An active-passive integrated radar detection evaluation system

Abstract

This invention provides an integrated active and passive radar detection and evaluation system, comprising: an active radar system and a separate external radiation source system for transmitting and receiving, forming an integrated active and passive radar system; calculating the detection coverage area of ​​the integrated active and passive radar system; calculating the maximum detection range of the integrated active and passive radar system; normalization processing; an evaluation optimization model based on weighted factors; accurately calculating the detection coverage area of ​​the integrated active and passive radar system at different baseline distances, and the normalized processing model for the detection coverage area; accurately calculating the expression for the maximum detection range of the integrated active and passive radar system at different baseline distances, and the normalized processing model for the maximum detection range; and optimizing the deployment between the transmitting and receiving stations based on the evaluation optimization model with weighted factors, comprehensively considering both the detection coverage area and the maximum detection range.

Description

Technical Field

[0001] This invention relates to external radiation source radar, and more particularly to an integrated active and passive radar detection and evaluation system. Background Technology

[0002] Conventional radar systems have certain limitations in countering jamming, low-altitude / ultra-low-altitude penetration, stealth targets, and anti-radiation. Unlike conventional radar, external radiation source radars have separate transceiver stations, with the receiving station operating passively. They use electromagnetic signals emitted by a third-party non-cooperative radiation source to illuminate the target, while passively receiving the target's scattered signals, thus possessing excellent radar "four resistances" performance.

[0003] With the new demands placed on radar by electronic countermeasures, anti-radiation missiles, and stealth technology, the external illumination sources currently used by external radiation source radars mainly include: FM radio, analog television, digital broadcasting (DAB), terrestrial digital television (DVB-T), microwave wireless communication (GSM), wireless local area network (WLAN), long-term evolution of wireless communication (LTE), navigation and communication satellite signals, etc.

[0004] Because external radiation source radars have separate transmitting and receiving stations, their coverage area follows a Cassini oval. When the distance between the transmitting and receiving stations is large, exceeding the detection constant, the radar's coverage area becomes two separate regions, and its detection zone is no longer continuous. Current research on optimizing the deployment range of external radiation sources considers relatively few factors, mainly calculating the detection coverage area to guide deployment optimization, or simply analyzing the maximum detection range to consider the detection coverage. However, solely considering the detection coverage area is too simplistic. At maximum detection coverage, the external radiation source coverage is circular, and the receiving and transmitting stations overlap, failing to meet the requirement of separate transmitting and receiving for external radiation source detection, which necessitates a larger detection range. Conversely, solely considering the maximum detection range results in a smaller actual radar coverage area as the detection range increases. Therefore, a comprehensive consideration of both the detection area and the maximum detection range is necessary.

[0005] Since we want both a large detection coverage area and a large maximum detection distance, we need to normalize the detection coverage area and the maximum detection distance to obtain normalized detection coverage area and normalized maximum detection distance. Without normalization, we cannot comprehensively consider the weights of the maximum detection coverage area and the maximum detection distance, and thus cannot accurately determine the optimization model. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the prior art by providing an integrated active and passive radar detection and evaluation system. This system solves for the radar detection coverage area and maximum detection coverage distance in integrated active and passive scenarios, and performs normalization processing on each. Based on the results of the final evaluation and optimization model, it guides the optimized deployment of external radiation source radars.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides an integrated active and passive radar detection and evaluation system, comprising: S1. An active radar system and a separate external radiation source system are combined to form an integrated active and passive radar system. The detection coverage model of the integrated active and passive radar system is as follows: ; in The active radar detection coverage curve is a circle; The coverage curve for external coverage source radar detection is represented by the Cassini oval line.

[0008] S2. Calculate the detection coverage area of ​​the active and passive integrated radar system; S3. Calculate the maximum detection range of the active and passive integrated radar system; S4. Normalize the detection coverage area and maximum detection distance; S5. Construct an optimization model for the evaluation utility function based on comprehensive weighted factors.

[0009] Furthermore, S2 specifically refers to: Assuming the total detection coverage area of ​​the integrated active and passive radar system is... ,but Simplified expression: baseline length L and detection constant b The function, specifically: ; set up Baseline length L and detection constant b The ratio, then: ; when At that time, the curve of the external radiation source becomes a curve with a coverage area equal to the detection constant. For a circle with radius , find the intersection of the circle with radius . x The axis has two intersection points, which are set as follows from smallest to largest: and ,satisfy ; The area covered by the detection is: ; when When the external radiation source curve becomes approximately elliptical, calculate... The axis has two intersection points, which are set as follows from smallest to largest: and ,satisfy ; The area covered by the detection is: ; in, The external radiation source coverage area, determined by MATLAB computer simulation software, is located on the upper half of the x-axis. Expression when ) ; The intersection of the active radar coverage area and the external radiation source radar coverage area in the first quadrant. x Axis coordinates.

[0010] when At that time, the external radiation source curve is a Bernoulli bisporus, and... The axis has three intersection points, from smallest to largest: , , ,satisfy ; The area covered by the detection is: ; when At that time, the external radiation curve becomes two separate regions, and... The axis has four intersection points, namely: , , , ,satisfy ; The area covered by the detection is: .

[0011] Furthermore, S3 specifically refers to: when At that time, the maximum detection range is: ; when At that time, the external radiation source coverage and The intersection point of the axes is and For a given point, the maximum detection distance is: ; when When the maximum detection range is: ; when At that time, the area covered by the external radiation source is on one side of the region and The intersection points of the axes are as follows: and Point, the other side of the area and The intersection points of the axes are as follows: , Point, assumption , The maximum detection range is: .

[0012] Furthermore, when At that time, because the distance between the two-dimensional target detected by the radar and the transmitting station is The distance between the two-dimensional target detected by the radar and the receiving station is... The signal-to-noise ratio of the two-dimensional target detected by the radar is then... Must be greater than or equal to To achieve the detection of two-dimensional targets using radar, the following conditions must be met: ; in, This is the minimum detectable signal-to-noise ratio at the receiver output. but: ; when At that time, it is assumed that the two-dimensional target detected by the radar is located at On the axis, the distance between the two-dimensional target detected by the radar and the receiving station is... ( <1), the distance of the two-dimensional target detected by the radar from the transmitting station is Then the signal-to-noise ratio of the two-dimensional target detected by the radar must be greater than or equal to In order to achieve signal detection, then: .

[0013] Furthermore, S4 specifically includes: when At that time, the maximum detection range It has a maximum value Define the maximum detection coverage area after normalization. ,but: ; Computer simulation software can be used to calculate the total detection coverage area of ​​an integrated active and passive radar system. The maximum value is ,have Define the area of ​​the detection coverage after normalization. ;but: .

[0014] Furthermore, the evaluation utility function is defined as follows: : when At that time, due to the normalized detection coverage area and normalized maximum detection range If it changes continuously, then: ; in, They are respectively and The weighting factor, and satisfying ; when When external radiation sources deviate from their phase, a detection blind zone occurs. To reduce this blind zone, a penalty function needs to be constructed, and the utility function is then evaluated. express: ; To determine and Iterate through the values ​​afterward. The evaluation utility function is obtained after considering the range of values. Maximum value: ; When determined and Solve after value Maximum value obtained ; Besides taking the maximum value When will it be available? The optimal value is defined. The optimization range is: ; in, Selection factor; Define a normalized evaluation utility function for: ; when satisfy The optimization range is solved as follows: .

[0015] The beneficial effects of this invention are as follows: The radar system, which considers both an active radar system and an external radiation source radar system, can accurately calculate the detection coverage area of ​​the integrated active and passive radar system at different baseline distances; the maximum detection range of the radar system is expressed at different baseline distances, along with a normalized processing model for the maximum detection range, allowing for optimized deployment considering both detection coverage area and maximum detection range; the expression for the maximum detection range of the integrated active and passive radar system at different baseline distances, along with a normalized processing model for the maximum detection range, can be accurately calculated, and an evaluation optimization model based on weighted factors can be used to optimize the deployment between the transmitting and receiving stations, comprehensively considering both detection coverage area and maximum detection range.

[0016] This method considers different weighting factors for detection coverage area and maximum detection distance, proposes evaluation utility functions under different baseline distances, and solves for the maximum value of the evaluation utility function by ergonomic method when two weighting factors are determined. It also establishes an evaluation optimization method and obtains the preferred baseline distance location deployment under the active and passive integrated system through computer simulation. Compared with considering only the maximum detection distance or only the detection coverage area, this method has higher accuracy and reliability. Attached Figure Description

[0017] Figure 1 This is a basic geometric diagram of an external radiation source radar. Figure 2 A flowchart of an integrated active and passive radar detection and evaluation system; Figure 3 for When =2, the curve and Schematic diagram of the intersection of axes; Figure 4 for Time curve and Schematic diagram of the intersection of axes; Figure 5 for When =2, the curve and Schematic diagram of the intersection of axes; Figure 6 for Time curve and Schematic diagram of the intersection of axes; Figure 7 for Coverage map when the transmitting and receiving stations overlap; Figure 8 for Detection range diagram of integrated active and passive radar; Figure 9 for Detection range diagram of integrated active and passive radar; Figure 10 for Detection range diagram of integrated active and passive radar; Figure 11 To normalize the detection coverage area and The relationship between the curves; Figure 12 To normalize the maximum detection range and The relationship between the curves; Figure 13 For different When taking values, evaluate the utility function. and The relationship between the curves; Figure 14 For different When taking values, the normalized evaluation utility function and The relationship between the curves. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] External radiation source radar utilizes a third-party illumination source to detect targets. Selecting a suitable illumination source and receiving station can form a monitoring system. The geometric structure of an external radiation source radar, consisting of the illumination source, receiving station, and moving target, on a plane is as follows: Figure 1 As shown: in, and These represent the external radiation source and the receiving station of the external radiation source radar, respectively. The baseline length is the straight-line distance between the irradiation source and the receiving station. To detect the target's moving speed, For the target velocity direction and bistatic angle The angle between the bisectors, and These represent the distances from the external radiation source and the receiving station to the target, respectively. and These are the azimuth angles on the bistatic plane with the external radiation source and receiving station as the coordinate origins, respectively, also known as the target viewing angles on the bistatic plane. The bistatic angle is the angle between the target and the line connecting the external radiation source, the receiving station, and the target, with the target as the vertex.

[0020] By the Law of Cosines: ; (2.1) Let the distance from the external radiation source through the target to the receiving station be... Substituting into equation (2.1), we get: ; Where e is defined as the eccentricity of the equidistant ellipse, we get: ; Assume the maximum range product of the external radiation source radar is: ; in, The emission power of the irradiation source; This refers to the gain of the transmitting antenna; For receiving antenna gain; The wavelength of the external radiation source; The target scattering cross-section; , , where is the pattern propagation factor; g is the cumulative gain; Boltzmann's constant; The receiver noise temperature; The noise bandwidth before the receiver detector; The noise figure of the radar system; This is the minimum detectable signal-to-noise ratio at the receiver output. and These are the losses of the transmitting and receiving systems, respectively. To achieve the maximum detection range equivalent to a monostatic radar, a detection constant is defined. When the parameters are determined, The value is a fixed value.

[0021] Assuming that the transmitter of this external radiation source radar is also equipped with a receiving, signal processing, data processing, and display control terminal, the transmitter itself constitutes an active radar and can perform active radar detection. In this case, the radar detection coverage is determined by the detection constant. A circle with radius represents the scenario where the receiving station and the transmitting station overlap in an external radiation source.

[0022] Please see Figure 2 This system combines an active radar system and an external radiation source transceiver system into an integrated active and passive radar system.

[0023] Based on the aforementioned principle of external radiation source radar detection, it can be seen that, given a fixed set of external radiation source radar technical parameters, the detection range is primarily determined by the detection constant. Baseline length The detection constant is determined by factors such as the target angle. This is the maximum detection range equivalent to that of a monostatic radar.

[0024] When the baseline length is zero, the external radiation source radar degenerates into a monostatic radar, and its detection range is a radius equal to the detection constant. The detection range is a circle. As the baseline length increases, the detection range gradually changes from an ellipse to a dumbbell shape, then a double-button shape, until it splits into two discrete regions. The direction of the baseline is defined as the transverse direction, and the direction perpendicular to it is defined as the longitudinal direction. The coverage area of ​​the active detection is defined as the radius of the detection constant. The circle is assumed to be at point O, and the receiving station is at point A, with the baseline as... A rectangular coordinate system is established with the launch station as the origin.

[0025] Therefore, the total detection coverage area of ​​the active and passive integrated system is the total area enclosed by the Cassini oval line and the circle with radius b: ; Assuming the total detection coverage area of ​​the integrated active and passive radar system is... ,but Simplified expression: baseline length L and detection constant b The function, specifically: ; set up Baseline length L and detection constant b The ratio, then: ; when At that time, the curve of the external radiation source becomes a curve with a coverage area equal to the detection constant. A circle with radius , coinciding with the coverage of the active radar, such as Figure 3 As shown, find the relationship with x The axis has two intersection points, which are set as follows from smallest to largest: and ,satisfy ; The area covered by the detection is: ; when When the external radiation source curve becomes approximately elliptical, calculate... x The axis has two intersection points, which are set as follows from smallest to largest: and ,satisfy ,like Figure 4 As shown; Because the curve covered by the external radiation source is about x Axially symmetric figures, when hour, The values ​​of y correspond one-to-one, and can be fitted using Matlab computer simulation software. y about x Relationship curve The curve that corresponds to the coverage of the active radar is a circle. After they intersect, there is an intersection point. Figure 4 The example shown assumes that the intersection points in the first quadrant obtained by solving are... And there are .

[0026] The area covered by the detection is: ; like Figure 5 As shown, when At that time, the external radiation source curve is a Bernoulli bisporus, and... x The axis has three intersection points, from smallest to largest: , , ,satisfy The area of ​​the external radiation source can be obtained from the area of ​​the hyoid line. However, half of them are within the active coverage area.

[0027] The area covered by the detection is: ; like Figure 6 As shown, when At this point, the outer radiation curve becomes two separate regions, each approximating an ellipse, and the curve intersects with... The axis has four intersection points, namely: , , , ,satisfy ; External radiation pattern about Axis and baseline midpoint It is symmetrical, but half of the coverage is still within the active coverage detection range. Therefore, the area of ​​the detection coverage range is: .

[0028] In summary, the total detection coverage area of ​​the integrated active and passive radar system is: for: ; Analysis of maximum lateral detection range With baseline length Detection constant The relationship.

[0029] like Figure 7 As shown, when At that time, the maximum detection range is: ; like Figure 8 As shown, when When, that is, when the baseline length When the detection constant is m times, assume the external radiation source coverage is equal to... The intersection point of the axes is and Points, known by symmetry Assuming Maximum detection range in elliptical or dumbbell-shaped coverage areas Represented as: ; like Figure 9 As shown, when When the maximum detection range is: ; like Figure 10 As shown, when At that time, the baseline length is At that time, the detection range split into two irregular shapes. The larger the area, the smaller the irregular region; the coverage area of ​​the external radiation source is on one side of the region. The intersection points of the axes are as follows: and Point, the other side of the area and The intersection points of the axes are as follows: , Point, assumption , The maximum detection range is defined as the active coverage radius plus the external radiation coverage area on the other side. ,Right now Remove the parts that are separated in the middle and not within the coverage area.

[0030] Then when the baseline length is the detection constant Double time ( The irregular region is divided into two parts, one of which is located within the circular coverage area, represented as: ; In summary, the maximum detection range Represented as: ; when At that time, because the distance between the two-dimensional target detected by the radar and the transmitting station is The distance between the two-dimensional target detected by the radar and the receiving station is... The signal-to-noise ratio of the two-dimensional target detected by the radar is then... for: ; The transformation yields: ; The signal-to-noise ratio of the two-dimensional target detected by the radar is then... Must be greater than or equal to To achieve two-dimensional target detection using radar, we have: ; Right now: ; Find: ; ; ; but: ; when At that time, assuming the target is located On the axis, the distance between the two-dimensional target detected by the radar and the receiving station is... ( <1), the distance of the two-dimensional target detected by the radar from the transmitting station is Then the signal-to-noise ratio of the two-dimensional target detected by the radar is: ; Must be greater than or equal to Only then can signal detection be achieved. When calculating the maximum detection range, we have: ; ; ; have to: .

[0031] Therefore, the maximum detection range of the active and passive integrated radar system Represented as: .

[0032] when At that time, the maximum detection range It has a maximum value Define the maximum detection coverage area after normalization. ,but: ; Computer simulation software (such as Matlab) can be used to calculate the total detection coverage area of ​​an integrated active and passive radar system. The maximum value is ,have Define the area of ​​the detection coverage after normalization. ;but: .

[0033] When the parameters are determined, the detection constant The value is a fixed value, therefore the normalized detection coverage area is calculated after normalization. and normalized maximum detection range It is with Change with change.

[0034] Define the evaluation utility function as follows , because When the values ​​are large, both the area of ​​the external radiation source and the maximum detection coverage distance are small. The total detection coverage area of ​​the integrated active and passive radar is approximately equal to the area of ​​the active radar. Therefore, we can consider only the area of ​​the active radar. The range of values, where It is a fixed value greater than 2, and can be taken as 10 during simulation.

[0035] when At that time, due to the normalized detection coverage area and normalized maximum detection range If it is continuously changing, then evaluate the utility function. It is expressed as follows: ; in, They are respectively and The weighting factor, and satisfying Adjustments can be made based on the actual situation.

[0036] when If the external radiation source is out of phase, a detection blind zone will occur. Therefore, a penalty function needs to be constructed: ; The utility function is obtained by synthesis. for: ; When the primary consideration is the detection coverage area, it can be appropriately increased. When the maximum detection range is the primary consideration, the value needs to be appropriately increased. Value. When determined and After obtaining the value, the evaluation utility function can be calculated. The range of values, To determine and Iterate through the values ​​afterward. The evaluation utility function is obtained after considering the range of values. Maximum value: ; When determined and Solve after value Maximum value obtained ; Besides taking the maximum value When will it be available? The optimal value is defined. The optimization range is: ; in, Selection factor; a value of 0.98 is generally acceptable. This means the range satisfies the maximum value of the evaluation utility function. Within range The range of values ​​is the selected comparison optimization. Value, at this time the corresponding Value multiplied by the probe constant This refers to the baseline distance between the receiving station and the illumination source, as optimized by the algorithm. The value of .

[0037] Define a normalized evaluation utility function for: ; when satisfy The optimization range is solved as follows: .

[0038] Through comparison and It can quickly determine the preferred option. The range of values ​​that can be taken, and the corresponding value at this time. Value multiplied by the probe constant This refers to the baseline distance between the receiving station and the illumination source, as optimized by the algorithm. The value of .

[0039] Simulation analysis: Simulation parameter settings The active and passive integrated detection range was analyzed under the condition of FM as the irradiation source. The simulation parameters are shown in the table.

[0040] Table 1. Parameters of external radiation source radar with FM frequency modulation signal as illumination source

[0041] Substituting the parameters in Table 1 into the formula for external radiation source radar, the detection constant b can be obtained.

[0042] Please see Figure 11 ,when When only the impact of the detection coverage area is considered, the utility function is simplified to a curve that only considers the normalized detection coverage area. As can be seen in the figure, when the baseline distance (distance between the transmitting station and the receiving station) is considered... =1.65b ( When the value is 1.65, the normalized maximum detection coverage area is 1. Areas within 98% of the maximum detection range are considered to have good detection coverage. The value range is 1.4b to 1.9b.

[0043] Please see Figure 12 ,when When considering only the impact of the maximum detection range, the utility function is simplified to consider only the normalized maximum detection coverage range. As shown in the figure, when the baseline distance (distance between the transmitting and receiving stations) is considered... =2b( When =2), the normalized maximum detection range value is 1. If the maximum detection range is within 98%, it is considered a region with good detection range. The value range is 1.9b to 2b.

[0044] different When taking values, evaluate the utility function. and normalized evaluation utility function and The curves between them are shown in the following figures.

[0045] Please see Figure 13 and Figure 14 ,when At that time, the main consideration is the impact of the maximum detection coverage area. At that time, when the baseline distance (distance between the transmitting station and the receiving station) is... =1.75b ( When the value is 1.75, the maximum value is 1. According to the maximum normalized evaluation utility function, within 98% of the range, the evaluation utility function is considered high. Therefore, it is recommended to... The value range is 1.4b to 1.9b. At that time, when the baseline distance (distance between the transmitting station and the receiving station) is... =1.85b ( When the value is 1.85, the maximum value is 1. According to the maximum normalized evaluation utility function, within 98% of the range, the evaluation utility function is considered high. In this case, a baseline distance is recommended. The value range is 1.6b to 2b. Therefore, when primarily considering the impact of the maximum detection coverage area, it is recommended that the baseline distance deployment L range from 1.6b to 1.9b.

[0046] when At that time, the main consideration is the impact of the maximum detection range. When the baseline distance (distance between the transmitting station and the receiving station) is... =2b( When the value is 2), the maximum value is 1. According to the maximum normalized evaluation utility function, within 98% of the range, the evaluation utility function is considered high. Therefore, it is recommended to... The value range is 1.9b to 2b; At that time, when the baseline distance (distance between the transmitting station and the receiving station) is... =2b( When the value is 2), the maximum value is 1. According to the maximum normalized evaluation utility function, within 98% of the range, the evaluation utility function is considered high. Therefore, it is recommended to... The value range is 1.9b to 2b. Therefore, when primarily considering the impact of the maximum detection coverage area, it is recommended that the baseline distance deployment L range from 1.9b to 2b.

[0047] when When considering that the maximum detection range and the maximum coverage area are weighted equally, the baseline distance (distance between the transmitting station and the receiving station) is taken into account. =1.95b ( When the value is 1.95, the maximum value is 1. According to the maximum normalized evaluation utility function, within 98% of the range, the evaluation utility function is considered high, and in this case, it is recommended... The value range is 1.75b to 2b.

[0048] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be defined by the appended claims.

Claims

1. An integrated active and passive radar detection and evaluation system, characterized in that, include: S1. An active radar system and a separate external radiation source system are combined to form an integrated active and passive radar system. The detection coverage model of the integrated active and passive radar system is as follows: ； S2. Calculate the detection coverage area of ​​the active and passive integrated radar system; S3. Calculate the maximum detection range of the active and passive integrated radar system; S4. Normalize the detection coverage area and maximum detection distance; S5. Construct an optimization model for the evaluation utility function based on comprehensive weighted factors.

2. The active and passive integrated radar detection and evaluation system according to claim 1, characterized in that, Specifically, S2 is: Assuming the total detection coverage area of ​​the integrated active and passive radar system is... ,but Simplified expression: baseline length L and detection constant b The function, specifically: ； set up Baseline length L and detection constant b The ratio, then: ； when At that time, the curve of the external radiation source becomes a coverage area with a detection constant. For a circle with radius , find the intersection of the circle with radius . x The axis has two intersection points, which are set as follows from smallest to largest: and ,satisfy ; The area covered by the detection is: ； when When the external radiation source curve becomes approximately elliptical, calculate... x The axis has two intersection points, which are set as follows from smallest to largest: and ,satisfy ; The area covered by the detection is: ； when At that time, the external radiation source curve is a Bernoulli bisporus, and... x The axis has three intersection points, from smallest to largest: , , ,satisfy ; The area covered by the detection is: ； when At that time, the external radiation curve becomes two separate regions, and... x The axis has four intersection points, namely: , , , ,satisfy ; The area covered by the detection is: 。 3. The active and passive integrated radar detection and evaluation system according to claim 2, characterized in that, Specifically, S3 is: when At that time, the maximum detection range is: ; when At that time, the external radiation source coverage and The intersection point of the axes is and For a given point, the maximum detection distance is: ； when When the maximum detection range is: ; when At that time, the area covered by the external radiation source is on one side of the region and The intersection points of the axes are as follows: and Point, the other side of the area and The intersection points of the axes are as follows: , Point, assumption , The maximum detection range is: 。 4. The active and passive integrated radar detection and evaluation system according to claim 3, characterized in that: when At that time, it is assumed that the two-dimensional target detected by the radar is located at x On the axis, the distance between the two-dimensional target detected by the radar and the transmitting station is... The distance between the two-dimensional target detected by the radar and the receiving station is... The signal-to-noise ratio of the two-dimensional target detected by the radar is... Must be greater than or equal to To achieve the detection of two-dimensional targets using radar, the following conditions must be met: ； in, This is the minimum detectable signal-to-noise ratio at the receiver output. but: ； when At that time, it is assumed that the two-dimensional target detected by the radar is located at x On the axis, the distance between the two-dimensional target detected by the radar and the receiving station is... ( <1), the distance of the two-dimensional target detected by the radar from the transmitting station is Then the signal-to-noise ratio of the two-dimensional target detected by the radar must be greater than or equal to In order to achieve signal detection, then: 。 5. The active and passive integrated radar detection and evaluation system according to claim 4, characterized in that, Specifically, S4 is: when At that time, the maximum detection range It has a maximum value Define the maximum detection coverage area after normalization. ,but: ； Computer simulation software can be used to calculate the total detection coverage area of ​​an integrated active and passive radar system. The maximum value is ,have Define the area of ​​the detection coverage after normalization. ;but: 。 6. The active and passive integrated radar detection and evaluation system according to claim 5, characterized in that, Define the evaluation utility function as follows : when At that time, due to the normalized detection coverage area and normalized maximum detection range If it changes continuously, then: ； in, They are respectively and The weighting factor, and satisfying ; when When external radiation sources deviate from their phase, a detection blind zone occurs. To reduce this blind zone, it is necessary to construct an evaluation penalty function, which in turn evaluates the utility function. express: ； To determine and Iterate through the values ​​afterward. After taking the range of values, we get Maximum value: ； When determined and Solve after value Maximum value obtained ; Besides taking the maximum value When will it be available? The optimal value is defined. The optimization range is: ； in, Selection factor; Define a normalized evaluation utility function for: ； when satisfy The optimization range is solved as follows: 。

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