Jet aircraft positioning method based on double-cross function

Abstract

The invention relates to a jet aircraft positioning method based on a double-crossover function. According to the method, at least seven geophones are needed, firstly, a double-cross function is used for calculating the relation between time scale factors and time delay between a first channel signal and other channel signals, time delay estimation values of the first channel signal and other channel signals are obtained, then time delay correction is conducted on all channel signals, and time delay estimation values of all channel signals are obtained. Fourier transform is carried out on all channels of signals to obtain frequency spectrums of the signals, relative Doppler frequency shifts of the frequency spectrum of the first channel of signals and the frequency spectrums of other channels of signals are calculated by using a double-cross function, and an equation containing target flight speed and position information is obtained by subtracting one from the total number of detectors; and finally, solving the equation set by using a genetic algorithm to obtain the position and speed information of the jet aircraft. The method solves the broadband Doppler frequency shift interference problem of the jet aircraft, can obtain the target position and speed information at the same time, and is suitable for both broadband signals and narrowband signals.

Description

Technical field: [0001] The invention relates to a jet aircraft positioning method based on a double cross function, which is suitable for positioning and tracking of jet aircraft by seismic arrays, and is also applicable to acoustic arrays with relatively large array spacing, involving signal acquisition and geophone arrays the field of signal processing. Background technique: [0002] Jet aircraft, especially low-altitude combat jet aircraft, are easy to be blocked in some special and complex terrains such as mountains, hills, virgin forests, etc., due to their flight altitudes generally within the range of 100 meters. Due to the small radar cross-section, it is generally difficult to find such targets, and the clutter interference reflected by the near-surface layer will also reduce the detection capability of the radar. Therefore, the existing low-altitude target positioning is generally completed through acoustic arrays. However, in military environments, acoustic sens...

AI Technical Summary

Problems solved by technology

[0003] Due to the high frequency of the main frequency band of the acoustic signal, the high sampling rate of the signal, the small distance between the detectors, and the small influence of the relative Doppler frequency shift, the existing sound positioning methods generally ignore the relative Doppler frequency shift of different channel signals. , but for the geophone array, the frequency of the main frequency band of the seismic signal is low, the wavelength is long, and the distance between the geophone arrays is relatively large, so the relative Doppler frequency shift of different channel signals has a great influence and cannot be ignored

Acoustic array positioning technology can basically be divided into three categories: one is the positioning estimation based on the sound arrival time difference, and the target position is calculated through the geometric relationship of the array, which has a small amount of calculation and is better for stationary targets. Due to the Doppler frequency shift problem, the positioning effect of moving targets is poor, such as CN104991573A; the second is the beamforming technology based on the maximum output power, the direction of arrival estimation is more accurate, the disadvantage is that this method relies on more detectors, and the calculation The amount is too large, and the influence of Doppler frequency shift is not considered in the delay beamforming of moving targets, such as CN112666520A; the third is based on high-resolution spectrum technology, which is suitable for narrowband signals and locates broadband signals generated by jet aircraft Effect is relatively poor, as CN113126028A; The positioning technology of seismic array has only the narrow-band Doppler frequency shift fitting method that Eibl proposes, also can't solve the broadband signal location that jet plane produces; The localization problem of broadband target sources such as jet aircraft

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