Method for generating broadband dechirp echoes based on sweep frequency data

Abstract

The invention discloses a method for generating broadband dechirp echoes based on sweep frequency data, and belongs to the technical field of radar signal processing. The method comprises the steps: enabling a pulse radar to send a linear frequency modulation pulse signal to a detection target comprising Q scattering centers; enabling each scattering center in the detection target to feed back signals to the radar to obtain broadband echo signals of Q scattering centers; setting a reference signal, and performing dechirping processing on the broadband echo signal of each scattering center to obtain a frequency response containing a target RCS characteristic; carrying out fast Fourier inverse transformation on the frequency response containing the RCS characteristics of the target, carryingout inverse transformation on each scattering center to obtain a complex amplitude, and forming a one-dimensional range profile of the detection target by Q complex amplitudes; multiplying the one-dimensional range profile of the detection target by the dechirping echo signal of each scattering center, and performing accumulating and summing to finally obtain the broadband dechirping echo of thewhole detection target. According to the method, the operand is greatly reduced, and meanwhile, the precision and the accuracy which are the same as those of convolution operation are ensured.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, in particular to a method for generating broadband deslanting echoes based on frequency sweep data, which is used to reduce the calculation amount for generating radar deslanting echoes. Background technique [0002] Broadband signals are widely used in radar, navigation and satellite communications and other fields. The broadband signal is a signal whose fractional bandwidth is between 10% and 25%, and has the advantages of high distance resolution and high moving target detection characteristics. Due to the wide bandwidth, the system is required to have a high sampling rate. In this way, on the one hand, it brings great difficulties to data acquisition; on the other hand, even if the signal acquisition problem of the analog-to-digital converter (ADC) is solved, the excessively high sampling rate will lead to a sharp increase in the amount of subsequent processing data. , the p...

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Problems solved by technology

In this way, on the one hand, it brings great difficulties to data acquisition; on the other hand, even if the signal acquisition problem of the analog-to-digital converter (ADC) is solved, the excessively high sampling rate will lead to a sharp increase in the amount of subsequent processing data. , the processing speed, storage capacity and input and output speed of the signal processing system are all required to increase accordingly.

[0003] Broadband signal processing methods include: matched filtering and sub-band segmentation technology, etc. The matched filtering method is limited by the development level of processing devices. When the bandwidth of the processing signal is wide, it is difficult to use this method; The received broadband signal is divided into multiple subbands, and each subband is processed separately, but the phase coherence between subbands is difficult to guarantee, which limits the wide application of this method. In this case, the deskewing pulse compression method is widely used

[0004] In order to make the wideband de-skewing echo of the target accurately reflect the wideband RCS characteristics of the target in the simulation, there are two methods: one is to modulate the wideband RCS characteristics of the target in the chirp received echo, but due to the sampling of the chirp received signal The rate is relatively high, and the number of sampling points is relatively large, which will lead to a very large amount of calculation; the other type is to modulate the broadband RCS characteristics of the target in the broadband deslant echo, because the sampling rate of the broadband deslant echo is relatively low, and the number of sampling points is relatively large. less, and the amount of calculation is very small

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