A cordic fault-tolerant method and apparatus for sar imaging angle computation

Abstract

The application discloses a CORDIC fault-tolerant method and device for SAR imaging angle calculation. The method comprises the following steps: S101, acquiring original SAR angle information; S102, performing iterative processing on the original SAR angle information to obtain a first output result; S103, performing redundancy fault-tolerant processing based on error correction coding based on the original SAR angle information to obtain a second output result; S104, performing error detection and positioning processing based on the first output result and the second output result, if there is no error, returning the first output result as a final result to a user, and if there is an error, performing S105; S105, performing error correction processing on the first output result based on the second output result, and returning the first output result after error correction as a final result to the user. Through the technical scheme of the application, the reliability of a SAR imaging system can be improved, and fault-tolerant resource consumption can be reduced.

Description

Technical Field

[0001] This invention relates to the field of SAR image processing technology, and specifically to a CORDIC fault-tolerant method and apparatus for SAR imaging angle calculation. Background Technology

[0002] SAR imaging is a technique that uses synthetic aperture radar (SAR) to image targets. As an important radar imaging technology, SAR imaging has been widely used in military and civilian fields. In SAR imaging, the CORDIC (Coordinate Rotation Digital Computer) algorithm is widely used to calculate angular information such as vector rotation to achieve efficient image processing. Due to the high reliability requirements of SAR imaging, the fault-tolerant design requirements for SAR image processors are also very high. Traditional fault-tolerant techniques often increase design costs and reduce system performance, failing to meet the needs of practical applications. Therefore, it is necessary to develop a new fault-tolerant method that can achieve high-performance SAR image processing under high reliability requirements.

[0003] Figure 1 This is a diagram of a granular pipelined CORDIC processor architecture without fault-tolerant hardening in existing technologies. Figure 1 As shown, existing CORDIC processors have M iteration units (M is at least 4). If any iteration unit fails, the result of the CORDIC operation will be incorrect. Therefore, existing CORDIC processors lack fault-tolerance mechanisms to protect the entire computation process. Traditional redundancy methods, such as triple modular redundancy, incur huge resource overhead. Therefore, it is necessary to design appropriate fault-tolerance methods based on their structural characteristics and algorithm features to provide good protection while reducing resource overhead. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a CORDIC fault-tolerant method and apparatus for SAR imaging angle calculation, which enables high-performance SAR image processing under high reliability requirements.

[0005] To achieve the objectives of this invention, the following technical solution is adopted:

[0006] A first aspect of the present invention provides a CORDIC fault-tolerant method for SAR imaging angle calculation, the method comprising: S101: acquiring original SAR angle information; S102: performing iterative processing using the original SAR angle information to obtain a first output result, wherein the first output result is SAR angle information after transcendence operation; the transcendence operation includes iterative processing repeated at least four times; S103: performing redundant fault-tolerant processing based on error correction coding based on the original SAR angle information to obtain a second output result, wherein the second output result is SAR angle information after fault-tolerant backup transcendence operation; S104: performing error detection and location processing based on the first output result and the second output result; if there is no error, returning the first output result as the final result to the user; if there is an error, executing S105; S105: performing error correction processing on the first output result based on the second output result, and returning the first output result after error correction as the final result to the user.

[0007] Furthermore, the original SAR angle information includes at least a phase factor.

[0008] Furthermore, the iterative processing using the original SAR angle information to obtain the first output result includes: performing N iterative processing on the original SAR angle information, wherein the iterative processing is based on the CORDIC algorithm, and its calculation method is as follows:

[0009]

[0010] Here, x and y are input parameters in the CORDIC algorithm, where x represents one component of the input angle or coordinate, y represents another component of the input angle or coordinate, z represents an intermediate variable used in the CORDIC algorithm for auxiliary calculations, m represents the coordinate system, and δ... i Indicates the direction of rotation, θ i The value represents the rotation angle, and N represents the number of iterations.

[0011] The rotation angle θ i The definition is as follows:

[0012]

[0013] When m=1, it represents a circular system; when m=0, it represents a linear system; when m=-1, it represents a hyperbolic system. By setting different values ​​of m, the CORDIC algorithm can be applied to handle different types of mathematical operations and geometric transformations.

[0014] The rotation direction δ i The definition is as follows:

[0015]

[0016] Further, the redundant fault-tolerant processing based on error correction coding based on the original SAR angle information to obtain the second output result includes: S103.1, linearly encoding the input data and the input data of the first N-1 iterations to obtain the encoded data; S103.2: performing the iteration processing on the encoded data once to obtain the second output result for error correction processing.

[0017] Furthermore, the error detection and localization processing based on the first output result and the second output result includes: using Hamming SEC encoding to implement error detection and localization.

[0018] A second aspect of the present invention provides a CORDIC fault-tolerant device for SAR imaging angle calculation, the device comprising: an acquisition module for acquiring raw SAR angle information; an iteration module connected to the acquisition module for performing iterative processing using the raw SAR angle information to obtain a first output result, wherein the first output result is SAR angle information after transcendence operation, the transcendence operation including iterative processing repeated at least four times; an error correction precoding module connected to the iteration module for performing redundant fault-tolerant processing based on error correction coding based on the raw SAR angle information, so that the first output result can be subsequently corrected based on a second output result; a fault-tolerant module connected to the error correction precoding module for obtaining a second output result through iterative calculation, wherein the second output result is SAR angle information after fault-tolerant backup transcendence operation; and an error detection and location correction module connected to the fault-tolerant module for performing error detection and location processing based on the first output result and the second output result. If there is no error, the first output result is returned to the user as the final result; if there is an error, error correction is performed, and the first output result after error correction is returned to the user as the final result.

[0019] Furthermore, the original SAR angle information includes at least a phase factor.

[0020] Furthermore, the iterative module is also used to: perform N iterative processing on the original SAR angle information, the iterative processing being implemented based on the CORDIC algorithm, and its calculation method is as follows:

[0021]

[0022] Here, x and y are input parameters in the CORDIC algorithm, where x represents one component of the input angle or coordinate, y represents another component of the input angle or coordinate, z represents the result in the CORDIC algorithm, m represents the coordinate system, and δ... i Indicates the direction of rotation, θ iThe value represents the rotation angle, and N represents the number of iterations.

[0023] The rotation angle θ i The definition is as follows:

[0024]

[0025] When m=1, it represents a circular system; when m=0, it represents a linear system; when m=-1, it represents a hyperbolic system. By setting different values ​​of m, the CORDIC algorithm can be applied to handle different types of mathematical operations and geometric transformations.

[0026] The rotation direction δ i The definition is as follows:

[0027]

[0028] Furthermore, the error correction precoding module further includes: an encoding unit, which performs linear encoding on the input data and the input data processed in the first N-1 iterations to obtain encoded data; and a fault tolerance calculation unit, which performs the iterative processing on the encoded data once to obtain a second output result for error correction processing.

[0029] Furthermore, the error detection and localization module is also used to: implement error detection and localization using Hamming SEC encoding.

[0030] This invention provides a CORDIC fault-tolerant method and apparatus for SAR imaging angle calculation, enabling high-performance SAR imaging phase factor generation under high reliability requirements. The solution employs error-correcting coding technology to achieve fault tolerance within a granular pipeline architecture, providing stronger protection with lower resource overhead and solving the problems of increased design costs and reduced system performance associated with traditional fault-tolerant techniques. Attached Figure Description

[0031] The above and other features, advantages, and aspects of the various embodiments of the present invention will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0032] Figure 1 This is a diagram of the existing granular pipelined CORDIC processor architecture without fault-tolerant hardening.

[0033] Figure 2 This is a flowchart of the method of the present invention;

[0034] Figure 3 This is a block diagram of the device of the present invention;

[0035] Figure 4 This is another embodiment of the device architecture diagram of the present invention;

[0036] Figure 5 This is a structural diagram of the iterative module of the present invention;

[0037] Figure 6 This is a schematic diagram illustrating the encoding method and error location of the error detection and localization module of the present invention. Detailed Implementation

[0038] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the invention. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention.

[0039] In the description of embodiments of the present invention, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The term "some embodiments" should be understood as "at least some embodiments". Other explicit and implicit definitions may also be included below.

[0040] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and descriptions are considered exemplary in nature and not restrictive. There is no requirement for the order of the method steps described, as long as they are achievable, they are within the scope of protection of this invention.

[0041] According to one aspect of the invention, such as Figure 2 As shown, a CORDIC fault-tolerant method for SAR imaging angle calculation is provided, the method comprising:

[0042] S101, obtain the raw SAR angle information.

[0043] The original SAR angle information includes at least the phase factor.

[0044] S102, the original SAR angle information is used for iterative processing to obtain a first output result, which is the SAR angle information after transcendental operation.

[0045] The transcendence operation includes at least four iterations. In some embodiments, a single transcendence operation may be repeated 16, 32, or 64 times (multiples of 4), etc., without limitation. As long as the number of iterations can achieve the purpose of this invention, it is within the scope of protection of this invention.

[0046] This step specifically includes the following steps:

[0047] The original SAR angle information is processed N times through iteration. This iteration is based on the CORDIC algorithm, and its calculation method is as follows:

[0048]

[0049] Here, x and y are input parameters in the CORDIC algorithm, where x represents one component of the input angle or coordinate, y represents another component of the input angle or coordinate, z represents an intermediate variable used in the CORDIC algorithm for auxiliary calculations, m represents the coordinate system, and δ... i Indicates the direction of rotation, θ i The value represents the rotation angle, and N represents the number of iterations.

[0050] Rotation angle θ i The definition is as follows:

[0051]

[0052] When m=1, it represents a circular system; when m=0, it represents a linear system; when m=-1, it represents a hyperbolic system. By setting different values ​​of m, the CORDIC algorithm can be applied to handle different types of mathematical operations and geometric transformations.

[0053] Rotation direction δ i The definition is as follows:

[0054]

[0055] The parameters x, y, and z will be explained further below.

[0056] x typically represents an input angle or a component of a coordinate system. In the CORDIC algorithm, x is one of the initial input parameters. For example, to calculate a sine function, x could represent the angle from which the sine value is to be calculated.

[0057] y is another input parameter in the CORDIC algorithm, corresponding to x. It typically also represents another component of the input angle or coordinates. For the calculation of a sine function, y might represent the cosine of the angle.

[0058] z is the result or intermediate variable of the CORDIC algorithm. It gradually approximates the desired value during the algorithm's iterative process. When calculating the sine function, z continuously approaches zero.

[0059] The CORDIC algorithm iteratively adjusts the values ​​of x and y through a series of steps, while simultaneously calculating an intermediate variable z that approximates the desired result. Each iteration involves rotation and translation operations, causing the values ​​of x and y to gradually approach the required angle or value, while z serves as an auxiliary variable recording the approximation result during the iteration process. This algorithm can be implemented using hardware circuitry or programmed in software to perform mathematical operations such as trigonometric functions, inverse trigonometric functions, and various rotational transformations.

[0060] The following section provides a detailed explanation of the different values ​​of m.

[0061] m = +1: The corresponding system is called a circular system. In this system, the CORDIC algorithm is used to calculate trigonometric functions, such as sine and cosine, or other rotational operations. It is suitable for handling circular-related problems.

[0062] m = 0: The corresponding system is called a linear system. In such a system, the CORDIC algorithm can be used to perform linear transformations or handle linearly dependent problems. In this mode, the CORDIC algorithm does not involve the calculation of trigonometric functions, but performs other types of operations.

[0063] m = -1: The corresponding system is called a hyperbolic system. In such systems, the CORDIC algorithm is typically used to compute hyperbolic functions, such as hyperbolic sine and hyperbolic cosine, or other operations related to hyperbolas.

[0064] By setting different values ​​for m, the CORDIC algorithm can be applied to handle different types of mathematical operations and geometric transformations, making it a very flexible and efficient algorithm.

[0065] S103, perform redundancy and fault tolerance processing based on error correction coding based on the original SAR angle information to obtain a second output result. The second output result is the SAR angle information after the fault tolerance backup override operation.

[0066] This step can be achieved in the following way:

[0067] S103.1, Linearly encode the input data and the input data processed in the first N-1 iterations to obtain the encoded data;

[0068] S103.2, perform the iterative processing on the encoded data once to obtain a second output result for error correction processing.

[0069] S104, perform error detection and location processing based on the first output result and the second output result. If there is no error, return the first output result as the final result to the user. If there is an error, proceed to step 5.

[0070] In some embodiments, Hamming SEC encoding is used to implement error detection and location.

[0071] S105, perform error correction processing on the first output result based on the second output result, and return the first output result after error correction to the user as the final result.

[0072] According to another aspect of the invention, such as Figure 3 As shown, a CORDIC fault-tolerant device for SAR imaging angle calculation is provided. The device includes an acquisition module, an iteration module, an error correction precoding module, a fault-tolerant module, and an error detection and localization error correction module. Each module is described in detail below.

[0073] The acquisition module is used to acquire raw SAR angle information. The raw SAR angle information includes at least the phase factor.

[0074] An iteration module, connected to the acquisition module, is used to perform iterative processing using the original SAR angle information to obtain a first output result, wherein the first output result is the SAR angle information after transcendence operation.

[0075] The iteration module is also used for:

[0076] The original SAR angle information is processed N times through iteration. This iteration is based on the CORDIC algorithm, and its calculation method is as follows:

[0077]

[0078] Here, x and y are input parameters in the CORDIC algorithm, where x represents one component of the input angle or coordinate, y represents another component of the input angle or coordinate, z represents the result in the CORDIC algorithm, m represents the coordinate system, and δ... i Indicates the direction of rotation, θ i The value represents the rotation angle, and N represents the number of iterations.

[0079] Rotation angle θ i The definition is as follows:

[0080]

[0081] When m=1, it represents a circular system; when m=0, it represents a linear system; when m=-1, it represents a hyperbolic system. By setting different values ​​of m, the CORDIC algorithm can be applied to handle different types of mathematical operations and geometric transformations.

[0082] Rotation direction δ i The definition is as follows:

[0083]

[0084] The parameters x, y, and z will be explained further below.

[0085] x typically represents an input angle or a component of a coordinate system. In the CORDIC algorithm, x is one of the initial input parameters. For example, to calculate a sine function, x could represent the angle from which the sine value is to be calculated.

[0086] y is another input parameter in the CORDIC algorithm, corresponding to x. It typically also represents another component of the input angle or coordinates. For the calculation of a sine function, y might represent the cosine of the angle.

[0087] z is the result or intermediate variable of the CORDIC algorithm. It gradually approximates the desired value during the algorithm's iterative process. When calculating the sine function, z continuously approaches zero.

[0088] The CORDIC algorithm iteratively adjusts the values ​​of x and y through a series of steps, while simultaneously calculating an intermediate variable z that approximates the desired result. Each iteration involves rotation and translation operations, causing the values ​​of x and y to gradually approach the required angle or value, while z serves as an auxiliary variable recording the approximation result during the iteration process. This algorithm can be implemented using hardware circuitry or programmed in software to perform mathematical operations such as trigonometric functions, inverse trigonometric functions, and various rotational transformations.

[0089] The following section provides a detailed explanation of the different values ​​of m.

[0090] m = +1: The corresponding system is called a circular system. In this system, the CORDIC algorithm is used to calculate trigonometric functions, such as sine and cosine, or other rotational operations. It is suitable for handling circular-related problems.

[0091] m = 0: The corresponding system is called a linear system. In such a system, the CORDIC algorithm can be used to perform linear transformations or handle linearly dependent problems. In this mode, the CORDIC algorithm does not involve the calculation of trigonometric functions, but performs other types of operations.

[0092] m = -1: The corresponding system is called a hyperbolic system. In such systems, the CORDIC algorithm is typically used to compute hyperbolic functions, such as hyperbolic sine and hyperbolic cosine, or other operations related to hyperbolas.

[0093] By setting different values ​​for m, the CORDIC algorithm can be applied to handle different types of mathematical operations and geometric transformations, making it a very flexible and efficient algorithm.

[0094] The error correction precoding module is connected to the iteration module and performs redundancy and fault tolerance processing based on the original SAR angle information, so that the first output result can be corrected based on the second output result in the subsequent process.

[0095] The error correction precoding module also includes:

[0096] The encoding unit performs linear encoding on the input data and the input data processed in the first N-1 iterations to obtain the encoded data.

[0097] Fault-tolerant calculation unit: performs the iterative processing on the encoded data once to obtain a second output result for error correction processing.

[0098] The fault-tolerant module is connected to the error-correcting precoding module and obtains a second output result through iterative calculation. The second output result is the SAR angle information after the fault-tolerant backup override operation.

[0099] An error detection and localization correction module is connected to the fault tolerance module. It performs error detection and localization processing based on the first output result and the second output result. If there is no error, it returns the first output result as the final result to the user. If there is an error, it performs error correction and returns the corrected first output result as the final result to the user.

[0100] In some embodiments, Hamming SEC encoding is used to implement error detection and location.

[0101] Figure 4 The diagram shown is a complete architecture diagram of the particle size flow-through fault-tolerant CORDIC device of the present invention.

[0102] The upper part mainly consists of four iterative modules (Iterative Module 1, Iterative Module 2, Iterative Module 3, and Iterative Module 4), used for angle calculation in SAR imaging. Each iterative module is as follows: Figure 5As shown. Specifically, the iterative module receives an n-bit input vector and a rotation angle θ, and then outputs an n-bit rotated vector through continuous vector rotation calculations. In the vector rotation calculation, each rotation calculation unit receives the vector output from the previous level, the remainder of the previous level's output, and the current rotation angle, and then calculates the vector output from the current level, the remainder of the current level's output, and the rotation angle of the next level.

[0103] Figure 4 The lower part is a fault-tolerant module, which is connected to the iteration module and is used to detect and correct calculation errors in real time.

[0104] The fault-tolerant module mainly includes an error correction coding unit, a fault-tolerant calculation unit, and an error detection unit. Among them:

[0105] The error correction coding unit receives input data and performs error correction coding on it. Specific coding methods and error location are as follows: Figure 6 As shown.

[0106] When using Hamming SEC coding to protect a granular pipelined CORDIC processor with granularity M=4, three additional redundant modules are used. In practice, the number of backups depends on the formula:

[0107] 2 r ≥k+r+1, where k and r represent the number of original modules and redundant modules, respectively. As parallelism increases, the additional overhead of protection decreases in a logarithmic manner.

[0108] Assuming the check bit is C2C1C0, the value of C0 will be determined by whether Z4' is equal to the sum of Z1+Z2+Z3. For example... Figure 4 As shown, Z1 to Z4 represent the z-component output values ​​of iteration modules one through four. Z5', Z6', and Z7' represent the outputs of iteration modules five, six, and seven. If Z5' = Z1 + Z2 + Z3, the value of C0 is 1; otherwise, the value of C0 is 0. The same method is used to obtain the values ​​of C1 and C2, that is: if Z6' = Z1 + Z2 + Z4, the value of C1 is 1; otherwise, the value of C1 is 0. If Z7' = Z1 + Z3 + Z4, the value of C2 is 1; otherwise, the value of C2 is 0.

[0109] When an error occurs, the faulty module can be corrected by utilizing the output of redundant modules. For example, if Z1 has an error, (Z1) c =Z5'-Z2-Z3 can be corrected using a formula.

[0110] The different Hamming SEC coding error localization modes are summarized as follows: Figure 6As shown, it can detect and correct individual error conditions in four original modules, as well as individual error conditions in three redundant modules.

[0111] The fault-tolerant computation unit, connected to the error-correcting coding unit, receives the data processed by the error-correcting coding unit and performs corresponding iterative calculations. The fault-tolerant computation unit can be implemented using comparators, state machines, or other techniques; no specific limitations are specified here.

[0112] An error detection unit, connected to the fault-tolerant calculation unit, is used to detect calculation errors in real time and feed them back to the data processing module for fault-tolerant processing.

[0113] By applying error-correcting coding techniques and fault-tolerant computing, stronger protection can be provided with lower resource overhead, thereby improving system reliability.

[0114] The data processing module, connected to the fault-tolerant module, is used for subsequent processing of the calculation results.

[0115] The data processing module also includes a control logic unit and a data input / output unit. Among them:

[0116] Control logic unit, used for:

[0117] a. Perform data reading, writing, and caching, and control the data flow based on the calculation results output by the iterative module. In this step, the calculation results are stored and retrieved for subsequent processing and analysis.

[0118] b. After receiving the error information from the error correction coding unit in real time, the entire calculation process is refreshed to recover from the error and ensure the continuity and correctness of the calculation.

[0119] The input / output unit is connected to the control logic unit and is used for data reading, writing, and caching.

[0120] The device of the present invention can be applied to VLSI circuit systems such as FPGAs to achieve high-performance SAR image processing.

[0121] In summary, a CORDIC fault-tolerant device for SAR imaging angle calculation mainly includes the following characteristics:

[0122] 1) Four original iterative modules for SAR imaging angle calculation;

[0123] 2) Error correction module, used to provide fault tolerance protection for the original iterative module, which includes:

[0124] a) Encoding unit, used to encode data in 4 / 3 ECC format.

[0125] b) Fault-tolerant calculation unit, used to perform corresponding iterative calculations on the encoded data.

[0126] c) Used to detect calculation errors in real time and feed them back to the fault tolerance module for fault tolerance processing.

[0127] 3) Fault-tolerant module, used to process the calculation results. It mainly includes control logic unit and data input / output unit.

[0128] Compared with the prior art, the beneficial effects of the present invention are:

[0129] 1. By introducing a fault-tolerant module, this invention can effectively improve the fault-tolerant performance of this type of CORDIC processor.

[0130] 2. Compared with traditional fault-tolerant technologies such as triple redundancy, the fault-tolerant CORDIC processor of this invention can significantly reduce resource consumption, thus playing an important role in fields such as SAR imaging.

[0131] 3. It can detect and correct errors in real time during SAR imaging, enabling highly reliable SAR image processing.

[0132] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in the present invention, or make equivalent substitutions for some of the technical features. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A CORDIC fault-tolerant method for SAR imaging angle calculation, characterized in that, The method includes: S101: Obtain the raw SAR angle information; S102: Iterative processing is performed using the original SAR angle information to obtain a first output result, wherein the first output result is the SAR angle information after transcendence operation; the transcendence operation includes repeating the iterative processing at least four times. S103: Based on the original SAR angle information, perform redundancy and fault tolerance processing based on error correction coding to obtain a second output result. The second output result is the SAR angle information after the fault tolerance backup override operation. S104: Perform error detection and location processing based on the first output result and the second output result. If there is no error, return the first output result as the final result to the user. If there is an error, execute S105. S105: Based on the second output result, perform error correction processing on the first output result, and return the first output result after error correction as the final result to the user.

2. The method as described in claim 1, characterized in that, The original SAR angle information includes at least the phase factor.

3. The method as described in claim 1, characterized in that, The iterative processing using the original SAR angle information to obtain the first output result includes: The original SAR angle information is processed N times through iteration. This iteration is based on the CORDIC algorithm, and its calculation method is as follows: Here, x and y are input parameters in the CORDIC algorithm, where x represents one component of the input angle or coordinate, y represents another component of the input angle or coordinate, z represents an intermediate variable used in the CORDIC algorithm for auxiliary calculations, and m represents the coordinate system. Indicates the direction of rotation. The value represents the rotation angle, and N represents the number of iterations. The rotation angle The definition is as follows: when m =1 represents a circular system. m =0 represents a linear system. m =-1 represents a hyperbolic system; by setting... m With different values, the CORDIC algorithm is suitable for handling different types of mathematical operations and geometric transformations; The direction of rotation The definition is as follows: 。 4. The method as described in claim 3, characterized in that, The step of performing redundancy-tolerant processing based on error correction coding on the original SAR angle information to obtain the second output result includes: S103.1, Linearly encode the input data and the input data processed in the first N-1 iterations to obtain the encoded data; S103.2: Perform the iterative processing on the encoded data once to obtain a second output result for error correction processing.

5. The method as described in claim 1, characterized in that, The error detection and localization process based on the first output result and the second output result includes: Hamming SEC encoding is used to implement error detection and location.

6. A CORDIC fault-tolerant device for SAR imaging angle calculation, characterized in that, The device includes: The acquisition module is used to acquire raw SAR angle information; An iterative module, connected to the acquisition module, is used to perform iterative processing using the original SAR angle information to obtain a first output result. The first output result is the SAR angle information after transcendence operation, and the transcendence operation includes iterative processing repeated at least four times. The error correction precoding module is connected to the iteration module and performs redundancy and fault tolerance processing based on the original SAR angle information, so that the first output result can be corrected based on the second output result in the subsequent process. The fault-tolerant module is connected to the error correction precoding module and obtains a second output result through iterative calculation. The second output result is the SAR angle information after the fault-tolerant backup override operation. An error detection and localization correction module is connected to the fault tolerance module. It performs error detection and localization processing based on the first output result and the second output result. If there is no error, it returns the first output result as the final result to the user. If there is an error, it performs error correction and returns the corrected first output result as the final result to the user.

7. The apparatus as claimed in claim 6, characterized in that, The original SAR angle information includes at least the phase factor.

8. The apparatus as claimed in claim 6, characterized in that, The iteration module is also used for: The original SAR angle information is processed N times through iteration. This iteration is based on the CORDIC algorithm, and its calculation method is as follows: Here, x and y are input parameters in the CORDIC algorithm, where x represents one component of the input angle or coordinate, y represents another component of the input angle or coordinate, z represents an intermediate variable used in the CORDIC algorithm for auxiliary calculations, and m represents the coordinate system. Indicates the direction of rotation. The value represents the rotation angle, and N represents the number of iterations. The rotation angle The definition is as follows: when m =1 represents a circular system. m =0 represents a linear system. m =-1 represents a hyperbolic system; by setting... m With different values, the CORDIC algorithm can be applied to handle different types of mathematical operations and geometric transformations; The direction of rotation The definition is as follows: 。 9. The apparatus as claimed in claim 8, characterized in that, The error correction precoding module also includes: The encoding unit performs linear encoding on the input data and the input data processed in the first N-1 iterations to obtain the encoded data. Fault-tolerant calculation unit: performs the iterative processing on the encoded data once to obtain a second output result for error correction processing.

10. The apparatus as claimed in claim 6, characterized in that, The error detection and localization module is also used to: implement error detection and localization using Hamming SEC encoding.

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