031] In some embodiments, resolving the target distance ambiguity using the corrected target apparent distance includes:

[0032] Performing distance ambiguity resolution on the corrected target apparent distance using the least squares method,

[0033] Calculating all possible distances corresponding to the corrected target apparent distance R ij,c as:

[0034]

[0035] where, R max is the maximum detection distance of the radar, R i,u = PRI i ·c / 2 is the unambiguous distance corresponding to the ith group of pulse repetition frequencies PRI i , denotes rounding up, and c is the speed of light;

[0036] After calculating all possible distances of the data with successful speed matching in N pulse repetition frequencies, the obtained values are sorted in ascending order to obtain a one-dimensional array R o , calculate this one-dimensional array R o The mean square error C R (j) of adjacent N elements:

[0037]

[0038] where, is the mean value of adjacent N numerical values in the one-dimensional array R o ;

[0039] If the minimum mean square error C R,min is less than the set second threshold T R , it is considered that the target distance matching is successful under different pulse repetition frequencies, and the corresponding mean value is the true distance of the target;

[0040] If the minimum mean square error C R,min is greater than the set second threshold T R , it is considered that the target distance matching is unsuccessful, and the target speed ambiguity and target distance ambiguity are resolved again.

[0041] In a second aspect, the present invention provides an LFM signal ranging error correction device, including

[0042] A first processing unit for measuring the apparent distance and apparent speed of the target;

[0043] A second processing unit for resolving the target speed ambiguity based on the apparent distance and apparent speed of the target to obtain the true speed of the target;

[0044] A third processing unit for estimating the target distance offset by using the true speed of the target;

[0045] A fourth processing unit for correcting the apparent distance of the target by using the target distance offset;

[0046] A fifth processing unit for resolving the target distance ambiguity by using the corrected apparent distance of the target to obtain the true distance of the target.

[0047] In a third aspect, the present invention provides an electronic device, including:

[0048] At least one processor; and a memory communicatively connected to the at least one processor;

[0049] wherein, the memory stores instructions executable by the at least one processor, and the at least one processor, by executing the instructions stored in the memory, causes the at least one processor to execute the described method.

[0050] Fourthly, the present invention provides a computer-readable storage medium for storing instructions which, when executed, implement the above-mentioned method.

[0051] Fifthly, the present invention provides a computer program product which, when called by a computer, causes the computer to execute the above-mentioned method.

[0052] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0053] Aiming at the ranging error problem of detecting multiple high-speed moving targets by radar LFM signals, the present invention proposes a method for correcting the ranging error of LFM signals. This method first measures the apparent distance and apparent speed after CFAR, uses the least squares method to solve the unambiguous true speed of the target, estimates the target distance offset according to the true speed of the target, then corrects the apparent distance of the target using the distance offset, and finally resolves the target distance ambiguity to obtain the true distance and true speed of the target. This method combines with the speed ambiguity and distance ambiguity resolution after radar CFAR to realize target speed estimation and distance correction, without performing additional data processing on the sampled intermediate frequency signals, without using additional detection waveforms, and is applicable to multiple high-speed moving targets at the same time. The implementation examples show that the greater the relative motion speed between the target and the radar, the greater the ranging error of the traditional measurement method. After adopting the distance correction method proposed by the present invention, the ranging error is within the measurement accuracy range of the radar system. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a flowchart of a method for correcting the ranging error of LFM signals proposed in an embodiment of the present invention.

[0055] Figure 2a It is a diagram showing the CFAR detection results corresponding to the first set of pulse repetition frequencies in an example of an embodiment of the present invention.

[0056] Figure 2b It is a diagram showing the CFAR detection results corresponding to the first set of pulse repetition frequencies in an example of an embodiment of the present invention.

[0057] Figure 2c It is a diagram showing the CFAR detection results corresponding to the first set of pulse repetition frequencies in an example of an embodiment of the present invention.

[0058] Figure 2d It is a diagram showing the CFAR detection results corresponding to the first set of pulse repetition frequencies in an example of an embodiment of the present invention.

[0059] Figure 3 It is a diagram showing the target distances measured by different methods.

[0060] Figure 4 Schematic diagram of a device for correcting ranging error of LFM signals proposed in an embodiment of the present invention.

[0061] Figure 5 Schematic diagram of an electronic device proposed in an embodiment of the present invention. Detailed implementation manners

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated herein can be arranged and designed in various different configurations.

[0063] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0064] As Figure 1 shown, an embodiment of the present invention proposes an LFM signal ranging error correction method, including the following steps:

[0065] Step S1, measure the apparent distance and apparent speed of the target.

[0066] In some embodiments, step S1 includes: transmitting M groups of LFM signals with different repetition frequencies to detect a moving target, processing the target echo corresponding to each repetition frequency, and aggregating the processed original traces in the range dimension and speed dimension to obtain the apparent distance and apparent speed. Among them, processing the target echo includes pulse compression, inter-pulse coherence, constant false alarm rate (CFAR) detection, etc.

[0067] Step S2, based on the apparent distance and apparent speed of the target, resolve the target speed ambiguity to obtain the true speed of the target.

[0068] Select N groups from the M groups of repetition frequencies for multi-target matching and ambiguity resolution, with a total of combinations. In some embodiments, step S2 includes the following sub-steps:

[0069] Step S21, sequentially select 1 target data from each group of repetition frequencies, and use the least squares method to resolve the target speed ambiguity;

[0070] Step S22, based on the apparent speed V of the jth target in the ith group of repetition frequencies ijand the apparent distance R ij , calculate the apparent speed V ij All possible speeds corresponding to are expressed as:

[0071]

[0072] where V max is the maximum detection speed of the radar, V i,u = 1 / PRI i ·λ / 2 is the unambiguous speed corresponding to the i-th group of pulse repetition intervals PRI i , λ is the radar signal wavelength, represents rounding up.

[0073] Step S23, after calculating all possible speeds of the selected data in N groups of pulse repetition intervals, arrange the obtained values in ascending order to obtain a one-dimensional array V o , calculate the mean square error C o of adjacent N elements of this one-dimensional array V V (j):

[0074]

[0075] where is the mean of adjacent N values in the one-dimensional array V o .

[0076] Step S24, find the minimum mean square error C V,min :

[0077] If the minimum mean square error C V,min is less than the set first threshold T V , it is considered that the target speeds under different pulse repetition intervals match successfully, and the corresponding mean is the true target speed;

[0078] If the minimum mean square error C V,min is greater than the set first threshold T V , it is considered that the target matching is unsuccessful, select the next data, and repeat steps S21 to S24.

[0079] Step S3, use the true target speed to estimate the target distance offset.

[0080] Step S31, use the true target speed to estimate the target Doppler frequency shift f d , which is expressed as:

[0081]

[0082] Step S32: Estimate the target range offset by using the estimated target Doppler shift, which is expressed as:

[0083] Δr = f d / κ·c / 2 (4)

[0084] where κ = B / τ represents the frequency modulation slope of the LFM signal, B is the signal bandwidth, and τ is the signal pulse width. It can be seen that the target range offset can be calculated as:

[0085]

[0086] Step S4: Use the target range offset to correct the target apparent range.

[0087] For the target data after successful velocity matching, correct the apparent range R of the j-th target in the i-th PRF by using Equation (5). ij The corrected target apparent range R ij,c is expressed as:

[0088] R ij,c = R ij -Δr (6)

[0089] Step S5: Use the corrected target apparent range to resolve the target range ambiguity and obtain the target true range.

[0090] In some embodiments, Step S5 includes the following sub-steps:

[0091] Step S51: Use the least squares method to perform range ambiguity resolution on the corrected target apparent range, and calculate all possible ranges corresponding to the corrected target apparent range R ij,c as:

[0092]

[0093] where R max is the maximum detection range of the radar, R i,u = PRI i ·c / 2 is the unambiguous range corresponding to the i-th PRF i , denotes rounding up, and c is the speed of light.

[0094] Step S52: After calculating all possible ranges of the data with successful velocity matching in N PRFs, arrange the obtained values in ascending order to obtain a one-dimensional array R o , and calculate the mean square error C o of adjacent N elements of this one-dimensional array R R (j):

[0095]

[0096] wherein, is the average value of N adjacent numerical values in the one-dimensional array R o in

[0097] Step S53, calculate the minimum mean square error C R,min :

[0098] If the minimum mean square error C R,min is less than the set second threshold T R , it is considered that the target distance matching is successful at different pulse repetition frequencies, and the corresponding average value is the true distance of the target, and output the true distance of the target and the true speed of the target

[0099] If the minimum mean square error C R,min is greater than the set second threshold T R , it is considered that the target distance matching is unsuccessful, and repeat steps S2 to S5.

[0100] To verify the performance of the correction method proposed by the present invention, 4 moving targets are set up for radar signal processing simulation. Assume that the distances of the 4 targets from the radar are 100 km, 101 km, 102 km, and 103 km respectively, and the relative moving speeds with the radar platform are 1000 m / s, -500 m / s, 800 m / s, and -300 m / s respectively. The radar signal wavelength is 0.01 m, the pulse width is 20 us, and the bandwidth is 2 MHz.

[0101] According to the implementation process shown in Figure 1 , the implementation steps of this example are as follows:

[0102] Step S1, measure the apparent distance and apparent speed of the target.

[0103] Transmit 4 groups of LFM signals with different pulse repetition frequencies to detect moving targets. The pulse repetition intervals (PRIs) are 211 us, 229 us, 241 us, and 257 us respectively. Pulse compression, inter-pulse coherence, constant false alarm rate (CFAR) detection, etc. are performed on the target echoes corresponding to each pulse repetition frequency. The original traces after processing are condensed in the distance dimension and speed dimension to obtain the apparent distance and apparent speed. The CFAR detection results corresponding to the 4 pulse repetition frequencies are as shown in Figure 2a , Figure 2b , Figure 2c , Figure 2d . In the second pulse repetition frequency, there are only 3 targets because one of the targets is in the radar blind area. The condensed apparent distances and apparent Doppler frequencies (apparent speed × wavelength / 2) are shown in Table 1 respectively.

[0104] Table 1, Apparent Distance and Apparent Doppler Frequency after Coagulation:

[0105]

[0106] Step S2, resolve the target velocity ambiguity based on the target apparent distance and apparent velocity to obtain the target true velocity.

[0107] Select 3 groups of PRIs from 4 groups of pulse repetition frequencies for ambiguity resolution. There are 4 combinations in total. Select one data from each group of PRIs and use the least squares method to resolve the velocity ambiguity. When the minimum mean square error is less than the velocity measurement accuracy of the radar system, it is considered that the target velocity matching is successful, and the obtained target true velocity is 999.996 m / s.

[0108] Step S3, estimate the target distance offset using the target true velocity.

[0109] Estimate the target Doppler shift to be 200 kHz according to the resolved target true velocity. The target distance deviation caused by the target Doppler shift is 299.999 m.

[0110] Step S4, correct the target apparent distance using the target distance offset.

[0111] For the target data after successful velocity matching, correct its apparent distance using the estimated target distance deviation.

[0112] Step S5, resolve the target distance ambiguity using the corrected target apparent distance to obtain the target true distance.

[0113] For the target data after successful velocity matching and corrected apparent distance, use the least squares method to resolve the target distance ambiguity. When the minimum mean square error is less than the ranging accuracy of the radar system, it is considered that the target distance also matches successfully, and output the target true distance as 99997 m.

[0114] After traversing all target data combinations and pulse repetition frequency combinations, the measured distances of 4 targets are 99997 m, 100988 m, 101981 m, and 102995 m respectively.

[0115] To evaluate the ranging performance of this method, 50 Monte Carlo tests are carried out. In each test, the ranging error and velocity measurement error of the radar system itself are randomly generated and reflected in the apparent distance and apparent velocity of the test data. The distance measurement results of the traditional method and the method described in this patent are as Figure 3 shown. It can be seen that the ranging error of the method of the present invention is much smaller than that of the traditional method within the measurement accuracy range of the radar system.

[0116] Based on the same technical concept, as Figure 4As shown in the figure, an embodiment of the present invention further provides an LFM signal ranging error correction device, which is characterized by including

[0117] A first processing unit for measuring the target apparent distance and apparent speed;

[0118] A second processing unit for resolving the target speed ambiguity based on the target apparent distance and apparent speed to obtain the target true speed;

[0119] A third processing unit for estimating the target distance offset by using the target true speed;

[0120] A fourth processing unit for correcting the target apparent distance by using the target distance offset;

[0121] A fifth processing unit for resolving the target distance ambiguity by using the corrected target apparent distance to obtain the target true distance.

[0122] As for the specific processing methods of each processing unit in the above device, reference may be made to the specific description of the above method, which will not be elaborated here.

[0123] Based on the same technical concept, an embodiment of the present invention further provides a radar target simulation system, in which the above-mentioned target high-resolution range profile echo simulation device is provided. The working principle of the target high-resolution range profile echo simulation device may be referred to the specific description of the above method, which will not be elaborated here.

[0124] Based on the same technical concept, an embodiment of the present invention further provides an electronic device, which can implement the LFM signal ranging error correction method flow provided in the above embodiment of the present invention. In one embodiment, the electronic device may be a server, or a terminal device or other electronic devices. As Figure 5 shown, the electronic device may include:

[0125] At least one processor, and a memory connected to at least one processor. In the embodiment of the present invention, the specific connection medium between the processor and the memory is not limited. Figure 5 In the example, it is assumed that the processor and the memory are connected by a bus. The bus is Figure 5 shown as a thick line in the figure. The connection methods between other components are only for illustrative purposes and are not to be construed as limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, Figure 5 only a thick line is shown in the figure, but it does not mean that there is only one bus or one type of bus. Alternatively, the processor may also be referred to as a controller, and no limitation is imposed on the name.

[0126] In an embodiment of the present invention, a memory stores instructions executable by at least one processor. By executing the instructions stored in the memory, the at least one processor can execute a method for correcting the ranging error of an LFM signal as described above. The processor can implement Figure 5 the functions of each module in the device shown.

[0127] Among them, the processor is the control center of the device. It can connect various parts of the entire control device through various interfaces and lines. By running or executing the instructions stored in the memory and calling the data stored in the memory, various functions of the device and process data, thereby monitoring the device as a whole.

[0128] In an alternative design, the processor may include one or more processing units. The processor may integrate an application processor and a modem processor. Among them, the application processor mainly processes the operating system, user interface, application programs, etc., and the modem processor mainly processes wireless communication. It can be understood that the above-mentioned modem processor may not be integrated into the processor. In some embodiments, the processor and the memory may be implemented on the same chip. In some embodiments, they may also be separately implemented on independent chips.

[0129] The processor may be a general-purpose processor, such as a CPU, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of a method for correcting the ranging error of an LFM signal disclosed in combination with the embodiments of the present invention can be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0130] As a non-volatile computer-readable storage medium, the memory can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The memory may include at least one type of storage medium, for example, it may include flash memory, hard disk, multimedia card, card-type memory, random access memory (RAM), static random access memory (SRAM), programmable read-only memory (PROM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic memory, magnetic disk, optical disc, and so on. The memory is any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory in the embodiments of the present invention may also be a circuit or any other device capable of implementing a storage function, for storing program instructions and / or data.

[0131] By designing and programming the processor, the code corresponding to the method for correcting the ranging error of an LFM signal introduced in the foregoing embodiments can be solidified into the chip, so that the chip can execute the steps of the method in the foregoing embodiments when running. How to design and program the processor is a well-known technology to those skilled in the art and will not be elaborated here.

[0132] Based on the same inventive concept, the embodiments of the present invention also provide a storage medium storing computer instructions, which when run on a computer, cause the computer to execute a method for correcting the ranging error of an LFM signal discussed above.

[0133] In some optional embodiments, the various aspects of the method for correcting the ranging error of an LFM signal of the present invention can also be implemented in the form of a program product, which includes program code that, when the program product runs on a device, causes the control device to execute the steps in a method for correcting the ranging error of an LFM signal according to various exemplary embodiments of the present invention described above in this specification.

[0134] It should be noted that although several units or subunits of the device are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to the embodiments of the present invention, the features and functions of two or more of the above-described units can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units. In addition, although the operations of the method of the present invention are described in a specific order in the drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution.

[0135] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0136] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a server, such that the instructions executed by the processor of the computer or other programmable data processing device generate means for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0137] Program code for performing the operations of the present invention can be written using any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, etc., and also including conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, executed as an independent software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0138] In the case of a remote computing device, the remote computing device may be connected to the user computing device via any kind of network including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., by using an Internet service provider to connect via the Internet).

[0139] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction device that implements the functions specified in one process Figure 1 or a plurality of processes and / or blocks Figure 1 or a plurality of blocks specified in one block or a plurality of blocks.

[0140] These computer program instructions may also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are performed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one process Figure 1 or a plurality of processes and / or blocks Figure 1 or a plurality of blocks specified in one block or a plurality of blocks.

[0141] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for correcting LFM signal ranging errors, characterized in that: include: Measure the apparent distance and apparent speed of the target; The target velocity ambiguity is resolved based on the target apparent distance and apparent velocity to obtain the target true velocity; Using the target true speed, estimating the target range offset; Correcting the target apparent distance using the target distance offset; The corrected target apparent distance is used to resolve the target distance ambiguity and obtain the target's true distance.

2. The LFM signal ranging error correction method according to claim 1, characterized in that: The measuring target apparent distance and apparent speed include: M groups of LFM signals with different repetition rates are emitted to detect moving targets, and the target echo corresponding to each group of repetition rates is processed. The processed original points are condensed in the distance dimension and the speed dimension to obtain the apparent distance and the apparent speed. The processing of the target echo includes pulse compression, pulse coherence, and constant false alarm detection.

3. The LFM signal ranging error correction method according to claim 2, characterized in that: The method of resolving target speed ambiguity based on target apparent distance and apparent speed includes: Select N groups from M groups of repetitions for multi-target matching and defuzzification; select one target data from N groups of repetitions in turn, and use the least squares method to resolve the target speed fuzziness; based on the apparent speed V of the jth target in the i-th group of repetitions ij and the apparent distance R ij , calculate the apparent speed V ij The corresponding possible speeds are expressed as: Among them, V max is the maximum detection speed of the radar, V i,u =1 / PRI i ·λ2 is the repetition rate PRI of the i-th group i The corresponding unambiguous speed, λ is the wavelength of the radar signal, Indicates rounding up; After calculating all possible speeds of the selected data in N groups of repetition frequencies, the obtained values ​​are arranged in ascending order to obtain a one-dimensional array V o , calculate the one-dimensional array V o The mean square error C of N adjacent elements V (j): in, is a one-dimensional array V o The mean of the N adjacent values ​​in ; If the minimum mean square error C V,min Less than the first threshold T V , then it is considered that the target speeds at different repetition frequencies are matched successfully, and the corresponding mean is the target true speed; If the minimum mean square error C V,min Greater than the first threshold T V , it is considered that the target matching is unsuccessful, and the next data is selected to use the least squares method to resolve the target speed ambiguity.

4. The LFM signal ranging error correction method according to claim 3, characterized in that: Using the target true speed, estimating the target distance offset includes: Using the target true speed Estimate the target Doppler shift f d , expressed as: Using the estimated target Doppler shift, the target range offset Δr is estimated, which is expressed as: Δr=f d / k·c / 2 Wherein, κ=B / τ represents the frequency modulation slope of the LFM signal, B is the signal bandwidth, and τ is the signal pulse width.

5. The LFM signal ranging error correction method according to claim 4, characterized in that: Using the target distance offset, correcting the target apparent distance includes: Subtract the target distance offset from the target apparent distance to obtain the corrected target apparent distance; where the apparent distance R of the jth target in the i-th group of repetitions is ij , the corrected target apparent distance R ij,c Expressed as: R ij,c =R ij -Δr.

6. The LFM signal ranging error correction method according to claim 5, characterized in that: Using the corrected target apparent distance, resolve the target distance ambiguity, including: The least square method is used to resolve the distance ambiguity of the corrected target apparent distance. Calculate the corrected target apparent distance R ij,c The corresponding possible distances are: Among them, R max is the maximum detection distance of the radar, R i,u =PRI i c / 2 is the PRI of the i-th group i The corresponding unambiguous distance, means rounding up, c is the speed of light; After calculating all possible distances of the data with successful speed matching in N groups of repetitions, the obtained values ​​are arranged in ascending order to obtain a one-dimensional array R o , calculate the one-dimensional array R o The mean square error C of N adjacent elements R (j): in, is a one-dimensional array R o The mean of the N adjacent values ​​in ; If the minimum mean square error C R,min Less than the set second threshold T R , then it is considered that the target distances at different repetition frequencies are matched successfully, and the corresponding mean is the true distance of the target; If the minimum mean square error C R,min Greater than the set second threshold T R , the target distance matching is considered unsuccessful, and the target velocity ambiguity and target distance ambiguity are recalculated.

7. A LFM signal ranging error correction device, characterized in that: include A first processing unit is used to measure the apparent distance and apparent speed of the target; A second processing unit is used to resolve the target speed ambiguity based on the target apparent distance and apparent speed to obtain the target real speed; A third processing unit, configured to estimate a target distance offset using the target true speed; A fourth processing unit, configured to correct the target apparent distance using the target distance offset; The fifth processing unit is used to use the corrected target apparent distance to resolve the target distance ambiguity and obtain the target real distance.

8. An electronic device, characterized in that: include: at least one processor; and a memory communicatively coupled to the at least one processor; The memory stores instructions that can be executed by the at least one processor, and the at least one processor executes the method as described in any one of claims 1 to 6 by executing the instructions stored in the memory.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store instructions, and when the instructions are executed, the method according to any one of claims 1 to 6 is implemented.

10. A computer program product, characterized in that When the computer program product is called by a computer, the computer executes the method according to any one of claims 1 to 6.

Images