A Radar Angle Error Correction Method Based on Self-calibration Amplitude Normalization

Abstract

The present invention discloses a radar angle error correction method based on self-calibration amplitude normalization. The method includes the following steps: S1. Use sum-difference channel data to perform amplitude comparison and phase comparison processing to obtain radar angle error; S2. The radar angle error is normalized to the self-calibration amplitude of the current frame to obtain the normalized radar angle error; S3, the normalized radar angle error is aligned with the calibration angle curve to obtain the final angle measurement result. Its advantages are: the method utilizes the correspondence between the radar system angle detection curve and the self-calibration amplitude of the sum-difference channel, normalizes the angle detection curve and the radar angle error by using the self-calibration amplitude, and conducts the measurement of the radar target angle. The correction further improves the radar angle measurement accuracy, and this method is widely used in applications that require high radar angle measurement accuracy.

Description

technical field [0001] The invention relates to the field of radar system monopulse angle measurement, in particular to a radar angle error correction method based on self-calibration amplitude normalization. Background technique [0002] The main technical methods of the existing radar monopulse angle measurement technology are: using the antenna and difference channel data, through the amplitude ratio calculation to obtain the radar angle error; then through the angle detection curve fitting to obtain the real direction of arrival and front. The angle between the normal directions. [0003] For tracking or guidance radar, the radar's servo control system or wave control system uses the radar angle error to control the radar beam tracking convergence speed to complete the angle tracking of the target. The larger the radar angle error, the faster the tracking speed. In this case the radar angle error only provides information on a movement trend. [0004] For the search ra...

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Problems solved by technology

[0006] Among them, the papers include: (1) "The Influence of Inconsistent Amplitude and Phase of Monopulse Radar on the Angle Measurement Characteristics" of "Sichuan Military Engineering Journal" in August 2015, Volume 36, Issue 8. Angle principle, pointing out that the influence of the amplitude inconsistency of the sum and difference channel on the angle measurement is greater than the influence of the phase inconsistency of the sum and difference channel on the angle measurement, but it does not give a method to improve the influence of the inconsistency of the sum and difference channel amplitude on the angle measurement

[0007] (2) "Adaptive Monopulse Angle Measurement Method Based on Angle Discrimination Curve Fitting" in "System Engineering and Electronic Technology", Volume 35, Issue 7, July 2013, this paper proposes a method based on angle discrimination curve fitting A self-adaptive single-pulse angle measurement method, although this method involves angle detection curve fitting, does not analyze the influence of the channel self-calibration amplitude on the angle detection curve

[0008] (3) Modern Defense Technology, June 2017, Volume 45, Issue 3, "A New Method for High-Resolution Angle Measurement of Monopulse Radar Four-channel Combination", this paper proposes a new monopulse radar system structure, The received signal of the radar diagonal difference channel is cleverly extracted and utilized to improve the angle measurement resolution of the traditional radar system, but this method involves the flexible application of the four antenna channels, and does not involve the self-calibration amplitude to the angle measurement error Impact

[0009] (4) "An Improved Phased Array Radar and Differential Beam Angle Measurement Method" in "Radar and Countermeasures", Volume 38, Issue 1, March 2018. The improved method proposed in this paper refers to the geodetic coordinate system The beam steering angle is converted to the sinusoidal space, and the characteristic that the antenna pattern does not change with the beam pointing in the sinusoidal space makes it unnecessary to store multiple antenna patterns with different beam pointing angles to achieve the purpose of saving hardware resources, but it does not give A specific analysis of the influence of the self-calibration range on the angle measurement accuracy

[0010] (5) "Science and Technology Consulting Report" 2007, No. 15 "Research on Single Pulse Angle Measurement and Correction Method of Broadband Phased Array System", this paper proposed a variable substitution method to eliminate the frequency and scanning angle-sensitive function , but did not mention the influence of the self-calibration amplitude on the angle-sensitive function, and did not give the corresponding improvement method

[0012] (7) "Communication Countermeasures" in September 2016, Volume 35, Issue 3, "A Method for Automatic Phase Calibration and Single-Pulse Direction Finding on Satellite", this paper proposes a non-linear filtering method to calculate the radiation source position and Simultaneously estimate the phase difference of the sum and difference channel to realize the rapid and accurate positioning of the radiation source. This method involves the estimation of the phase difference of the sum and difference channel, but does not mention the amplitude difference between the sum and difference channel (that is, the self-calibration amplitude) Influence on Angle Measurement Accuracy

[0014] (1) "A single-pulse high-precision angle measurement system and its method", patent number: CN 103792532 A, this patent proposes a method that uses the sum and difference amplitude phase information and OBA (Off Boresight Angle, off the antenna beam aiming axis angle) value function to calculate the target azimuth, and did not calculate the angle measurement accuracy of this method, nor did it analyze the related influence brought about by the difference in the self-calibration amplitude of the sum difference channel

[0015] (2) "A Realization Method of High-precision Angle Measurement Technology Based on Amplitude Monopulse", Patent No.: CN 106990400A, this patent is a patented technology for air traffic control radar response angle measurement, which is different from traditional monopulse angle measurement Big difference, so there is no substantial relationship with the technical method of this patent

However, due to the wide radar beam width, beam sweep positioning alone cannot meet the positioning accuracy requirements, and the conventional sum-difference angle measurement method has a certain error in the angle-discrimination curve fitting, which can only be used for the trend of the target position and is suitable for the target position. Beam tracking and proportional guidance systems are not suitable for some application scenarios that require high positioning accuracy

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