CN114791600A - Secondary radar receiving signal direction judgment method and device - Google Patents

Abstract

In order to solve the problem that performance of an indicator F is affected and deteriorated by device performance in the conventional method for judging the direction of a secondary radar received signal relative to a beam normal, an embodiment of the invention provides a method and a device for judging the direction of a secondary radar received signal, wherein the method comprises the following steps: sampling the intermediate frequency signals of the sigma channel and the delta channel, and converting each intermediate frequency signal from an analog signal into a discrete digital signal; carrying out orthogonal decomposition on the sigma-channel intermediate frequency signal and the delta-channel intermediate frequency signal by using a local oscillation signal with the same frequency as the intermediate frequency signal to generate a zero intermediate frequency I signal sequence S of the sigma-channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ And generating a zero intermediate frequency I signal sequence S of the delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ (ii) a Calculating S in a signal sequence _ΣI And S _ΔQ Sum of sum S _ΣQ And S _ΔI Product of (d); according to S _ΣI And S _ΔQ Sum of sum S _ΣQ And S _ΔI The product of the two signals is used for judging the secondary radar receiving signal direction of the current point. The embodiment of the invention realizes the judgment of the secondary radar receiving signal direction.

Description

Secondary radar received signal direction judgment method and device

Technical Field

The invention relates to a method and a device for judging the direction of a secondary radar receiving signal.

Background

The Secondary Surveillance Radar (SSR) realizes the positioning of the target by processing the response signal of the aerial flight target and provides the airspace traffic situation information for the controller.

The monopulse secondary radar antenna has three signal channels, namely a sigma channel, a delta channel and an omega channel, the secondary radar receives a secondary radar echo signal of the aerial airplane through the antenna of the secondary radar, the secondary radar forms three paths of video signals of the sigma channel, the delta channel and the omega channel respectively after filtering, amplifying and wave detecting processing, and the secondary radar receives the signal processing as shown in fig. 1. The secondary radar uses a sigma/delta antenna to realize angle measurement, and the vector synthesis of received signals of the sigma/delta antenna is as shown in fig. 2, when the signals are from the left side of the normal, the sigma channel and delta channel signals are different in phase by pi/2, and when the signals are from the right side of the normal, the sigma channel and delta channel signals are different in phase by-pi/2.

The signal processing module performs off-axis angle (OBA) calculation according to the amplitude difference of the sigma channel signal and the delta channel signal: firstly, the phase detector gives a left-right indication F (-/+) of the direction of the signal relative to the normal line of the wave beam according to the sigma/delta signal phase difference; then, difference calculation is carried out on the corresponding sigma signal and delta signal amplitude in the time domain, the relation between the sigma/delta signal and the OBA is shown in figure 3, and the target off-axis-of-view angle theta is obtained according to the difference _OBA (ii) a Finally, the angle value theta at the normal of the beam is indicated according to the direction ₀ Base plus or minus θ _OBA Obtaining a true angle theta of the signal, theta being theta ₀ ±θ _OBA 。

In the prior art, a method for judging the direction of a secondary radar receiving signal relative to a beam normal is realized by adopting a special hardware circuit. Firstly: the phase discriminator generates phase discrimination voltage V according to the phase difference of sigma/delta channel signals _P Then: circuit comparison V _P And a predetermined voltage V _S To give a signal direction left and right indication index F. The prior art has the following defects: 1. the analog circuit is easily influenced by environmental temperature change and device performance attenuation, the index F changes, and regular calibration is needed; 2. the life problem exists due to the attenuation and aging of the analog device; 3. when the analog device is in weak signal, the performance is greatly influenced by noise, the direction judgment fuzzy area is large, and the system is influencedAnd (4) performance.

Disclosure of Invention

In order to solve the problem that performance of the receiver is affected and deteriorated by the performance of the indicator F in the conventional method for judging the direction of a secondary radar received signal relative to a beam normal, the embodiment of the invention provides a method and a device for judging the direction of a secondary radar received signal.

The embodiment of the invention is realized by the following technical scheme:

in a first aspect, an embodiment of the present invention provides a method for determining a direction of a secondary radar received signal, including:

sampling the intermediate frequency signals of the sigma channel and the delta channel, and converting each intermediate frequency signal from an analog signal into a discrete digital signal;

carrying out orthogonal decomposition on the sigma-channel intermediate frequency signal and the delta-channel intermediate frequency signal by using a local oscillation signal with the same frequency as the intermediate frequency signal to generate a zero intermediate frequency I signal sequence S of the sigma-channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ And generating a zero intermediate frequency I signal sequence S of the delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ ；

Calculating S in a signal sequence _ΣI And S _ΔQ Sum of sum S _ΣQ And S _ΔI The product of (a);

according to S _ΣI And S _ΔQ Sum of sums of S _ΣQ And S _ΔI The product of (a) and (b) determines the secondary radar received signal direction at the current point.

Further, according to S _ΣI And S _ΔQ Sum of sum S _ΣQ And S _ΔI Judging the secondary radar receiving signal direction of the current point; the method comprises the following steps:

judging S of the current point _ΣI And S _ΔQ Whether the absolute value of the product of (a) is greater than S _ΣQ And S _ΔI If the absolute value of the product of (1) is S _ΣI And S _ΔQ The sign of the product of (1) determines the secondary radar receiving signal direction of the current point; if not, the step S is carried out _ΣQ And S _ΔI The sign of the product of (a) determines the secondary radar reception signal direction at the current point.

Further, each intermediate frequency signal converted into a discrete digital signal is expressed by the following equation:

the sigma-channel signal: s _Σ (t)＝cos(ωt) (1)

Δ channel signal left of beam normal: s _ΔL (t)＝cos(ωt-π/2) (2)

Δ channel signal to the right of the beam normal: s. the _ΔR (t)＝cos(ωt+π/2) (3)

Where ω is the carrier frequency and t is time.

Further, zero intermediate frequency I signal sequence S of sigma channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ The following formula is adopted:

sigma-channel I signal: s. the _ΣI (t)＝cos(ωt)×cos(ωt) (4)

Sigma-channel Q signal: s _ΣQ (t)＝cos(ωt)×cos(ωt+π/2) (5)

Zero intermediate frequency I signal sequence S of delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ The following formula is adopted:

Δ channel I signal left of beam normal: s. the _ΔLI (t)＝cos(ωt-π/2)×cos(ωt) (6)

Δ channel Q signal to the left of beam normal: s. the _ΔLQ (t)＝cos(ωt-π/2)×cos(ωt+π/2) (7)

Δ channel I signal to the right of the beam normal: s. the _ΔRI (t)＝cos(ωt+π/2)×cos(ωt) (8)

Δ channel Q signal to the right of the beam normal: s _ΔRQ (t)＝cos(ωt+π/2)×cos(ωt+π/2) (9)

Where ω is the carrier frequency and t is time.

Further, S _ΣI And S _ΔQ Product of (A) is S _ΣI (t)×S _ΔQ (t)；S _ΣQ And S _ΔI Product of (A) is S _ΣQ (t)×S _ΔI (t)。

In a second aspect, an embodiment of the present invention provides a secondary radar received signal direction determining apparatus, including:

the analog-to-digital conversion unit is used for sampling the intermediate frequency signals of the sigma channel and the delta channel and converting the intermediate frequency signals from analog signals to discrete digital signals;

a signal decomposition unit for performing orthogonal decomposition on the sigma-channel intermediate frequency signal and the delta-channel intermediate frequency signal by using a local oscillator signal having the same frequency as the intermediate frequency signal to generate a zero intermediate frequency I signal sequence S of the sigma-channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ And generating a zero intermediate frequency I signal sequence S of the delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ ；

A calculation unit for calculating S in the signal sequence _ΣI And S _ΔQ Sum of sums of S _ΣQ And S _ΔI Product of (d);

a determination unit for determining based on S _ΣI And S _ΔQ Sum of sums of S _ΣQ And S _ΔI The product of the two signals is used for judging the secondary radar receiving signal direction of the current point.

Further, a judging unit for judging S of the current point _ΣI And S _ΔQ Whether the absolute value of the product of (b) is greater than S _ΣQ And S _ΔI If the absolute value of the product of (1) is S _ΣI And S _ΔQ The sign of the product of (1) determines the secondary radar receiving signal direction of the current point; if not, then S is used _ΣQ And S _ΔI The sign of the product of (a) determines the secondary radar reception signal direction at the current point.

Further, the analog-to-digital conversion unit is configured to convert each intermediate frequency signal into a discrete digital signal represented by the following formula:

the sigma-channel signal: s _Σ (t)＝cos(ωt) (1)

Δ channel signal to the left of beam normal: s. the _ΔL (t)＝cos(ωt-π/2) (2)

Δ channel signal to the right of the beam normal: s _ΔR (t)＝cos(ωt+π/2) (3)

Where ω is the carrier frequency and t is time.

Further, the signal decomposition unit is configured to orthogonally decompose the Σ channel intermediate frequency signal and the Δ channel intermediate frequency signal into:

the zero intermediate frequency I signal sequence S of the sigma channel is expressed by the following formula _ΣI And zero intermediate frequency Q signal sequence S _ΣQ ：

Sigma-channel I signal: s _ΣI (t)＝cos(ωt)×cos(ωt) (4)

Sigma-channel Q signal: s _ΣQ (t)＝cos(ωt)×cos(ωt+π/2) (5)

Zero intermediate frequency I signal sequence S of sigma delta channel expressed by the following formula _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ ：

Δ channel I signal left of beam normal: s. the _ΔLI (t)＝cos(ωt-π/2)×cos(ωt) (6)

Δ channel Q signal to the left of beam normal: s. the _ΔLQ (t)＝cos(ωt-π/2)×cos(ωt+π/2) (7)

Δ channel I signal to the right of the beam normal: s. the _ΔRI (t)＝cos(ωt+π/2)×cos(ωt) (8)

Δ channel Q signal to the right of beam normal: s. the _ΔRQ (t)＝cos(ωt+π/2)×cos(ωt+π/2) (9)

Where ω is the carrier frequency and t is time.

Further, the signal decomposition unit is a DDC controller.

Compared with the prior art, the embodiment of the invention has the following advantages and beneficial effects:

according to the method and the device for judging the direction of the secondary radar receiving signal, based on the method program or a hardware system capable of realizing the corresponding method program, the judgment of the direction of the secondary radar receiving signal is realized through signal sampling analog-to-digital conversion, signal decomposition processing and signal direction judgment, and the defect that the prior art is easily influenced by environmental temperature change and device performance when an analog circuit is adopted for judging the direction of the secondary radar receiving signal is overcome.

Drawings

In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings that are required in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and that those skilled in the art may also derive other related drawings based on these drawings without inventive effort.

Fig. 1 is a block diagram of a conventional secondary radar reception signal processing.

Fig. 2 is a vector relationship diagram of the Σ antenna signal and the Δ antenna signal.

Fig. 3 is a graph of the relationship between the Σ signal, the Δ signal, and the OBA.

Fig. 4 is a schematic flow chart of a secondary radar received signal direction determination method.

Fig. 5 is a schematic diagram of a signal processing flow.

Fig. 6 is a schematic diagram of a secondary radar received signal direction determination device based on component cross equalization.

Fig. 7 is a schematic structural diagram of a secondary radar received signal direction determination device.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and the accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not used as limiting the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that: it is not necessary to employ these specific details to practice the present invention. In other instances, well-known structures, circuits, materials, or methods have not been described in detail in order to avoid obscuring the present invention.

Throughout the specification, reference to "one embodiment," "an embodiment," "one example," or "an example" means: the particular features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment of the invention. Thus, the appearances of the phrases "one embodiment," "an embodiment," "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. Further, those of ordinary skill in the art will appreciate that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the description of the present invention, the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "upper", "lower", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, merely for convenience of description and simplification of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore, should not be construed as limiting the scope of the invention.

Examples

In order to solve the problem that performance of the receiver is affected and deteriorated by the performance of the indicator F in the conventional method for determining the direction of a secondary radar received signal relative to a beam normal, in a first aspect, an embodiment of the present invention provides a method for determining the direction of a secondary radar received signal, which is shown in fig. 4 to 5 and includes:

s1, sampling intermediate frequency signals of a sigma channel and a delta channel, and converting the intermediate frequency signals from analog signals into discrete digital signals;

s2, carrying out orthogonal decomposition on the sigma-channel intermediate frequency signal and the delta-channel intermediate frequency signal by using a local oscillator signal with the same frequency as the intermediate frequency signal to generate a zero intermediate frequency I signal sequence S of the sigma-channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ And generating a zero intermediate frequency I signal sequence S of the delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ ；

S3, calculating S in the signal sequence _ΣI And S _ΔQ Sum of sum S _ΣQ And S _ΔI The product of (a);

s4. according to S _ΣI And S _ΔQ Sum of sums of S _ΣQ And S _ΔI Product of (2) judgingAnd cutting off the signal receiving direction of the secondary radar at the current point.

Therefore, the embodiment of the invention realizes the judgment of the direction of the secondary radar receiving signal through signal sampling analog-to-digital conversion, signal decomposition processing and signal direction judgment based on the method program, and avoids the defect that the prior art is easily influenced by the environmental temperature change and the device performance when an analog circuit is adopted to judge the direction of the secondary radar receiving signal.

The method for judging the direction of the secondary radar received signal is a method for judging the direction of the secondary radar received signal based on component cross equalization, and aims to solve the problems that a signal direction identification circuit in a secondary radar is easily affected by the attenuation of the environmental temperature and the performance of devices and the service life of a phase identification functional component.

Further, according to S _ΣI And S _ΔQ Sum of sums of S _ΣQ And S _ΔI Judging the secondary radar receiving signal direction of the current point; the method comprises the following steps:

judging S of the current point _ΣI And S _ΔQ Whether the absolute value of the product of (a) is greater than S _ΣQ And S _ΔI If the absolute value of the product of (1) is S _ΣI And S _ΔQ The sign of the product of (1) determines the secondary radar receiving signal direction of the current point; if not, then S is used _ΣQ And S _ΔI The sign of the product of (a) determines the secondary radar reception signal direction at the current point.

Selecting the cross product of the signal components (i.e., S) in the sample sequence _ΣI (t)×S _ΔQ (t)、S _ΣQ (t)×S _ΔI (t)) the sign of the term with large absolute value determines the signal direction F of the current point, thus being equivalent to selecting I, Q signal pairs with more balanced components, avoiding signal pairs with low single-path components, and avoiding the influence of noise on the signal direction F judgment.

Further, each intermediate frequency signal converted into a discrete digital signal is expressed by the following equation:

the sigma-channel signal: s _Σ (t)＝cos(ωt) (1)

Δ channel signal left of beam normal: s. the _ΔL (t)＝cos(ωt-π/2) (2)

Δ channel signal to the right of the beam normal: s. the _ΔR (t)＝cos(ωt+π/2) (3)

Where ω is the carrier frequency and t is time.

Further, zero intermediate frequency I signal sequence S of sigma channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ The following formula is adopted:

sigma-channel I signal: s. the _ΣI (t)＝cos(ωt)×cos(ωt) (4)

Sigma-channel Q signal: s. the _ΣQ (t)＝cos(ωt)×cos(ωt+π/2) (5)

Zero intermediate frequency I signal sequence S of delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ The following formula is adopted:

Δ channel I signal left of beam normal: s _ΔLI (t)＝cos(ωt-π/2)×cos(ωt) (6)

Δ channel Q signal to the left of beam normal: s _ΔLQ (t)＝cos(ωt-π/2)×cos(ωt+π/2) (7)

Δ channel I signal to the right of the beam normal: s _ΔRI (t)＝cos(ωt+π/2)×cos(ωt) (8)

Δ channel Q signal to the right of the beam normal: s. the _ΔRQ (t)＝cos(ωt+π/2)×cos(ωt+π/2) (9)

Where ω is the carrier frequency and t is time.

Further, S _ΣI And S _ΔQ Product of (S) _ΣI (t)×S _ΔQ (t)；S _ΣQ And S _ΔI Product of (S) _ΣQ (t)×S _ΔI (t)。

The signal processing flow is shown with reference to fig. 5. Specifically, the method comprises the following steps:

signal sampling: the intermediate frequency signals of the sigma channel and the delta channel are respectively sampled from an intermediate frequency output point of the secondary radar receiver, and are converted from analog signals into discrete digital signals. The signal expression is shown in equations 1-3, where carrier frequency is represented and t is time.

The sigma-channel signal: s. the _Σ (t)＝cos(ωt) (1)

Δ channel signal left of beam normal: s. the _ΔL (t)＝cos(ωt-π/2) (2)

Δ channel signal to the right of the beam normal: s. the _ΔR (t)＝cos(ωt+π/2) (3)

Orthogonal decomposition down-conversion: and performing orthogonal decomposition on the sigma-delta channel intermediate frequency signals by using local oscillation signals with the same frequency as the intermediate frequency signals to generate zero intermediate frequency I, Q signals of the sigma-delta channel and the delta channel respectively, wherein the signal expression is shown in formulas 4 to 9.

Sigma-channel I signal: s. the _ΣI (t)＝cos(ωt)×cos(ωt) (4)

Sigma-channel Q signal: s. the _ΣQ (t)＝cos(ωt)×cos(ωt+π/2) (5)

Δ channel I signal to the left of the beam normal: s _ΔLI (t)＝cos(ωt-π/2)×cos(ωt) (6)

Δ channel Q signal left of beam normal: s _ΔLQ (t)＝cos(ωt-π/2)×cos(ωt+π/2) (7)

Δ channel I signal to the right of the beam normal: s _ΔRI (t)＝cos(ωt+π/2)×cos(ωt) (8)

Δ channel Q signal to the right of beam normal: s. the _ΔRQ (t)＝cos(ωt+π/2)×cos(ωt+π/2) (9)

And (3) direction judgment: the positive and negative laws of the sampling values of each path of signal when the phase changes from 0 to 2 pi can be obtained by analyzing the formulas 4 to 9, and are shown in table 1.

TABLE 1 Positive and negative law of signal sampling values

The following rules can be summarized from the rules of table 1:

S _ΣI (t)×S _ΔQ (t)<0 and S _ΣQ (t)×S _ΔI (t)<0, then the signal is left of the normal, F (t) is "-";

S _ΣI (t)×S _ΔQ (t)>0 and S _ΣQ (t)×S _ΔI (t)>0, the signal is to the right of the normal, and F (t) is "+".

The signals are preferably: because of different initial phases, corresponding phases of each path of IQ signal components have different amplitude distributions, a channel in an actual operation system has noise, and when the amplitude of a certain path of signal component is close to the amplitude of the noise, the signal component is superposed with the noise, and the positive and negative values of the signal component are influenced.

For this case, the cross product of the signal components (i.e., S) in the sample sequence is selected _ΣI (t)×S _ΔQ (t)、S _ΣQ (t)×S _ΔI (t)) the sign of the term with large absolute value determines the signal direction F of the current point, thus being equivalent to selecting I, Q signal pairs with more balanced components, avoiding signal pairs with low single-path components, and avoiding the influence of noise on the direction F judgment.

The secondary radar receiving signal direction judgment module based on component cross equalization is used for replacing an original system analog channel phase discrimination circuit, the module processing logic is shown in fig. 5, and the specific application implementation mode is as follows:

1) signal leading: leading sigma and delta channel signals from a frequency point of the secondary radar receiver;

2) signal sampling: respectively sampling the intermediate frequency signals of the sigma channel and the delta channel through an analog-to-digital conversion circuit, and converting the analog signals into digital signals;

3) signal processing: down-conversion and orthogonal decomposition are carried out on the digital signal sampled in the step 2) to generate I/Q signal sequences (S) of sigma-delta channels and delta channels respectively _ΣI 、S _ΣQ 、S _ΔI 、S _ΔQ )；

4) Signal preferred direction determination: selecting S in a signal sequence _ΣI (t)×S _ΔQ (t)、S _ΣQ (t)×S _ΔI (t) the term with the larger absolute value of the product determines the signal direction F (t) for the current point.

The method for judging the direction of the secondary radar receiving signal is based on the digital software processing, the processing module has no problem that the performance is influenced by the attenuation of devices, the periodical calibration is not needed, and the service life is longer; the direction is preferably determined based on the signal, and the direction determination is more accurate when the signal is weak.

In a second aspect, an embodiment of the present invention provides a secondary radar received signal direction determining apparatus, shown in fig. 6 to 7, including:

the analog-to-digital conversion unit is used for sampling the intermediate frequency signals of the sigma channel and the delta channel and converting the intermediate frequency signals from analog signals to discrete digital signals;

a signal decomposition unit for performing orthogonal decomposition on the sigma-channel intermediate frequency signal and the delta-channel intermediate frequency signal by using a local oscillator signal having the same frequency as the intermediate frequency signal to generate a zero intermediate frequency I signal sequence S of the sigma-channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ And generating a zero intermediate frequency I signal sequence S of the delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ ；

A calculation unit for calculating S in the signal sequence _ΣI And S _ΔQ Sum of sums of S _ΣQ And S _ΔI Product of (d);

a determination unit for determining based on S _ΣI And S _ΔQ Sum of sums of S _ΣQ And S _ΔI The product of the two signals is used for judging the secondary radar receiving signal direction of the current point.

Therefore, the embodiment of the invention realizes the judgment of the secondary radar receiving signal direction through signal sampling analog-to-digital conversion, signal decomposition processing and signal direction judgment based on a hardware system capable of realizing the corresponding method program, and avoids the defect that the prior art is easily influenced by the environmental temperature change and the device performance when an analog circuit is adopted to judge the secondary radar receiving signal direction.

Further, a judging unit for judging S of the current point _ΣI And S _ΔQ Whether the absolute value of the product of (a) is greater than S _ΣQ And S _ΔI If the absolute value of the product of (1) is S _ΣI And S _ΔQ The sign of the product of the two-dimensional radar signal direction and the signal direction is judged; if not, the step S is carried out _ΣQ And S _ΔI The sign of the product of (a) determines the secondary radar reception signal direction at the current point.

Further, the analog-to-digital conversion unit is configured to convert each intermediate frequency signal into a discrete digital signal represented by the following formula:

the sigma-channel signal: s. the _Σ (t)＝cos(ωt) (1)

Δ channel signal to the left of beam normal: s. the _ΔL (t)＝cos(ωt-π/2) (2)

Δ channel signal to the right of the beam normal: s. the _ΔR (t)＝cos(ωt+π/2) (3)

Where ω is the carrier frequency and t is time.

Further, the signal decomposition unit is configured to orthogonally decompose the Σ channel intermediate frequency signal and the Δ channel intermediate frequency signal into:

the zero intermediate frequency I signal sequence S of the sigma channel is expressed by the following formula _ΣI Zero intermediate frequency Q signal sequence S of sum-sigma channel _ΣQ ：

Sigma-channel I signal: s. the _ΣI (t)＝cos(ωt)×cos(ωt) (4)

Sigma-channel Q signal: s _ΣQ (t)＝cos(ωt)×cos(ωt+π/2) (5)

A zero intermediate frequency I signal sequence S of a channel delta expressed by the following formula _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ ：

Δ channel I signal to the left of the beam normal: s. the _ΔLI (t)＝cos(ωt-π/2)×cos(ωt) (6)

Δ channel Q signal to the left of beam normal: s. the _ΔLQ (t)＝cos(ωt-π/2)×cos(ωt+π/2) (7)

Δ channel I signal to the right of the beam normal: s. the _ΔRI (t)＝cos(ωt+π/2)×cos(ωt) (8)

Δ channel Q signal to the right of beam normal: s _ΔRQ (t)＝cos(ωt+π/2)×cos(ωt+π/2) (9)

Where ω is the carrier frequency and t is time.

Further, the signal decomposition unit is a DDC controller.

The implementation principle of the secondary radar signal receiving direction judgment device refers to the above method, which is not described herein again.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only examples of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. A secondary radar received signal direction judgment method is characterized by comprising the following steps:

sampling the intermediate frequency signals of the sigma channel and the delta channel, and converting each intermediate frequency signal from an analog signal to a discrete digital signal;

carrying out orthogonal decomposition on the sigma-channel intermediate frequency signal and the delta-channel intermediate frequency signal by using a local oscillation signal with the same frequency as the intermediate frequency signal to generate a zero intermediate frequency I signal sequence S of the sigma-channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ And generating a zero intermediate frequency I signal sequence S of the delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ ；

Calculating S in a signal sequence _ΣI And S _ΔQ Sum of sums of S _ΣQ And S _ΔI Product of (d);

according to S _ΣI And S _ΔQ Sum of sums of S _ΣQ And S _ΔI The product of (a) and (b) determines the secondary radar received signal direction at the current point.

2. The secondary radar received signal direction determining method according to claim 1, wherein the secondary radar received signal direction determining method is based on S _ΣI And S _ΔQ Sum of sum S _ΣQ And S _ΔI Judging the secondary radar receiving signal direction of the current point; the method comprises the following steps:

judging S of the current point _ΣI And S _ΔQ Whether the absolute value of the product of (a) is greater than S _ΣQ And S _ΔI If the absolute value of the product of (1) is greater than the absolute value of the product of (1), the absolute value is S _ΣI And S _ΔQ The sign of the product of the two-dimensional radar signal direction and the signal direction is judged; if not, then S is used _ΣQ And S _ΔI The sign of the product of (a) determines the secondary radar reception signal direction at the current point.

3. The secondary radar received signal direction determining method according to claim 2, wherein each intermediate frequency signal converted into the discrete digital signal is expressed by the following equation:

the sigma-channel signal: s. the _Σ (t)＝cos(ωt) (1)

Δ channel signal to the left of beam normal: s _ΔL (t)＝cos(ωt-π/2) (2)

Δ channel signal to the right of the beam normal: s. the _ΔR (t)＝cos(ωt+π/2) (3)

Where ω is the carrier frequency and t is time.

4. The method as claimed in claim 3, wherein the zero-IF I signal sequence S of the sigma-delta channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ The following formula is adopted:

sigma-channel I signal: s _ΣI (t)＝cos(ωt)×cos(ωt) (4)

Sigma-channel Q signal: s. the _ΣQ (t)＝cos(ωt)×cos(ωt+π/2) (5)

Zero intermediate frequency I signal sequence S of delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ The following formula is adopted:

Δ channel I signal left of beam normal: s _ΔLI (t)＝cos(ωt-π/2)×cos(ωt) (6)

Δ channel Q signal to the left of beam normal: s _ΔLQ (t)＝cos(ωt-π/2)×cos(ωt+π/2) (7)

Δ channel I signal to the right of the beam normal: s. the _ΔRI (t)＝cos(ωt+π/2)×cos(ωt) (8)

Δ channel Q signal to the right of the beam normal: s _ΔRQ (t)＝cos(ωt+π/2)×cos(ωt+π/2) (9)

Where ω is the carrier frequency and t is time.

5. The secondary radar received signal direction determination method according to claim 4, wherein S is _ΣI And S _ΔQ Product of (A) is S _ΣI (t)×S _ΔQ (t)；S _ΣQ And S _ΔI Product of (A) is S _ΣQ (t)×S _ΔI (t)。

6. Secondary radar received signal direction judgement device, its characterized in that includes:

the analog-to-digital conversion unit is used for sampling the intermediate frequency signals of the sigma channel and the delta channel and converting the intermediate frequency signals from analog signals to discrete digital signals;

a signal decomposition unit for performing orthogonal decomposition on the sigma-channel intermediate frequency signal and the delta-channel intermediate frequency signal by using a local oscillator signal having the same frequency as the intermediate frequency signal to generate a zero intermediate frequency I signal sequence S of the sigma-channel _ΣI And zero intermediate frequency Q signal sequence S _ΣQ And generating a zero intermediate frequency I signal sequence S of the delta channel _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ ；

A calculation unit for calculating S in the signal sequence _ΣI And S _ΔQ Sum of sum S _ΣQ And S _ΔI Product of (d);

a determination unit for determining based on S _ΣI And S _ΔQ Sum of sum S _ΣQ And S _ΔI The product of (a) and (b) determines the secondary radar received signal direction at the current point.

7. The secondary radar received signal direction determination apparatus according to claim 6, wherein the determination unit is configured to determine S of the current point _ΣI And S _ΔQ Whether the absolute value of the product of (a) is greater than S _ΣQ And S _ΔI If the absolute value of the product of (1) is S _ΣI And S _ΔQ The sign of the product of (1) determines the secondary radar receiving signal direction of the current point; if not, then S is used _ΣQ And S _ΔI The sign of the product of (a) determines the secondary radar reception signal direction at the current point.

8. The secondary radar received signal direction determining apparatus according to claim 7, wherein the analog-to-digital converting unit is configured to convert each intermediate frequency signal into a discrete digital signal expressed by the following formula:

sigma channelSignal: s _Σ (t)＝cos(ωt) (1)

Δ channel signal left of beam normal: s. the _ΔL (t)＝cos(ωt-π/2) (2)

Δ channel signal to the right of the beam normal: s. the _ΔR (t)＝cos(ωt+π/2) (3)

Where ω is the carrier frequency and t is time.

9. The secondary radar received signal direction determining apparatus of claim 8, wherein the signal decomposition unit is configured to orthogonally decompose the Σ channel intermediate frequency signal and the Δ channel intermediate frequency signal into:

the zero intermediate frequency I signal sequence S of the sigma channel is expressed by the following formula _ΣI And zero intermediate frequency Q signal sequence S _ΣQ ：

Sigma-channel I signal: s. the _ΣI (t)＝cos(ωt)×cos(ωt) (4)

Sigma-channel Q signal: s. the _ΣQ (t)＝cos(ωt)×cos(ωt+π/2) (5)

The zero intermediate frequency I signal sequence S of the sigma delta channel is expressed by the following formula _ΔI Zero intermediate frequency Q signal sequence S of sum delta channel _ΔQ ：

Δ channel I signal left of beam normal: s _ΔLI (t)＝cos(ωt-π/2)×cos(ωt) (6)

Δ channel Q signal to the left of beam normal: s _ΔLQ (t)＝cos(ωt-π/2)×cos(ωt+π/2) (7)

Δ channel I signal to the right of the beam normal: s. the _ΔRI (t)＝cos(ωt+π/2)×cos(ωt) (8)

Δ channel Q signal to the right of the beam normal: s. the _ΔRQ (t)＝cos(ωt+π/2)×cos(ωt+π/2) (9)

Where ω is the carrier frequency and t is time.

10. The secondary radar received signal direction determining apparatus according to claim 9, wherein the signal decomposition unit is a DDC controller.

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