CN114415127A - Calibration method and device for polarization active scaler channel balance - Google Patents

Abstract

The invention provides a calibration method and a calibration device for polarization active scaler channel balance. The method comprises the following steps: performing matched filtering processing on the linear frequency modulation pulse signal recorded in each polarization channel experiment in the polarization active scaler to obtain a pulse compression signal; carrying out interpolation processing on the pulse compression signal, and extracting the amplitude and the phase at the peak value of the pulse compression signal to obtain an amplitude-phase characteristic value; comparing the amplitude-phase characteristic values corresponding to two adjacent pulse compression signals to obtain the pulse signal attenuation rate corresponding to each polarization channel; comparing the relation of the pulse signal attenuation rate between each polarization channel and the reference polarization channel by taking the pulse signal attenuation rate of a preset reference polarization channel as a reference to obtain an amplitude-phase balance value between the polarization channels in the polarization active scaler; and calibrating a polarization channel in the polarization active calibrator based on the amplitude-phase balance value. The method can improve the calibration accuracy of the channel balance of the polarization active scaler and reduce the cost.

Description

A method and device for calibrating the channel balance of a polarized active scaler

technical field

The invention relates to the technical field of amplitude and phase balance calibration, in particular to a method and device for calibration of the channel balance of a polarization active scaler. In addition, it also relates to a calibration device for a polarized active scaler, an electronic device and a non-transitory computer-readable storage medium.

Background technique

Active Radar Calibrator (ARC: Active Radar Calibrator) is an important device for polarization Synthetic Aperture Radar (SAR: Synthetic Aperture Radar) calibration, which can achieve very high radar cross-sectional area and calibrate SAR radiation with lower resolution. It is very necessary in and polarization calibration, and it is difficult to replace it with other equipment. When a polarimetric active calibrator (PARC: Polarimetric Active Radar Calibrator) is used for polarimetric synthetic aperture radar calibration, it is required that the polarimetric active calibrator can provide four polarization channels of hh, hv, vh and vv. Signal forwarding function, and the amplitude and phase of the four polarization channels are required to have high consistency. Therefore, the calibration of the amplitude and phase balance between the four channels of the polarization active calibrator for the calibration of the polarization synthetic aperture radar is studied, which is the amplitude and phase balance between the four channels of the polarization active calibrator. It has become a current research hotspot to provide reliable technical solutions for sex-standard schools.

In the prior art, there are various techniques for calibrating the radar cross-sectional area of the polarized active scaler, and this problem already has mature techniques. The radar cross-sectional area calibration of the pure co-polarized channel can adopt the calibration method of the existing polarization active calibrator. However, for the calibration of the amplitude and phase balance between multiple polarization channels, the method commonly used at present is to use instruments to directly measure, such as signal generators, spectrum analyzers and other signal generation and measurement instruments. The amplitude and phase characteristics of the channels are measured separately, and then the multiple polarization channels are compared with each other to obtain the amplitude and phase balance characteristics of the multiple polarization channels of the polarization active scaler. The specific measurement principle is: connect a signal source or a vector network analyzer at the back end of the receiving antenna of a certain channel to be measured or at the entrance of the electrical signal, fill in a signal of a certain characteristic and power, and then connect the signal at the front end of the transmitting antenna or the electrical signal outlet. Connect the spectrum analyzer or vector network analyzer at the place, record and measure the output signal, and obtain the amplitude and phase of the output signal of the channel. Keep the signal input by the signal source unchanged, record and measure the amplitude and phase of the output signals of the other channels to be tested, and compare the differences between the output amplitude and phase signals of multiple polarization channels to obtain multiple polarizations of the polarization active scaler. Amplitude and phase balance between channels. You can also use a vector network analyzer to inject signals into multiple input channels at the same time, connect the vector network analyzer to the output port to record and measure the output signals at the same time, and obtain multiple polarizations of the polarization active scaler after comparison and analysis. Amplitude and phase balance between channels.

However, this approach has various problems and drawbacks. First of all, this method cannot measure the whole link, the antenna part is not included in the measurement link, and the obtained amplitude-phase balance between the polarization channels does not include the link of the antenna part. If there is a big difference between the multiple polarized channel antennas, there will be a large error in the measured amplitude and phase balance. Secondly, it is greatly affected by the accuracy and stability of the instrument, and the effect is not very good. No matter whether multiple polarization channels are measured sequentially or at the same time, there will be certain differences between the signals input to multiple channels. Accuracy also has problems in stability, which will introduce errors, which will introduce new errors in the measurement or calibration of the amplitude and phase balance between the channels of the polarized active scaler, resulting in the problem of reduced accuracy. It is very difficult to realize a polarization active scaler with high polarization isolation with multiple polarization channels independent of each other. For this reason, the polarization active scaler is usually realized by rotating the polarization antenna by 45°. , but the polarization scattering characteristics of this polarization active scaler are definite, the polarization scattering matrix cannot be set flexibly, and the polarization isolation degree of this polarization active scaler is poor, so the application is limited. In addition, this calibration method cannot give the radar cross-sectional area values of multiple polarization channels of the polarized active scaler, and it is necessary to calibrate the radar cross-sectional area values by other means. Therefore, in order to develop a polarization active scaler with multiple polarization channels independent of each other, which can flexibly set the scattering characteristic matrix according to the needs, and has high isolation between channels, it is necessary to design a set of effective polarization channel amplitude and phase. Balance calibration scheme and related equipment, thus providing strong support for calibration between polarization channels of polarization active scalers.

SUMMARY OF THE INVENTION

Therefore, the present invention provides a method and device for calibrating the channel balance of a polarization active scaler, so as to solve the limitation of the calibration scheme of the channel balance of the polarization active scaler in the prior art. problems with high, poor accuracy and stability.

The present invention provides a method for calibrating the channel balance of a polarization active scaler, comprising:

Perform matched filtering processing on the chirp signal corresponding to each polarization channel in the polarization active scaler to obtain a pulse compressed signal; perform interpolation processing on the pulse compressed signal to extract the amplitude at the peak value of the pulse compressed signal and the phase to obtain the amplitude and phase characteristic values; compare the amplitude and phase characteristic values corresponding to the two adjacent pulse compression signals to obtain the pulse signal attenuation rate corresponding to each polarization channel; use the preset reference polarization channel pulse signal The attenuation rate is the benchmark, and the amplitude-phase balance value between the polarization channels in the polarization active scaler is obtained by comparing the relationship between the attenuation rate of the pulse signal between each polarization channel and the reference polarization channel. ; calibrating the polarization channel in the polarization active scaler based on the amplitude-phase balance value.

Further, the polarization channels include hh polarization channels, hv polarization channels, vh polarization channels and vv polarization channels;

The reference polarization channel is one of the hh polarization channel, the hv polarization channel, the vh polarization channel, and the vv polarization channel.

Further, the calibration of the polarization channel in the polarization active scaler based on the amplitude-phase balance degree value specifically includes:

calibrating the hh polarization channel in the polarization active scaler based on the amplitude-phase balance value of the hh polarization channel relative to the reference polarization channel;

calibrating the hv polarization channel in the polarization active scaler based on the amplitude and phase balance value of the hv polarization channel relative to the reference polarization channel;

calibrating the vh polarization channel in the polarization active scaler based on the amplitude-phase balance value of the vh polarization channel relative to the reference polarization channel;

The vv polarized channel in the polarized active scaler is calibrated based on an amplitude-phase balance value of the vv polarized channel relative to the reference polarized channel.

所述极化有源定标器对应的标准反射器的极化散射矩阵为

所述极化有源定标器和所述标准反射器两者的距离为R；所述有源定标器包含p接收q发射通道，记作pq通道；设第1次记录的线性调频信号为

第2次记录的线性调频信号为

以此类推，得到第i次记录的线性调频信号为

则所述脉冲信号衰减率对应的表达式为：Further, if the polarization scattering matrix of the polarization active scaler is

The polarization scattering matrix of the standard reflector corresponding to the polarization active scaler is:

The distance between the polarized active scaler and the standard reflector is R; the active scaler includes a p-receive q-transmit channel, denoted as pq channel; set the chirp signal recorded for the first time for

The chirp signal recorded for the second time is

By analogy, the chirp signal recorded for the i-th time is obtained as

Then the expression corresponding to the decay rate of the pulse signal is:

为pq通道第i次记录的线性调频脉冲信号；

为pq通道第i+1次记录的线性调频脉冲信号；所述pq通道为hh通道、hv通道、vh通道、vv通道中的任意一个；S_pq表示所述极化有源定标器的极化散射矩阵中S_hh、S_hv、S_vh、S_vv中的任意一个；

是作为基准的已知量，表示所述标准反射器的极化散射矩阵中

中的任意一个。In the formula, λ is the signal wavelength, which is a chirp signal; i is an integer greater than or equal to 1, indicating the recorded serial number; R is the distance between the polarized active scaler and the standard reflector; p and q are variables, representing h or v respectively;

is the chirp signal recorded for the i-th time of the pq channel;

is the chirp signal recorded at the i+1th time of the pq channel; the pq channel is any one of the hh channel, hv channel, vh channel, and vv channel; S _pq represents the pole of the polarized active scaler any one of _{Shh, Shv , Svh} , and _Svv in the scatter matrix;

is a known quantity as a reference, indicating that in the polarization scattering matrix of the standard reflector

any of the .

Further, performing matched filtering processing on the chirp signal corresponding to each polarized channel in the polarized active scaler to obtain a pulse compressed signal; performing interpolation processing on the pulse compressed signal to extract the pulse compressed signal. The amplitude and phase at the peak of the signal are obtained to obtain the amplitude and phase eigenvalues, including:

和

进行匹配滤波处理，得到脉冲压缩信号；对所述脉冲压缩信号进行插值处理，提取所述脉冲压缩信号峰值的幅相数据，得到幅相特征值

和

The chirp signal of the polarization channel in the polarization active scaler recorded twice adjacently

and

Perform matched filtering processing to obtain a pulse compressed signal; perform interpolation processing on the pulse compressed signal, extract the amplitude and phase data of the peak value of the pulse compressed signal, and obtain the amplitude and phase characteristic value

and

The amplitude and phase characteristic values corresponding to two adjacent pulse compression signals are compared to obtain the pulse signal attenuation rate corresponding to each polarization channel, which specifically includes:

By comparing the amplitude and phase eigenvalues corresponding to two adjacent pulse compressed signals, the attenuation rate of the pulse compressed signal corresponding to each polarization channel is obtained. The corresponding formula is:

In the formula, p and q are variables, which can represent h or v respectively; Y _pq represents any one of Y _hh , Y _hv , Y _vh , and Y _vv ; i is an integer greater than or equal to 1, representing the serial number of the record; ΔY _pq is the pulse compression signal attenuation rate of two adjacent pulse compression signals to be calculated. Since p and q are variables, representing h or v, respectively, ΔY _pq represents ΔY _hh , ΔY _hv , ΔY _vh , and ΔY _vv . Any one; where ΔY _hh is the attenuation rate of the pulse compressed signal of the hh channel, ΔY _hv is the attenuation rate of the pulse compressed signal of the hv channel, ΔY _vh is the attenuation rate of the pulse compressed signal of the vh channel, and ΔY _vv is the pulse compressed signal of the vv channel Attenuation rate; the pulse compression signal attenuation rate corresponds to the pulse signal attenuation rate.

The present invention also provides a calibration device for the channel balance of the polarized active scaler, comprising:

The pulse signal attenuation rate obtaining unit is used to perform matched filtering processing on the chirp signal corresponding to each polarization channel in the polarization active scaler to obtain a pulse compressed signal; perform interpolation processing on the pulse compressed signal to extract The amplitude and phase at the peak of the pulse compression signal to obtain the amplitude-phase characteristic value;

The pulse signal attenuation rate obtaining unit is used to compare the amplitude and phase characteristic values corresponding to two adjacent pulse compression signals to obtain the pulse signal attenuation rate corresponding to each polarization channel;

Amplitude and phase balance degree value obtaining unit, used for taking the preset reference polarization channel's pulse signal attenuation rate as the benchmark, and by comparing the relationship between the pulse signal attenuation rate between each polarization channel and the reference polarization channel, to obtain Amplitude-phase balance value between polarization channels in the polarization active scaler;

A polarization channel calibration unit, configured to calibrate the polarization channel in the polarization active scaler based on the amplitude-phase balance value.

The present invention also provides a calibration device for a polarized active scaler, which is characterized by comprising: a pointing adjusting device and a corner reflector; the pointing adjusting device is used to control the pointing of the corner reflector; The corner reflector is used to reflect back the chirp signal emitted by the polarized active scaler transmitting antenna; wherein, none of the four elements of the polarization scattering characteristic matrix corresponding to the corner reflector is zero.

Further, the corner reflector is a dihedral corner reflector using a preset polarization rotation angle.

Correspondingly, the present invention also provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and running on the processor, the processor implementing the program as described in any of the above when the processor executes the program. The steps of the calibration method for the channel balance of the polarized active scaler described above.

Correspondingly, the present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, realizes the polarization active scaler channel described in any of the above The steps of the balanced calibration method.

By adopting the method for calibrating the channel balance of the polarization active calibrator of the present invention, the precise calibration of the amplitude and phase balance between the polarization channels of the polarization active calibrator as a whole can be realized, without the need for complicated and The high-precision signal measuring instrument reduces the cost and improves the stability of the calibration of the amplitude and phase balance.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic flowchart of a method for calibrating the channel balance of a polarization active scaler according to an embodiment of the present invention;

2 is a schematic diagram of a method for calibrating the channel balance of a polarization active scaler according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a proportional series decreasing schematic diagram of a pulse signal obtained in a polarization channel calibration process in a polarization active scaler provided by an embodiment of the present invention;

4 is a schematic structural diagram of a device for calibrating the channel balance of a polarization active scaler according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a physical structure of an electronic device according to an embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The invention proposes a calibration system comprising a polarimetric active calibrator (PARC: Polarimetric Active RadarCalibrator) and a calibration device. Based on the calibration device, the radar cross-sectional area value of each channel of the polarimetric active calibrator can be adjusted. calibration and accurate calibration of the amplitude and phase balance between the four polarization channels. As shown in FIG. 2 , the calibration system is composed of a support bracket 203 , a high-precision pointing adjustment device 201 , a high-precision standard reflector 202 (such as a dihedral corner reflector), and the like. The calibration equipment is composed of a support bracket 203 , a high-precision pointing adjustment device 201 , a high-precision standard reflector 202 and the like.

The calibration method of the channel balance of the polarization active scaler adopted in the present invention is realized based on the calibration system shown in FIG. 2 . Specifically, it is first necessary to set the distance (R) between the standard reflector and the polarized active scaler to satisfy the far-field condition, and the polarized active scaler transmitting antenna 206 and receiving antenna 205 are both aligned with the standard reflector, After the transmitted signal is reflected by the standard reflector, it reaches the receiving antenna, and is sampled and recorded by the detection and recording system in the polarized active scaler; then, the received signal is passed through the polarized active scaler to be calibrated inside the polarized channel ( For example, hh polarized channel, hv polarized channel, vh polarized channel or vv polarized channel) after the delay and amplification of the forwarding path, it is transmitted by the transmitting antenna, reflected by the standard reflector, and then by the polarized active scaler Receive, record and forward, and thus cycle continuously to obtain the corresponding echo pulse signal sequence. As shown in FIG. 3 , in the specific implementation process, the echo pulse signal sequence obtained by the receiving antenna of the polarized active scaler is a group of linear frequency modulated pulse signals that are attenuated in a proportional sequence.

Based on the method for calibrating the channel balance of the polarization active scaler according to the present invention, the embodiments thereof will be described in detail below. As shown in FIG. 1 , which is a schematic flowchart of a method for calibrating the channel balance of a polarized active scaler provided by an embodiment of the present invention, the specific implementation process includes the following steps:

Step 101: Perform matched filtering processing on the chirp signal corresponding to each polarization channel in the polarization active scaler to obtain a pulse compressed signal; perform interpolation processing on the pulse compressed signal to extract the peak value of the pulse compressed signal Amplitude and phase at the eigenvalues of amplitude and phase are obtained.

In the embodiment of the present invention, since the recorded chirp signal is inconvenient for direct measurement, it is necessary to first perform matched filtering processing on the chirp signal corresponding to each polarization channel in the polarization active scaler to obtain pulse compression signal; perform interpolation processing on the pulse compressed signal, extract the amplitude and phase at the peak value of the pulse compressed signal, and obtain the amplitude and phase characteristic values corresponding to the chirp signal. Wherein, the polarization channels of the polarization active scaler include four polarization channels: hh polarization channel, hv polarization channel, vh polarization channel and vv polarization channel.

It should be noted that, in the embodiment of the present invention, before sampling and recording the echo pulse signal of each polarization channel, it is necessary to pre-determine the polarization scattering characteristic matrix of the corner reflector and the polarization active calibration to determine the relative position distance parameter between the polarization active calibrator and the calibration device, so as to deploy the polarization active calibrator and the calibration device in the target area The spatial relative position distance. Wherein, the relative position distance corresponding to the relative position distance parameter needs to make the echo pulse signal recorded in each sampling attenuate in a proportional sequence in the polarization active scaler. By selecting a suitable target area as the test site, and taking measures to eliminate or reduce the influence of interference signals, noise and clutter, and setting reasonable relative position distance parameters, the echo pulse signals obtained by each sampling can be made active in polarization The scaler is constantly attenuated to avoid self-excitation.

Step 102: Compare the amplitude and phase eigenvalues corresponding to two adjacent pulse compressed signals to obtain the pulse signal attenuation rate corresponding to each polarization channel.

Step 103: Based on the pulse signal attenuation rate of the preset reference polarization channel, by comparing the relationship between the pulse signal attenuation rate between each polarization channel and the reference polarization channel, the polarization active fixed signal is obtained. Amplitude and phase balance between polarization channels in the scaler.

In the implementation process, the radar cross-sectional area of the reference polarization channel can be calibrated first, and then the amplitude and phase balance between the four polarization channels of the polarization active calibrator can be calibrated to realize the radar of the four polarization channels. The calibration of the cross-sectional area value. The calibration of the radar cross-sectional area value of a single polarization channel will not be repeated in the present invention.

The main content of the present invention is the calibration of the amplitude and phase balance between the four polarization channels of the polarization active scaler, and the specific calibration principles include:

During calibration, the transmitting antenna of a polarization channel to be calibrated (such as hh polarization channel) of the polarization active scaler transmits the chirp signal generated by the external signal generator to the calibration equipment, and is received by the receiving antenna. The echo pulse signal reflected by the corner reflector (such as the dihedral corner reflector) of the calibration equipment, the reflected signal passes through the polarization active scaler to be calibrated after the polarization channel forwarding path is delayed and amplified, and then sent to the transmitting antenna. At the same time, the echo pulse signal passing through the polarization channel inside the polarization active scaler is sampled and recorded by the internal detection and recording system.

When calibrating the polarization channel to be calibrated of the polarization active calibrator, the amplitude and phase characteristic values of the preset reference polarization channel are used as the reference, and the relative value of each polarization channel to the reference polarization channel is compared. The relationship between the amplitude and phase eigenvalues is used to obtain the amplitude and phase balance value between the polarization channels in the polarization active scaler, so that the polarization channels of the polarization active scaler are calibrated one by one. Further, the amplitude and phase eigenvalues corresponding to two adjacent pulse compressed signals can be compared to obtain the pulse signal attenuation rate corresponding to each polarization channel, that is, the amplitude of the chirp signal recorded twice adjacent to the polarization channel. and phase decay rate. The amplitude and phase eigenvalues of the reference polarization channel are used as a reference, and the neutral pole of the polarization active scaler is obtained by comparing the relationship between the amplitude and phase eigenvalues of each polarization channel relative to the reference polarization channel. The amplitude and phase balance between the polarization channels can be specifically: based on the preset pulse signal attenuation rate of the reference polarization channel, by comparing the pulse signal attenuation between each polarization channel relative to the reference polarization channel According to the relationship between the ratios, the amplitude-phase balance value between the polarization channels in the polarization active scaler is obtained. For example, based on the attenuation rate of the pulse signal corresponding to the preset hh polarization channel, by comparing the four polarization channels (hh polarization channel, hv polarization channel, vh polarization channel) in the polarization active scaler channel and vv polarization channel) relative to the relationship between the pulse signal attenuation rate between the hh polarization channels, respectively obtain the amplitude and phase balance between the polarization channels in the polarization active scaler, based on the The amplitude and phase balance values are used to calibrate the four polarization channels in the polarization active scaler respectively.

For example, in the specific implementation process, the realization principle of obtaining the amplitude and phase balance value between the four polarization channels of the polarization active scaler is as follows:

标准反射器的极化散射矩阵为

极化有源定标器和标准反射器两者的距离为R。First, it is assumed that the polarization scattering matrix when the polarization active scaler is calibrated is

The polarization scattering matrix of the standard reflector is

The distance between the polarized active scaler and the standard reflector is R.

Among them, S _pq in the matrix represents the characteristic of receiving q-polarization scattering p-polarization, where p and q are both variables, which can be h or v. For example: p represents scattering h (horizontal polarization) or v (vertical polarization); q represents receiving h (horizontal polarization) or v (vertical polarization).

第2次记录的线性调频信号为

以此类推，第i次记录的线性调频信号为

等。确定线性调频脉冲信号衰减率模型，该线性调频脉冲信号衰减率模型用于计算脉冲信号衰减率，其对应的表达式为：In the case of ignoring noise, clutter and interfering signals. Taking the p-receive q-transmit channel (referred to as pq channel) of the active scaler shown in Figure 2 as an example, suppose the chirp signal recorded for the first time is

The chirp signal recorded for the second time is

By analogy, the chirp signal recorded for the i-th time is

Wait. Determine the decay rate model of the chirp signal, the decay rate model of the chirp signal is used to calculate the decay rate of the pulse signal, and its corresponding expression is:

为pq通道第i次记录的线性调频脉冲信号；

为pq通道第i+1次记录的线性调频脉冲信号；所述pq通道为hh通道、hv通道、vh通道、vv通道中的任意一个；S_pq表示所述极化有源定标器的极化散射矩阵中S_hh、S_hv、S_vh、S_vv中的任意一个；

是作为基准的已知量，表示所述标准反射器的极化散射矩阵中

中的任意一个。In the formula, λ is the signal wavelength, which is a chirp signal; i is an integer greater than or equal to 1, indicating the recorded serial number; R is the distance between the polarized active scaler and the standard reflector; p and q are variables, representing h or v respectively;

is the chirp signal recorded for the i-th time of the pq channel;

is the chirp signal recorded at the i+1th time of the pq channel; the pq channel is any one of the hh channel, hv channel, vh channel, and vv channel; S _pq represents the pole of the polarized active scaler any one of _{Shh, Shv , Svh} , and _Svv in the scatter matrix;

is a known quantity as a reference, indicating that in the polarization scattering matrix of the standard reflector

any of the .

After transforming the above formula (1), the following expression is obtained:

为pq通道第i次记录的线性调频脉冲信号；

为pq通道第i+1次记录的线性调频脉冲信号；所述pq通道为hh通道、hv通道、vh通道、vv通道中的任意一个；S_pq表示所述极化有源定标器的极化散射矩阵中S_hh、S_hv、S_vh、S_vv中的任意一个；

是作为基准的已知量，表示所述标准反射器的极化散射矩阵中

中的任意一个。In the formula, λ is the signal wavelength, which is a chirp signal; i is an integer greater than or equal to 1, indicating the recorded serial number; R is the distance between the polarized active scaler and the standard reflector; p and q are variables, representing h or v respectively;

is the chirp signal recorded for the i-th time of the pq channel;

is the chirp signal recorded at the i+1th time of the pq channel; the pq channel is any one of the hh channel, hv channel, vh channel, and vv channel; S _pq represents the pole of the polarized active scaler any one of _{Shh, Shv , Svh} , and _Svv in the scatter matrix;

is a known quantity as a reference, indicating that in the polarization scattering matrix of the standard reflector

any of the .

In the specific implementation process, in order to obtain the amplitude and phase balance between the polarization channels of the polarization active scaler, the amplitude and phase eigenvalues of the chirp signal of the preset reference polarization channel (such as the hh polarization channel) are used. As the reference, in order to obtain the amplitude and phase balance of the four polarization channels of the polarization active scaler with respect to the hh polarization channel, the following formula can be used:

为pq通道第i次记录的线性调频脉冲信号；

为pq通道第i+1次记录的线性调频脉冲信号；所述pq通道为hh极化通道、hv极化通道、vh极化通道、vv极化通道中的任意一个；S_pq表示所述极化有源定标器的极化散射矩阵中S_hh、S_hv、S_vh、S_vv中的任意一个；

是作为基准的已知量，表示所述标准反射器的极化散射矩阵中

中的任意一个。In the formula, λ is the signal wavelength, which is a chirp signal; i is an integer greater than or equal to 1, indicating the recorded serial number; R is the distance between the polarized active scaler and the standard reflector; p and q are variables, representing h or v respectively;

is the chirp signal recorded for the i-th time of the pq channel;

is the chirp signal recorded at the i+1th time of the pq channel; the pq channel is any one of the hh polarized channel, hv polarized channel, vh polarized channel, and vv polarized channel; S _pq represents the polar any one of _{Shh, Shv , Svh} , and _Svv in the polarization scattering matrix of the active scaler;

is a known quantity as a reference, indicating that in the polarization scattering matrix of the standard reflector

any of the .

According to formula (3), _{Shh /S hh =} 1, then the amplitude and phase balance of the hh polarized channel relative to the reference polarized channel (ie, the hh polarized channel) is obtained as 1. Correspondingly, the amplitude and phase balance of the hv polarized channel relative to the reference polarized channel (that is, the hh polarized channel) can be obtained as Shh/S _hv ; the _vh polarized channel relative to the reference polarized channel (that is, the hh polarized channel). The amplitude and phase balance value of the channel) is _{Shh /S vh ;} the amplitude and phase balance value of the vv polarized channel relative to the reference polarized channel (ie the hh polarized channel) is _Shh /S _vv .

和

进行匹配滤波处理，得到脉冲压缩信号，然后再进行插值处理，提取脉冲压缩信号峰值的幅相，得到幅相特征值

和

即将

和

转换为相应的幅相特征值

和

其中，

和

可用于表示所述脉冲压缩信号峰值处的幅相特征值。通过将相邻两个脉冲压缩信号对应的幅相特征值进行比较，可得到每个极化通道分别对应的脉冲压缩信号衰减率(即等同于上述脉冲信号衰减率)，对应的公式为：Further, in the specific implementation process, in order to facilitate direct measurement, the linear frequency modulation pulse signal of the polarization channel in the polarization active scaler recorded twice adjacently may be firstly recorded.

and

Perform matched filtering processing to obtain the pulse compressed signal, and then perform interpolation processing to extract the amplitude and phase of the peak value of the pulse compressed signal, and obtain the amplitude and phase eigenvalues

and

coming soon

and

Convert to the corresponding amplitude and phase eigenvalues

and

in,

and

It can be used to represent the amplitude and phase characteristic values at the peak of the pulse compressed signal. By comparing the amplitude and phase eigenvalues corresponding to two adjacent pulse compression signals, the corresponding pulse compression signal attenuation rate of each polarization channel can be obtained (that is, equivalent to the above pulse signal attenuation rate), and the corresponding formula is:

In the formula, p and q are variables, which can represent h or v respectively, so Y _pq can represent any one of Y _hh , Y _hv , Y _vh , and Y _vv ; i is an integer greater than or equal to 1, representing the sequence of records number; ΔY _pq is the pulse compression signal attenuation rate of two adjacent pulse compression signals to be calculated. Since p and q are variables, they can represent h or v respectively, so ΔY _pq can represent ΔY _hh , ΔY _hv , ΔY _vh , Any of ΔY _vv .

Then, according to formulas (3) and (4), the following amplitude-phase balance algorithm model for calculating the amplitude-phase balance value between the polarization channels in the polarization active scaler is obtained, and the amplitude-phase balance algorithm model corresponds to The expression is shown in (5):

In the formula, p and q are variables, which can represent h or v respectively, so ΔY _pq represents any one of ΔY _hh , ΔY _hv , ΔY _vh , and ΔY _vv ; i is an integer greater than or equal to 1, representing the serial number of the record .

It can be known from formulas (3)-(5) that the attenuation rate of the pulse signal corresponding to each polarization channel can be obtained by comparing the amplitude and phase eigenvalues corresponding to two adjacent pulse compressed signals. Based on the attenuation rate of the pulse signal corresponding to the preset reference polarization channel, by comparing the relationship between the attenuation rate of the pulse signal between each polarization channel and the reference polarization channel, the polarization active fixed channel can be obtained. The amplitude and phase balance value between the polarization channels in the scaler can be used to realize the calibration of the amplitude and phase balance of the polarization active scaler.

Step 104 : calibrating the polarization channel in the polarization active scaler based on the amplitude-phase balance value. Wherein, the polarization channels include hh polarization channels, HV polarization channels, vh polarization channels and vv polarization channels.

Specifically, the hh polarization channel in the polarization active scaler may be calibrated based on the amplitude and phase balance value of the hh polarization channel relative to the reference polarization channel; based on the hv pole The amplitude and phase balance of the polarization channel relative to the reference polarization channel is used to calibrate the hv polarization channel in the polarization active scaler; based on the vh polarization channel relative to the reference polarization The amplitude and phase balance value of the channel is used to calibrate the vh polarization channel in the polarization active scaler; based on the amplitude and phase balance value of the vv polarization channel relative to the reference polarization channel, the The vv polarization channel in the polarization active scaler is calibrated. The reference polarization channel may be one of the hh polarization channel, the hv polarization channel, the vh polarization channel, and the vv polarization channel, which is not specifically limited herein.

By using the method for calibrating the channel balance of the polarization active scaler according to the embodiment of the present invention, it is possible to realize the accurate calibration of the amplitude and phase balance between the polarization channels of the polarization active scaler as a whole, without the need for The complex and high-precision signal measuring instrument reduces the cost and improves the stability of the calibration of the amplitude and phase balance.

Corresponding to the method for calibrating the channel balance of the polarization active scaler provided above, the present invention also provides a device for calibrating the channel balance of the polarization active scaler. Since the embodiment of the device is similar to the above method embodiment, the description is relatively simple. For related details, please refer to the description of the above method embodiment part. The following describes the calibration of the channel balance of the polarized active scaler. The embodiments of the apparatus are merely illustrative. Please refer to FIG. 4 , which is a schematic structural diagram of an apparatus for calibrating the channel balance of a polarized active scaler according to an embodiment of the present invention.

The device for calibrating the channel balance of a polarization active scaler according to the present invention specifically includes the following parts:

The pulse signal attenuation rate obtaining unit 401 is configured to perform matched filtering processing on the chirp signal corresponding to each polarization channel in the polarization active scaler to obtain a pulse compressed signal; perform interpolation processing on the pulse compressed signal, Extracting the amplitude and phase at the peak of the pulse compressed signal to obtain the amplitude and phase eigenvalues; comparing the amplitude and phase eigenvalues corresponding to two adjacent pulse compressed signals to obtain the pulse signal attenuation rate corresponding to each polarization channel.

The pulse signal attenuation rate obtaining unit 402 is configured to compare the amplitude and phase characteristic values corresponding to two adjacent pulse compression signals to obtain the pulse signal attenuation rate corresponding to each polarization channel.

The amplitude-phase balance value obtaining unit 403 is configured to use the preset reference polarization channel attenuation rate of the pulse signal as a reference, and compare the relationship between the pulse signal attenuation rate between each polarization channel and the reference polarization channel, Obtain the value of the amplitude and phase balance between the polarization channels in the polarization active scaler.

The polarization channel calibration unit 404 is configured to calibrate the polarization channel in the polarization active scaler based on the amplitude-phase balance value.

By using the device for calibrating the channel balance of the polarization active scaler according to the embodiment of the present invention, it is possible to realize the accurate calibration of the amplitude and phase balance between the polarization channels of the polarization active scaler as a whole, without the need for The complex and high-precision signal measuring instrument reduces the cost and improves the stability of the calibration of the amplitude and phase balance.

As shown in FIG. 2, the present invention also provides a calibration device for a polarized active scaler, including: a pointing adjustment device 201 and a corner reflector 202; the pointing adjustment device 201 is used to control the angle The direction of the reflector 202; the corner reflector 202 is used to reflect back the chirp signal emitted by the transmitting antenna of the polarized active scaler. Wherein, none of the four elements of the polarization scattering characteristic matrix corresponding to the corner reflector 202 is zero. Specifically, the corner reflector 202 includes, but is not limited to, a dihedral corner reflector using a preset polarization rotation angle, and the like. Wherein, the preset polarization rotation angle of the dihedral angle reflector may be ±22.5°, ±67.5°, ±112.5°, or ±157.5°.

中的四个元素均不为零即可，在此不做具体限定。Of course, in the specific implementation process, other types of corner reflectors can also be used to satisfy the polarization scattering matrix.

It is only necessary that the four elements in are not zero, which is not specifically limited here.

Corresponding to the method for calibrating the channel balance of the polarization active scaler provided above, the present invention also provides an electronic device. Since the embodiment of the electronic device is similar to the above-mentioned method embodiment, the description is relatively simple. For related details, please refer to the description of the above-mentioned method embodiment part, and the electronic device described below is only illustrative. As shown in FIG. 5 , it is a schematic diagram of a physical structure of an electronic device disclosed in an embodiment of the present invention. The electronic device may include: a processor 501 , a memory 502 and a communication bus 503 , wherein the processor 501 and the memory 502 communicate with each other through the communication bus 503 . The processor 501 can invoke the logic instructions in the memory 502 to execute a method for calibrating the channel balance of the polarimetric active scaler, the method comprising: performing experimentally recording on each polarimetric channel in the polarimetric active scaler; The chirp signal is subjected to matched filtering processing to obtain a pulse compressed signal; the pulse compressed signal is subjected to interpolation processing to extract the amplitude and phase at the peak of the pulse compressed signal to obtain the amplitude and phase characteristic values; two adjacent pulses are compressed The amplitude and phase characteristic values corresponding to the signals are compared to obtain the pulse signal attenuation rate corresponding to each polarization channel; based on the pulse signal attenuation rate of the preset reference polarization channel, by comparing each polarization channel relative to the reference The relationship between the pulse signal attenuation rates between the polarization channels, the amplitude and phase balance value between the polarization channels in the polarization active scaler is obtained; The polarization channel is calibrated.

In addition, the above-mentioned logic instructions in the memory 502 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, Read-Only Memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes .

On the other hand, an embodiment of the present invention also provides a computer program product, the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program includes program instructions, when the program instructions When executed by the computer, the computer can execute the method for calibrating the channel balance of the polarization active scaler provided by the above method embodiments. The method includes: experimenting on each polarization channel in the polarization active scaler. The recorded chirp signal is subjected to matched filtering processing to obtain a pulse compressed signal; interpolation processing is performed on the pulse compressed signal to extract the amplitude and phase at the peak of the pulse compressed signal to obtain the amplitude and phase characteristic values; Compare the amplitude and phase eigenvalues corresponding to the pulse compression signal to obtain the pulse signal attenuation rate corresponding to each polarization channel; The relationship of the pulse signal attenuation rate between the reference polarization channels is obtained, and the amplitude-phase balance value between the polarization channels in the polarization active scaler is obtained; based on the amplitude-phase balance value, the polarization active calibration is performed The polarization channel in the detector is calibrated.

In yet another aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, is implemented to execute the polarized active determinator provided by the foregoing embodiments. A method for calibrating the balance of a scaler channel, the method comprising: performing matched filtering processing on the chirp signal experimentally recorded by each polarization channel in a polarization active scaler to obtain a pulse compression signal; The signal is subjected to interpolation processing, and the amplitude and phase at the peak of the pulse compressed signal are extracted to obtain the amplitude and phase eigenvalues; the amplitude and phase eigenvalues corresponding to two adjacent pulse compressed signals are compared to obtain the pulse corresponding to each polarization channel. Signal attenuation rate; based on the pulse signal attenuation rate of the preset reference polarization channel, the polarization active channel is obtained by comparing the relationship between the pulse signal attenuation rate between each polarization channel and the reference polarization channel. The amplitude-phase balance value between the polarization channels in the scaler; the polarization channel in the polarization active scaler is calibrated based on the amplitude-phase balance value.

The device embodiments described above are only illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in One place, or it can be distributed over multiple network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment. Those of ordinary skill in the art can understand and implement it without creative effort.

From the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and certainly can also be implemented by hardware. Based on this understanding, the above-mentioned technical solutions can be embodied in the form of software products in essence or the parts that make contributions to the prior art, and the computer software products can be stored in computer-readable storage media, such as ROM/RAM, magnetic A disc, an optical disc, etc., includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments or some parts of the embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A method for calibrating channel balance of a polarized active scaler, comprising:

performing matched filtering processing on the linear frequency modulation pulse signal corresponding to each polarization channel in the polarization active scaler to obtain a pulse compression signal; performing interpolation processing on the pulse compression signal, and extracting the amplitude and the phase at the peak value of the pulse compression signal to obtain an amplitude-phase characteristic value;

comparing the amplitude-phase characteristic values corresponding to two adjacent pulse compression signals to obtain the pulse signal attenuation rate corresponding to each polarization channel;

obtaining an amplitude-phase balance value between polarization channels in the polarization active scaler by comparing the relation of the pulse signal attenuation rate between each polarization channel and the reference polarization channel by taking the preset pulse signal attenuation rate of the reference polarization channel as a reference;

and calibrating a polarization channel in the polarization active scaler based on the amplitude-phase balance value.

2. The calibration method for polarization active scaler channel balance of claim 1, wherein said polarization channels comprise hh polarization channel, hv polarization channel, vh polarization channel and vv polarization channel;

the reference polarization channel is one of the hh polarization channel, the hv polarization channel, the vh polarization channel, and the vv polarization channel.

3. The calibration method for calibrating channel balance of the polarization active scaler according to claim 2, wherein the calibrating the polarization channel in the polarization active scaler based on the magnitude-phase balance value specifically comprises:

calibrating the hh polarization channel in the polarization active scaler based on the amplitude-phase balance value of the hh polarization channel relative to the reference polarization channel;

calibrating the hv polarization channel in the polarization active scaler based on the amplitude-phase balance value of the hv polarization channel relative to the reference polarization channel;

calibrating a vh polarization channel in the polarization active scaler based on the amplitude-phase balance value of the vh polarization channel relative to the reference polarization channel;

and calibrating the vv polarization channel in the polarization active scaler based on the amplitude-phase balance value of the vv polarization channel relative to the reference polarization channel.

4. The method of calibrating polarization active scaler channel balance of claim 1, further comprising: if the polarization scattering matrix of the polarization active scaler is

The polarization scattering matrix of the standard reflector corresponding to the polarization active scaler is

The distance between the polarized active scaler and the standard reflector is R; the active scaler comprises a p receiving q transmitting channel which is marked as a pq channel; let the 1 st recorded chirp signal be

The 2 nd recorded chirp signal is

By analogy, the ith recorded linear frequency modulation signal is obtained

Then the expression corresponding to the pulse signal attenuation rate is:

wherein λ is a signal wavelength, the signal being a chirp signal; i is an integer greater than or equal to 1 and represents the serial number of the record; r is the distance between the polarized active scaler and the standard reflector; p and q are both variables, representing h or v, respectively;

recording the ith linear frequency modulation pulse signal of the pq channel;

recording a linear frequency modulation pulse signal for the (i + 1) th time of the pq channel; the pq channel is any one of an hh channel, an hv channel, a vh channel and a vv channel; s_pqS in a polarization scattering matrix representing said polarization active scaler_hh、S_hv、S_vh、S_vvAny one of the above;

is a known quantity as a reference, representing the polarization scattering matrix of the standard reflector

Any one of them.

5. The calibration method for the channel balance of the active polarization scaler according to claim 4, wherein the chirp signal corresponding to each polarization channel in the active polarization scaler is subjected to matched filtering to obtain a pulse compression signal; performing interpolation processing on the pulse compression signal, and extracting the amplitude and the phase at the peak value of the pulse compression signal to obtain an amplitude-phase characteristic value, which specifically comprises the following steps:

chirp signal to polarization channel in said polarization active scaler recorded twice next to each other

And

performing matched filtering processing to obtain a pulse compression signal; performing interpolation processing on the pulse compression signal, extracting amplitude-phase data of the peak value of the pulse compression signal, and obtaining an amplitude-phase characteristic value

And

the method for comparing the amplitude-phase characteristic values corresponding to two adjacent pulse compression signals to obtain the pulse signal attenuation rate corresponding to each polarization channel specifically comprises the following steps:

comparing the amplitude-phase characteristic values corresponding to two adjacent pulse compression signals to obtain the pulse compression signal attenuation rate corresponding to each polarization channel, wherein the corresponding formula is as follows:

wherein p and q are variables which can represent h or v, respectively; y is_pqRepresents Y_hh、Y_hv、Y_vh、Y_vvAny one of the above; i is an integer greater than or equal to 1 and represents the serial number of the record; delta Y_pqFor the pulse compression signal attenuation rates of two adjacent pulse compression signals to be calculated, since p and q are variables respectively representing h or v, Δ Y_pqRepresents DeltaY_hh、ΔY_hv、ΔY_vh、ΔY_vvAny one of the above; wherein, Delta Y_hhAttenuation ratio of pulse compression signal, Δ Y, for hh channel_hvDecay Rate, Δ Y, of pulse compression Signal for hv channel_vhPulse compression signal attenuation Rate, Δ Y, for vh channel_vvThe pulse compression signal attenuation rate for the vv channel; the pulse compression signal attenuation rate corresponds to the pulse signal attenuation rate.

6. A calibration apparatus for polarization active scaler channel balance, comprising:

the pulse signal attenuation rate obtaining unit is used for performing matched filtering processing on the linear frequency modulation pulse signal corresponding to each polarization channel in the polarization active scaler to obtain a pulse compression signal; performing interpolation processing on the pulse compression signal, and extracting the amplitude and the phase at the peak value of the pulse compression signal to obtain an amplitude-phase characteristic value;

the pulse signal attenuation rate obtaining unit is used for comparing amplitude-phase characteristic values corresponding to two adjacent pulse compression signals to obtain a pulse signal attenuation rate corresponding to each polarization channel;

the amplitude-phase balance value obtaining unit is used for obtaining an amplitude-phase balance value between the polarized channels in the polarized active scaler by comparing the relation of the pulse signal attenuation rate between each polarized channel and the reference polarized channel with the pulse signal attenuation rate of a preset reference polarized channel as a reference;

and the polarization channel calibration unit is used for calibrating the polarization channel in the polarization active scaler based on the amplitude-phase balance value.

7. A calibration apparatus for a polar active scaler, comprising: a pointing adjustment device and a corner reflector;

the direction adjusting device is used for controlling the direction of the corner reflector;

the corner reflector is used for reflecting the linear frequency modulation pulse signal transmitted by the transmitting antenna of the polarization active scaler back; and four elements of the polarization scattering characteristic matrix corresponding to the corner reflector are not zero.

8. Calibration apparatus for a polarization active sealer according to claim 7, wherein said corner reflector is a dihedral corner reflector employing a preset polarization rotation angle.

9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program performs the steps of the calibration method of polarization active scaler channel balance according to any of the claims 1 to 5.

10. A non-transitory computer readable storage medium, having stored thereon a computer program, which, when being executed by a processor, carries out the steps of the calibration method of polarization active scaler channel balancing according to any one of claims 1 to 5.

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