Electromagnetic sensitivity judgment method based on critical state trace point echo display

Abstract

The invention discloses an electromagnetic sensitivity determination method based on critical state trace point echo display, and the method comprises the steps: firstly, setting signal processing, enabling trace point condensation to meet a false alarm rate index, and detecting the critical state observation trace point and echo change of a target under the condition of no emission; then eliminating sensitivity caused by non-effective interference signals of the test equipment through radar receiving channel sensitivity criteria, eliminating interference signals in a radio frequency bandwidth range, eliminating interference signals generated by the test equipment in a radar radio frequency range, and eliminating interference signals generated when interference signal harmonic waves enter the radar radio frequency range; and interference signals generated by noise of the power amplifier are eliminated. According to the method, various sensitive phenomena can be comprehensively displayed, reasonable sensitive phenomena are eliminated, and a comprehensive and accurate radar receiving channel electromagnetic sensitivity test sensitive judgment result is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of radar electromagnetic sensitivity testing, and in particular relates to an electromagnetic sensitivity determination method based on critical state point trace echo display. Background Art

[0002] Since the radar receiving channel is very sensitive to electromagnetic signals, radar equipment often encounters problems such as insufficient measurement during the measurement of electromagnetic signal sensitivity, which causes some sensitive problems to not be exposed, and the inability to exclude reasonable sensitive situations, which causes some normal phenomena to be judged as sensitive problems.

[0003] If a lot of signal processing, data processing and display control are applied during the electromagnetic sensitivity measurement of the radar receiving channel, such as anti-interference suppression, high detection threshold, high moving target processing threshold and other signal processing settings; the screen display does not show dots, the echo display threshold is relatively high and other display processing settings. This will cover up the weaker sensitivity phenomenon. Such a test cannot effectively reflect the sensitivity of the radar receiving channel to the external electromagnetic environment, resulting in inadequate electromagnetic sensitivity test.

[0004] If the following reasonable interference signals cannot be eliminated, misjudgment of the electromagnetic sensitivity of the radar receiving channel will occur: for example, external interference signals are reflected by mirrors into the receiver, which are interference signals within the radar RF range; interference signals within the radar RF frequency range generated by the test equipment itself; the frequencies of multiple harmonics of effective interference signals enter the radar RF operating bandwidth; the noise generated by power amplifiers with overlapping frequencies is increased, and the noise frequency enters the radar operating frequency band. Summary of the invention

[0005] The present invention aims to solve the problems raised in the background technology and proposes an electromagnetic sensitivity determination method based on critical state point trace echo display.

[0006] In order to achieve the purpose of the present invention, the present invention discloses an electromagnetic sensitivity determination method based on critical state point trace echo display, comprising the following steps:

[0007] Step 1: Deploy the test scenario;

[0008] Step 2: Observe the changes in the critical state traces and echo display, determine the electromagnetic sensitivity, and comprehensively measure the phenomenon of the radar's sensitive response to interference signals;

[0009] Step 3: Based on the observed radar trace sensitivity or echo sensitivity, reasonable sensitive phenomena are eliminated, and the remaining sensitive phenomena are real sensitive phenomena.

[0010] Furthermore, step 1 specifically includes the following steps:

[0011] Step 1-1, select a shielded darkroom as the test environment, and avoid storing irrelevant metal objects in the darkroom;

[0012] Step 1-2: Connect the designated test equipment to the darkroom via cables for operation;

[0013] Steps 1-3: Turn on the radar under test, power on the receiving channel, turn off the transmitting channel, and adjust the signal processing function and related parameters.

[0014] Furthermore, in step 2, by adjusting the signal processing, data processing functions and related parameters, it is achieved that point traces can be extracted from the noise in the non-transmitting state, and the false alarm rate meets the radar false alarm index requirements; the echo display processing is adjusted to be able to display the echoes corresponding to all point traces; the changes in point traces and echoes are observed. If the number of point traces on a certain azimuth line or in a certain sector area is at least twice as much as before, and the corresponding echo amplitude multiple increases, it is preliminarily determined to be a sensitive state.

[0015] Furthermore, in step 3, reasonable sensitive phenomena include sensitivity caused by non-effective interference signals of the test equipment, sensitivity caused by interference signals within the RF bandwidth of the tested radar, sensitivity caused by interference signals within the radar RF frequency range generated by the test equipment itself, sensitivity caused by interference signals generated by harmonics of interference signals entering the radar RF range, sensitivity caused by interference signals generated by the power amplifier's own noise, and sensitivity caused by interference signals that can be removed by anti-interference measures taken on the basis of ensuring the functional performance of the radar.

[0016] Furthermore, the specific steps to eliminate the sensitivity caused by the non-effective interference signal of the test equipment are as follows: reproduce the test scene, including the layout of surrounding objects, the status of the test equipment, and personnel changes; if the sensitive phenomenon reappears, adjust the object that can reflect the signal into the radar receiving channel, and observe the sensitivity changes; find the reflector signal source, and once it is found that adjusting a certain reflective object can cause sensitive changes, further use the same method to find the reflector signal source; repeat the above operations, gradually eliminate the influence of other factors, and finally find the non-effective interference signal of the test equipment.

[0017] Furthermore, the specific steps to eliminate the sensitivity caused by interference signals within the RF bandwidth of the tested radar are as follows: determine whether the frequency of the interference signal belongs to the protection range of the radar RF range; if it belongs to the frequency range with a bandwidth extended by 2 times above and below the radar carrier frequency range, it is an interference signal within the RF bandwidth of the tested radar.

[0018] Furthermore, the specific steps to eliminate the sensitivity caused by the interference signal within the radar RF frequency range generated by the test equipment itself are as follows: reproduce the test scene, including the layout of surrounding objects, the status of the test equipment, and personnel changes; if the phenomenon reappears, adjust the status of the test equipment that can transmit signals into the radar receiving channel, and observe the changes in sensitivity; if the sensitivity phenomenon is weakened by more than half or disappears when the test equipment is turned off, it is judged to be related to the test equipment; if the test equipment is not a necessary equipment that needs to inject interference signals into the radar, it should be considered to remove the equipment and re-test or determine that the sensitivity is invalid.

[0019] Furthermore, the specific steps for eliminating the sensitivity caused by the interference signal generated by the interference signal harmonics entering the radar radio frequency range are as follows: calculate whether the integer multiples of the interference signal frequency belong to the frequency bandwidth range of the radar's current operation, and if so, preliminarily determine that it is a certain multiple harmonics of the interference signal; further test the harmonic signal through the receiving antenna and spectrum analyzer equipment, adjust the spectrum analyzer test frequency band range to include the current radio frequency bandwidth range of the radar, and measure the intensity of the multiple harmonic signals generated by the interference signal and the ratio of the environmental noise; if the amplitude is more than twice the noise amplitude of the surrounding environment, it is determined that the sensitivity is generated by the multiple harmonics of the interference signal entering the radar working frequency band.

[0020] Furthermore, the specific steps to eliminate the sensitivity caused by the interference signal generated by the noise of the power amplifier itself are as follows: after the interference signal power amplifier and the transmitting antenna are turned on, no matter which frequency the power amplifier works at, obvious interference enhancement can be seen on the radar screen; through the receiving antenna and spectrum analyzer equipment test, the receiving frequency range is adjusted on the spectrum analyzer to include the current RF bandwidth range of the radar, and the strength of the interference signal is measured and compared with the ambient noise after turning off the power amplifier; if the amplitude is more than twice the noise amplitude of the surrounding environment, it can be determined that the interference noise generated by the power amplifier itself that generates the interference signal enters the radar working frequency band and causes sensitivity.

[0021] Furthermore, the specific steps for eliminating the sensitivity caused by interference signals that can be removed by anti-interference measures taken on the basis of ensuring the functional performance of the radar are as follows: during the test of the power and accuracy indicators of the radar equipment, the signal processing settings are statistically analyzed to obtain the specific setting parameters of the anti-interference measures that do not affect the functional performance of the radar; when encountering sensitive situations, the specific setting parameters of the anti-interference measures that do not affect the functional performance of the radar are adopted, and the interference signals that can be eliminated by the radar's own anti-interference measures are reasonable electromagnetic sensitivities, and such interference signals are eliminated.

[0022] Compared with the prior art, the significant progress of the present invention lies in: determining electromagnetic sensitivity based on critical state point traces and echo display changes, and eliminating reasonable sensitive phenomena; compared with the prior art, it can more comprehensively expose the sensitivity of the radar receiving channel to electromagnetic waves, and can eliminate reasonable sensitive phenomena, thereby achieving sufficient testing and reasonable determination of the electromagnetic sensitivity of the radar receiving channel, and improving the quality of the radar's anti-electromagnetic sensitivity capability.

[0023] In order to more clearly illustrate the functional characteristics and structural parameters of the present invention, further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 It is a schematic diagram of a critical state display screen;

[0026] Figure 2 It is a schematic diagram of the weak sensitivity phenomenon;

[0027] Figure 3 It is a schematic diagram of the strong sensitivity phenomenon;

[0028] Figure 4 It is a schematic diagram of the mirror reflection of the interference signal. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] A method for determining electromagnetic sensitivity based on critical state dot trace echo display, the specific implementation method is as follows: electromagnetic sensitivity measurement must first comprehensively measure the sensitive response phenomenon to interference signals, then eliminate reasonable sensitive reasons, and accurately locate the real sensitive situation.

[0031] Since the radar receiving channel is very sensitive to electromagnetic waves, if you want to see a more comprehensive actual situation, you need to fully display the receiver's response to environmental changes, and then determine whether the device is sensitive to interference signals based on the sensitivity and the cause of the sensitivity.

[0032] In order to obtain comprehensive sensitive signals, the radar needs to be adjusted to the most sensitive state. By adjusting the signal processing function, data processing (such as detection threshold), dot trace display and other related parameters, the dot trace can be extracted and displayed from the noise in the non-transmitting state, and the false alarm rate (generally required not to exceed 10 -6 ) meets the index requirements; the sensitive phenomenon of the radar receiving channel can be fully and vividly demonstrated through obvious changes in point traces and echoes.

[0033] By adjusting the radar's echo display threshold, echo display control, etc., the echoes corresponding to all the points are displayed, and the sensitive phenomena are fully and vividly expressed through obvious changes in the echo display.

[0034] Radar sensitivity criterion mainly solves the problem of excluding reasonable sensitivity phenomena based on the observed radar trace sensitivity or echo sensitivity. The sensitivity that the radar itself should be able to avoid but has not been avoided is determined as the sensitivity criterion. The specific contents are as follows:

[0035] 1) There are unavoidable interference signals within the radar RF frequency range in the radar test environment. Although the interference signal will not directly enter the radar receiver, if there are objects such as metal that strongly reflect electromagnetic waves around, the signal can enter the radar receiving channel through multiple mirror reflections. The specific number of reflections is related to the strength of the signal and the sensitivity of the radar receiver.

[0036] 2) The radar carrier frequency range belongs to the normal working range. The sensitivity caused by the interference signal entering this frequency range is normal. The radar receiving filters at all levels have a certain redundancy range. The RF level filter mainly filters the farther harmonic signals. The digital level filter is relatively sensitive. Its filtering range is mainly related to the RF bandwidth. The interference signal that exceeds the 2 times bandwidth range should be processed by the radar. In other words, there are still interference signals outside this range that should be considered as the radar's sensitive criterion. For example, the radar's operating RF frequency range is 7800MHz to 8800MHz and its operating bandwidth is 35MHz. It is more reasonable to define its protected radar carrier frequency range as 7730MHz to 8870MHz.

[0037] 3) Multiple harmonics of instruments and meters used to test the sensitivity of radar equipment generate interference signals that enter the receiver. For example, the noise interference signal generated by the cable bundle injected into the direction of the power amplifier and the display screen of the oscilloscope in the conducted sensitivity measurement equipment leaks, causing radar sensitivity. The leakage is mainly concentrated in the high frequencies of 100MHz and 30MHz. When working in this frequency band, an interference signal of 8GHz to 10GHz will be generated, which is stronger than the noise. Therefore, the criterion for the radar's sensitivity to interference signals excludes interference signals within the radar RF frequency range generated by the test equipment itself. The cable bundle injected into the conducted sensitivity measurement equipment will emit interference signals within the radar RF range into the air in a certain direction of its screen and power amplifier.

[0038] 4) During the measurement of electric field radiation sensitivity, the second harmonic, third harmonic, eighth harmonic, and ninth harmonic of the interference signal will generate interference signals that are significantly higher than the noise. Therefore, the criterion for radar sensitivity to interference signals excludes noise interference signals within the radar RF frequency range that are entered by multiple harmonics of the test interference signal.

[0039] 5) During the electric field radiation sensitivity measurement process, if the frequency range of the power amplifier that generates the interference signal overlaps with the actual RF range of the radar, the noise generated by the power amplifier that generates the interference signal will be raised in the entire frequency range, and an obvious interference signal will be generated on the radar under test. For example, in the RS103 test, the frequency range of the power amplifier is 6GHz-18GHz, and its corresponding transmitting antenna also meets the condition requirements. If the RF range of the radar under test is 7800MHz to 8800MHz, then interference signals from 6GHz to 18GHz will appear at all working frequency points within the entire working range of the power amplifier, and the interference signal is significantly higher than the environmental noise. Therefore, the criterion for the radar's sensitivity to interference signals excludes interference signals within the radar RF frequency range generated by the test equipment itself. The overall noise in the frequency range generated by the power amplifier is increased, and this noise range covers the RF band where the radar RF is located.

[0040] 6) For electromagnetic sensitivity phenomena that do not belong to the above reasonable ones, the sensitive phenomenon can be eliminated by taking anti-interference measures such as constant false alarm and moving target processing, and the application of such measures does not reduce the functional performance indicators of the radar. This measure is part of the radar's anti-electromagnetic sensitivity capability, so if the sensitive phenomenon can be eliminated by taking anti-interference measures such as constant false alarm and moving target processing, and the application of such measures does not reduce the functional performance indicators of the radar, the tested radar should not be judged as sensitive.

[0041] Specifically, the dot traces are condensed and the echo display is in a critical state. Observe the changes of dot traces and echoes; exclude the changes of dot traces and echoes caused by reasonable reasons. If there are obvious changes, it is judged as sensitive. Figure 1As shown, the signal processing, point trace extraction processing and echo display processing are adjusted to meet the false alarm rate and a critical state where the false alarm point trace and the corresponding echo can be seen.

[0042] Specifically, by adjusting the signal processing, data processing functions and related parameters, it is achieved that point traces can be extracted from the noise in the non-transmitting state, and the false alarm rate meets the radar false alarm index requirements; the echo display processing is adjusted to be able to display the echoes corresponding to all point traces; the changes in point traces and echoes are observed, and if there are obvious changes, it is preliminarily determined to be a sensitive state.

[0043] Specifically, exclude the changes in traces and echoes caused by reasonable reasons. If there are obvious changes, it is judged as sensitive. Reasonable reasons include: the radar receiving channel sensitivity criterion excludes the sensitivity caused by non-effective interference signals of the test equipment, excludes interference signals within the RF bandwidth of the tested radar, excludes interference signals within the radar RF frequency range generated by the test equipment itself, excludes interference signals generated by harmonics of interference signals entering the radar RF range, excludes interference signals generated by the noise of the power amplifier itself, and excludes interference signals that can be removed by anti-interference measures taken on the basis of ensuring the functional performance of the radar.

[0044] Specifically, the radar receiving channel sensitivity criterion excludes the sensitivity caused by the ineffective interference signal of the test equipment. The higher the radar carrier frequency, the more obvious its mirror emission is, excluding the sensitivity caused by the interference signal in the radio frequency range that is reflected by the mirror into the radar receiving channel. Figure 4 As shown in the figure, the dotted line is the path of the interference signal, and the dotted arrow is the mirror reflection direction of the interference signal.

[0045] Specifically, the radar receiving channel sensitivity criterion excludes interference signals within the radar RF frequency range. It is normal for the radar to be sensitive to signals within the carrier frequency range. According to actual conditions, this range should be a frequency range that extends no less than 2 times the bandwidth above and below the carrier frequency range.

[0046] Specifically, the radar receiving channel sensitivity criterion excludes interference signals within the radar RF frequency range generated by the test equipment itself. For example, the cable bundle is injected into the conducted sensitivity measurement equipment, and its screen or power amplifier may emit interference signals within the radar RF range into the air in a certain direction.

[0047] Specifically, the radar receiving channel sensitivity criterion excludes interference signals generated by interference signal harmonics entering the radar radio frequency range. The radar has a high sensitivity and can respond to the 2nd, 3rd, and even 9th harmonics of the test equipment, forming sensitivity.

[0048] Specifically, the radar receiving channel sensitivity criterion excludes the interference signal generated by the power amplifier itself that produces effective interference signals entering the radar RF bandwidth range. The overall noise in the frequency range generated by the power amplifier is increased. If this noise frequency range overlaps with the RF band where the radar RF is located, corresponding sensitivity will be generated.

[0049] Specifically, the radar receiving channel sensitivity criterion excludes interference signals that can be removed by anti-interference measures to ensure the functional performance of the radar. When encountering sensitive situations, the radar's own anti-interference measures are taken without affecting the function and performance of the radar. Interference signals that can be effectively eliminated belong to reasonable electromagnetic sensitivity.

[0050] Example

[0051] 1) First, choose a shielded darkroom as the ideal test environment. Try to avoid storing metal objects that are not related to the test equipment in the darkroom. Especially metal objects that are equal to or higher than the test object. If there are similar metal objects around that will produce strong reflections of electromagnetic waves, the signal can enter the radar receiving channel through multiple mirror reflections. The specific number of reflections is related to the strength of the signal and the sensitivity of the radar receiver.

[0052] 2) Sensitivity measurement should be carried out in a single project as far as possible, and multiple projects should not be tested in the same darkroom simultaneously, so as to avoid mutual interference between synchronous tests of the projects. For example, when conducting sensitivity measurement, if the cable bundle injection conduction sensitivity measurement is carried out in the same electromagnetic space, the noise interference signal generated in the direction of the power amplifier and the oscilloscope display screen in the cable bundle injection conduction sensitivity measurement equipment will leak, causing radar sensitivity. The leakage is mainly concentrated in the high frequencies of 100MHz and 30MHz. When working in this frequency band, an interference signal of 8GHz to 10GHz will be generated, which is stronger than the noise of the radar receiver. Therefore, the criterion for the radar's sensitivity to interference signals excludes the interference signals within the radar RF frequency range generated by the test equipment itself. The cable bundle injection conduction sensitivity measurement equipment will emit interference signals within the radar RF range into the air in a certain direction from its screen and power amplifier.

[0053] 3) During the sensitivity measurement, try to connect the test equipment to the outside of the darkroom through cables. The relevant test equipment includes: equipment other than the probe in the field strength detector, power amplifier equipment, signal source, oscilloscope, spectrum analyzer, display, etc.

[0054] 4) Turn on the radar under test, power on the receiving channel, close the transmitting channel, adjust the signal processing function and related parameters to extract the point trace of the noise in the non-transmitting state, and the false alarm rate (generally required not to exceed 10 -6 ) to meet the index requirements; adjust the echo display processing related parameters to be able to display the echo corresponding to the false alarm trace in the non-transmitting state. The display screen is as follows Figure 1As shown. By adjusting the radar to the most sensitive state through this step, you can obtain comprehensive sensitive signals. The radar receiving channel sensitivity phenomenon can be fully demonstrated through the obvious changes in the traces and echoes. Figure 2 As shown in the figure, the number of sensitive sector dots increases significantly, but it has not reached saturation. The echo intensity is significantly enhanced. If there is an echo amplitude display, it can be seen that the echo amplitude increases by more than 2 times. When severe sensitivity occurs, the screen is as follows Figure 3 As shown, the trace is saturated, and only some strong echoes in the detection sector can output traces. If the echo can be displayed, it can be seen that the overall intensity of the echo is much greater than 2 times the original or has been saturated.

[0055] 5) Start the test and observe the changes in the traces and echoes. If obvious changes occur, compare the following steps to eliminate reasonable sensitive situations.

[0056] 6) Reproduce the test scenario, including the layout of surrounding objects, the status of test equipment, personnel changes, etc. If the phenomenon reappears, adjust the object that can reflect the signal into the radar receiving channel and observe the sensitivity changes; if found, further use the same method to find the signal source of the reflector; repeat this operation to find the interference source. Figure 4 Schematic diagram of the mirror reflection process of the interference signal verified by experiment.

[0057] 7) Determine whether the frequency of the interference signal belongs to the protection range of the radar radio frequency range; that is, whether it belongs to the frequency range of the carrier frequency range with a bandwidth of 2 times above and below. For example, if the radar works in the radio frequency range of 7800MHz to 8800MHz and its working bandwidth is 35MHz, then its protected radar carrier frequency range should be defined as 7730MHz to 8870MHz.

[0058] 8) Reproduce the test scenario, including the layout of surrounding objects, the status of test equipment, personnel changes, etc. If the phenomenon reappears, adjust the status of the test equipment that can transmit signals into the radar receiving channel and observe the changes in sensitivity; if the sensitive phenomenon is significantly weakened or disappears when the test equipment is turned off, it can be judged that it is related to the test equipment. If the test equipment is not a necessary equipment such as an antenna that needs to inject interference signals into the radar, it should be considered to remove the equipment and re-test or determine that the sensitivity is invalid.

[0059] 9) Calculate whether the integer multiples of the interference signal frequency belong to the frequency bandwidth range of the radar's current operation. If so, it basically proves that some multiple harmonics of the interference signal are generated. The harmonic signal can be further tested by receiving antennas, spectrum analyzers and other equipment. Adjust the spectrum analyzer test frequency band range to include the radar's current RF bandwidth range, measure the intensity of the multiple harmonic signals generated by the interference signal and compare it with the environmental noise. If it is significantly higher than the noise of the surrounding environment, it can be determined that the multiple harmonics of the interference signal enter the radar's operating frequency band and are sensitive.

[0060] 10) After the interference signal amplifier and transmitting antenna are turned on, no matter which frequency the amplifier is working at, the radar screen can see obvious interference enhancement. It can be tested through receiving antenna, spectrum analyzer and other equipment. Adjust the receiving frequency range on the spectrum analyzer to include the current RF bandwidth of the radar, measure the intensity of the interference signal and compare it with the environmental noise after turning off the amplifier. If it is significantly higher than the noise of the surrounding environment, it can be determined that the interference noise generated by the amplifier itself generated by the interference signal enters the radar working frequency band and is sensitive.

[0061] 11) During the test of the power, accuracy and other main indicators of the radar equipment, the signal processing settings are statistically analyzed to obtain the specific setting parameters of the anti-interference measures that do not affect the functional performance of the radar. For electromagnetic sensitivity phenomena that do not belong to the above reasonable electromagnetic sensitivity phenomena, the parameter settings that do not affect the functional performance obtained by the statistical results are used to achieve the effect of anti-interference measures to eliminate the sensitive phenomenon.

[0062] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0063] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for determining electromagnetic sensitivity based on critical state dot trace echo display, characterized in that: The following steps are involved: Step 1: Deploy the test scenario; Step 2: Observe the changes in the critical state traces and echo display, determine the electromagnetic sensitivity, and comprehensively measure the phenomenon of the radar's sensitive response to interference signals; Step 3: Based on the observed radar trace sensitivity or echo sensitivity, reasonable sensitive phenomena are excluded, and the remaining sensitive phenomena are real sensitive phenomena.

2. The electromagnetic sensitivity determination method based on critical state dot trace echo display according to claim 1, characterized in that: Step 1 specifically includes the following steps: Step 1-1, select a shielded darkroom as the test environment, and avoid storing irrelevant metal objects in the darkroom; Step 1-2: Connect the designated test equipment to the darkroom via cables for operation; Steps 1-3: Turn on the radar under test, power on the receiving channel, turn off the transmitting channel, and adjust the signal processing function and related parameters.

3. The electromagnetic sensitivity determination method based on critical state dot trace echo display according to claim 1, characterized in that: In step 2, by adjusting the signal processing, data processing functions and related parameters, it is achieved that point traces can be extracted from the noise in the non-transmitting state, and the false alarm rate meets the radar false alarm index requirements; the echo display processing is adjusted to be able to display the echoes corresponding to all point traces; the changes in point traces and echoes are observed. If the number of point traces on a certain azimuth line or in a certain sector area is at least twice as high as the original, and the corresponding echo amplitude multiple increases, it is preliminarily determined to be a sensitive state.

4. The electromagnetic sensitivity determination method based on critical state dot trace echo display according to claim 1, characterized in that: In step 3, reasonable sensitive phenomena include sensitivity caused by non-effective interference signals of the test equipment, sensitivity caused by interference signals within the RF bandwidth of the tested radar, sensitivity caused by interference signals within the radar RF frequency range generated by the test equipment itself, sensitivity caused by interference signals generated by the harmonics of the interference signals entering the radar RF range, sensitivity caused by interference signals generated by the noise of the power amplifier itself, and sensitivity caused by interference signals that can be removed by anti-interference measures taken on the basis of ensuring the functional performance of the radar.

5. The electromagnetic sensitivity determination method based on critical state dot trace echo display according to claim 4, characterized in that: The specific steps to eliminate the sensitivity caused by the ineffective interference signal of the test equipment are as follows: reproduce the test scene, including the layout of surrounding objects, the status of the test equipment, and personnel changes; if the sensitive phenomenon reappears, adjust the object that can reflect the signal into the radar receiving channel and observe the sensitivity changes; find the signal source of the reflector. Once it is found that adjusting a certain reflective object can cause sensitive changes, further use the same method to find the signal source of the reflector; repeat the above operations, gradually eliminate the influence of other factors, and finally find the ineffective interference signal of the test equipment.

6. The electromagnetic sensitivity determination method based on critical state dot trace echo display according to claim 4, characterized in that: The specific steps to eliminate the sensitivity caused by interference signals within the RF bandwidth of the tested radar are as follows: determine whether the frequency of the interference signal belongs to the protection range of the radar RF range. If it belongs to the frequency range with a bandwidth extended by 2 times above and below the radar carrier frequency range, it is an interference signal within the RF bandwidth of the tested radar.

7. The electromagnetic sensitivity determination method based on critical state dot trace echo display according to claim 4, characterized in that: The specific steps to eliminate the sensitivity caused by the interference signal within the radar RF frequency range generated by the test equipment itself are as follows: reproduce the test scene, including the surrounding object layout, test equipment status, and personnel changes; if the phenomenon reappears, adjust the status of the test equipment that can transmit signals into the radar receiving channel, and observe the changes in sensitivity; if the sensitivity phenomenon is weakened by more than half or disappears when the test equipment is turned off, it is judged to be related to the test equipment; if the test equipment is not a necessary device that needs to inject interference signals into the radar, remove the equipment and re-test or determine that the sensitivity is invalid.

8. The electromagnetic sensitivity determination method based on critical state dot trace echo display according to claim 4 is characterized in that: The specific steps to eliminate the sensitivity caused by the interference signal generated by the interference signal harmonics entering the radar radio frequency range are as follows: calculate whether the integer multiples of the interference signal frequency belong to the frequency bandwidth range of the radar's current operation, and if so, preliminarily determine that it is a certain multiple harmonic generation of the interference signal; further test the harmonic signal through the receiving antenna and spectrum analyzer equipment, adjust the spectrum analyzer test frequency band range to include the radar's current radio frequency bandwidth range, and measure the strength of the multiple harmonic signals generated by the interference signal and the ratio of the environmental noise; If the amplitude is more than twice the noise amplitude of the surrounding environment, it is determined that the interference signal is sensitive to the multiple harmonics entering the radar operating frequency band.

9. The electromagnetic sensitivity determination method based on critical state dot trace echo display according to claim 4, characterized in that: The specific steps to eliminate the sensitivity caused by the interference signal generated by the noise of the power amplifier itself are as follows: after the interference signal power amplifier and the transmitting antenna are turned on, the radar screen can show obvious interference enhancement no matter which frequency the power amplifier works at; through the receiving antenna and spectrum analyzer equipment test, adjust the receiving frequency range on the spectrum analyzer to include the current RF bandwidth range of the radar, measure the intensity of the interference signal, and compare it with the environmental noise after turning off the power amplifier; if the amplitude is more than twice the noise amplitude of the surrounding environment, it is determined that the interference noise generated by the power amplifier itself generated by the interference signal has entered the radar working frequency band and caused sensitivity.

10. The electromagnetic sensitivity determination method based on critical state dot trace echo display according to claim 4, characterized in that: The specific steps to eliminate the sensitivity caused by interference signals that can be removed by anti-interference measures taken on the basis of ensuring the functional performance of the radar are as follows: during the test of the power and accuracy indicators of the radar equipment, the signal processing settings are statistically analyzed to obtain the specific setting parameters of the anti-interference measures that do not affect the functional performance of the radar; when encountering sensitive situations, the specific setting parameters of the anti-interference measures that do not affect the functional performance of the radar are adopted. The interference signals that can be eliminated by the radar's own anti-interference measures are reasonable electromagnetic sensitivities, and such interference signals are eliminated.

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