Radar angle measurement method

Abstract

The invention discloses a radar angle measurement method. After a radar detects a target, the radar emits a chirp signal, the chirp signal is reflected by the target, two reception antennas receive echo signals respectively, and the echo signals are obtained. The emission signal is employed as a reference signal, the two echo signals are subjected to dechirp processing, namely, the reference signal and the echo signals are subjected to slip frequency processing, two signals after dechirp processing are obtained, the two signals after dechirp processing are subjected to conjugate cross-correlation operation, a conjugate cross-correlation function is obtained, a frequency value corresponding to a position of a highest spectrum peak is estimated, and according to the linear relation of the frequency value and wave path difference of the echo signals received by the two reception antennas respectively and a trigonometric function relation of the wave path difference and the spacing between the two reception antennas, the angle of the target is calculated and obtained. Through the method, the angle measurement errors can be reduced, the angle measurement precision is raised, and the multi valuedness problem of angle measurement results is avoided.

Description

technical field [0001] The invention relates to the technical field of radar, in particular to a method for measuring angles by radar. Background technique [0002] Angle measurement refers to the determination of the pitch angle and azimuth angle of the target, which is an important part of target orientation. [0003] The traditional phase comparison method uses the phase difference between the echo signals received by two antennas to measure the angle. figure 2 It is a simulation diagram of the working principle of the receiving antenna when the radar uses the traditional phase comparison method to measure the angle. The distance between the two receiving antennas is d, which leads to the time difference between the echo signal reaching the two receiving antennas. Therefore, the echo signals received by the two receiving antennas have a wave path difference ΔR, that is, the phase difference of the two echo signals is Δφ. Let θ be the angle to be measured, then we can ge...

AI Technical Summary

Problems solved by technology

There are two main disadvantages in the traditional phase comparison method for angle measurement: one is that when the angle of the target to be measured increases, the angle measurement error also increases. In order to ensure a certain angle measurement accuracy, the range of the angle of the target to be measured is limited; In the angle measurement range, when the ratio of the antenna spacing to the radar wavelength increases to a certain extent, the Δφ value may exceed 2π, at this time Δφ=2πN+ψ, where N is an integer, ψ<2π, and the actual reading of the phase comparison device is the value of ψ

Since the value of N is unknown, the real value of Δφ cannot be determined, and there will be a problem of multi-value

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