Three-dimensional power map calibration method and device based on unmanned aerial vehicle target simulator

Abstract

The present invention provides a three-dimensional power map calibration method and device based on an unmanned aerial vehicle (UAV)-mounted target simulator. The method includes: a receiving antenna receives a radio frequency signal from a radar under test, which is then fed into a target simulator host for mixing and amplification to convert it into an intermediate frequency signal. The intermediate frequency signal undergoes analog-to-digital conversion to convert it into a digital signal, which is then digitally down-converted to convert it into a baseband signal. The device host modulates the baseband signal by amplitude, speed, and distance to generate a baseband target analog signal. The baseband target analog signal undergoes digital up-conversion and digital-to-analog conversion to convert it into an intermediate frequency analog signal. The intermediate frequency analog signal undergoes mixing and amplification to convert it into a radio frequency signal. The radio frequency signal is fed into a transmitting antenna via an RF cable and radiated toward the radar under test, thereby generating the required simulated target signal on the radar under test. This inventive method can achieve high-precision calibration of a radar's three-dimensional power map in a real-world scenario using a low-cost UAV platform equipped with a target simulator, through scaled measurement.

Description

Technical Field

[0001] The present invention relates to the fields of electronic technology and radar technology, and more particularly to a three-dimensional power map calibration method and device based on an unmanned aerial vehicle (UAV)-mounted target simulator. Background Art

[0002] Radar can acquire target information around the clock and is essential for meteorological services, aviation, and ship traffic control. Radar detection range, also known as radar power range, refers to the airspace within which the radar continuously observes the target. Determining the effective detection range of a radar helps operators understand the electromagnetic situation in real time, enhances information-based decision-making, and provides a crucial foundation for mission planning.

[0003] There are three common ways to obtain a radar power diagram. The first is to estimate it through numerical simulation using radar equations, radar antenna patterns, and clutter models. The second is to obtain the radar power diagram through radar flight tests at a flight test site. The third is to record measured data from various targets during radar operation and continuously modify the radar power diagram based on this data combined with theoretical models to obtain the radar power diagram for the current state.

[0004] The first numerical simulation method is simple, convenient, and low-cost, but it struggles to accurately simulate the real electromagnetic environment, resulting in large errors. The simulation results can only be used as a reference. Furthermore, as radars age, problems such as reduced transmit power and antenna beam deformation can occur. Therefore, numerical simulation alone cannot accurately capture changes in radar detection power. The second radar flight test method places high demands on factors such as target flight attitude, track selection, and the environment. It is also expensive, involves numerous coordination issues, and has poor engineering practicality. The third method, which uses radar measured data combined with theoretical models for estimation, requires extensive data accumulation to obtain a radar power map, which is time-consuming. Furthermore, the accumulated measured data needs to be continuously updated and maintained, making implementation equally challenging. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method and device for calibrating a three-dimensional radar power map using a drone-mounted target simulator. This method uses a low-cost drone platform equipped with a target simulator to achieve high-precision calibration of radar three-dimensional power maps through scaled measurement in real-world scenarios.

[0006] According to a first aspect of the present invention, a method for calibrating a three-dimensional power chart based on an unmanned aerial vehicle (UAV) target simulator is provided. The method comprises the following steps:

[0007] Step 1: Calibrate the radar cross-section of the target simulator;

[0008] Step 2: The drone takes off with the target simulator, flies to the set position and hovers, and the radar and target simulator enter standby mode;

[0009] Step 3: Adjust the drone's attitude so that the radar and simulator main lobes are aligned with each other;

[0010] Step 4: The radar and target simulator enter working state. The target simulator receives the radar signal and generates a target simulation signal to be transmitted to the radar.

[0011] Step 5: The radar receives the target simulation signal and the radar screen displays the radar detection results;

[0012] Step 6: The target simulator sets the link gain to decrease in steps;

[0013] Step 7: The radar monitors the changes in the simulated target. When the simulated target disappears from the target, it is the limit of the radar detection power. The link gain value on the current target simulator is recorded, and the radar detection power limit of the current position and direction is calculated.

[0014] Step 8: Control the radar beam to scan, and at the same time control the drone to fly to the beam pointing position according to the flight trajectory. Repeat steps 3 to 7 to measure the detection limit when the radar points to other azimuth angles and record them. The azimuth measurement range must be greater than the azimuth detection range of the radar.

[0015] Step 9: The drone changes its flight altitude and repeats steps 3 to 8 to measure the detection power of targets at other altitudes. The detection altitude range must cover the radar's pitch detection range.

[0016] Step 10: After multiple height detections are completed, obtain the radar detection power in the altitude and azimuth directions, and generate the target radar cross-sectional area in Nm based on the recorded results. 2 The three-dimensional power diagram of the radar is used, and the sizes of other radar scattering cross-sections are converted in proportion according to the three-dimensional power diagram of the predetermined target radar.

[0017] Optionally, the offline calibration of the radar cross-section of the target simulator includes:

[0018] Step a: The target simulator is placed on the distance vector network analyzer R m At the output port of the vector network analyzer, connect the standard horn antenna to transmit the signal;

[0019] Step b: The target simulator stores samples of the received signal, and the vector network analyzer stops transmitting the signal;

[0020] Step c: Connect the standard horn antenna to the receiving port of the vector network analyzer;

[0021] Step d: the target simulator starts to send a target analog signal that is not amplitude modulated;

[0022] Step e: Calculate the signal power E1 on the vector network analyzer;

[0023] Step f: Calculate the equivalent radar cross-section in Nm 2 When the target simulator is placed on the distance vector network analyzer R m When the network is lost, the signal power received is E2;

[0024] Step g: the target simulator restarts sending the target simulation signal, and adjusts the link gain of the target simulator, which is displayed on the vector network analyzer so that E1 = E2;

[0025] Step h: Record the link gain setting value m at this time, that is, the radar distance to the target simulator is R m , and when the target simulator sets the link gain to m, the target radar cross-sectional area simulated by the target simulator is Nm 2 , offline calibration is completed.

[0026] Optionally, in step e, the expression of the power E1 is:

[0027]

[0028] Among them, P l is the vector network analyzer signal transmission power; G l is the standard horn antenna gain; m is the target simulator link gain, which is adjustable; R m is the distance between the receiving horn antenna and the simulator; σ er is the equivalent radar cross-sectional area of the target simulated by the target simulator; A e is the receiving aperture of the standard horn antenna; λ is the signal wavelength; a l It is the insertion loss of the RF cable from the antenna port to the vector network analyzer, and the value can be measured in advance.

[0029] Optionally, in step f, according to the radar equation, the radar cross-sectional area is 1m 2 The power of the target reflected echo signal received by the above standard horn antenna and vector network analyzer is

[0030]

[0031] in, Expressed as radar cross section, the value is 1, P l is the vector network analyzer signal transmission power; G l is the gain of the standard horn antenna; R m is the distance between the receiving horn antenna and the simulator; λ is the signal wavelength; a lIt is the insertion loss of the RF cable from the antenna port to the vector network analyzer, and the value can be measured in advance.

[0032] Optionally, the radar monitors the change of the simulated target. When the simulated target disappears from the target, it is the limit of the radar detection power. The link gain value on the current target simulator is recorded, and the radar detection power limit of the current position and orientation is calculated.

[0033] Calculate the radar cross-sectional area corresponding to the link gain value n;

[0034] According to the radar equation, the radar reflection cross-sectional area is Nm under the detection limit. 2 The power of the target's transmitted signal to the radar

[0035] According to the radar distance equation, calculate the power Pr of the current simulated target reaching the radar;

[0036] When P r =P rmin When , find the radar detection limit.

[0037] Optionally, the power According to the following formula:

[0038]

[0039] Among them, P t is the radar transmission power; G t is the radar antenna gain; R max is the detection power of the radar in the current direction;

[0040] Optionally, according to the radar range equation, the power P of the current simulated target reaching the radar r for:

[0041]

[0042] Among them, σ m is the equivalent cross-sectional area corresponding to the target simulator link gain setting value n.

[0043] According to a second aspect of the present invention, there is also provided a three-dimensional power map calibration device based on an unmanned aerial vehicle target simulator, comprising:

[0044] The target simulator mainly includes a target simulator device host, a transceiver antenna, a data transmission, and a ground display and control part. The transceiver antenna can adopt a single antenna method with both transceivers and receivers, or a dual antenna method with both transceivers and receivers separated.

[0045] The target simulator is carried on the unmanned aerial vehicle and can align the radar beam and the target simulator beam with each other through attitude adjustment.

[0046] Optionally, after receiving the radar signal to be measured, the transceiver antenna transmits the signal to the target simulator host through the device cable, and the signal is mixed and amplified inside the target simulator host to be converted into an intermediate frequency signal, the intermediate frequency signal is converted into a digital signal after analog-to-digital conversion, and the digital signal is converted into a baseband signal after digital down-conversion;

[0047] The device host modulates the baseband signal by amplitude, speed, and distance to generate a corresponding baseband target analog signal. The baseband target analog signal is converted into an intermediate frequency analog signal after digital up-conversion and digital-to-analog conversion. The intermediate frequency analog signal is converted into an radio frequency signal after mixing and amplification. The radio frequency signal is sent to the transmitting antenna through the radio frequency cable and radiated toward the radar to be tested, thereby generating the required analog target signal on the radar to be tested.

[0048] Technical effects and advantages of the present invention:

[0049] (1) The present invention uses a low-cost UAV platform equipped with a target simulator to achieve high-precision calibration of the radar's three-dimensional power map through scaled measurement. This is low-cost, avoids the complex radar flight test process, and does not require the accumulation of a large amount of radar usage data.

[0050] (2) The present invention provides a radar cross-sectional area calibration method for a target simulator, which has high accuracy and simple operation;

[0051] (3) The radar power chart calibration method provided by the present invention can be used to test the overall performance indicators of the radar, so that technical personnel can understand the radar performance status in a timely manner. On the other hand, it can be used to carry out practical exercises to improve the operational proficiency and technical level of radar operators.

[0052] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic diagram of the radar cross-sectional area of an offline calibration target simulator provided by an embodiment of the present invention;

[0054] Figure 2 A schematic diagram illustrating the relative positional relationship between a radar and a target simulator provided in an embodiment of the present invention;

[0055] Figure 3A schematic diagram of a single-altitude flight trajectory of a UAV provided in an embodiment of the present invention;

[0056] Figure 4 A schematic diagram of the multi-altitude flight trajectory of a UAV provided in an embodiment of the present invention;

[0057] Figure 5 A schematic diagram of a three-dimensional power map calibration device based on a drone-mounted target simulator provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0058] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0059] It is understandable that, based on the defects in the background technology, the embodiment of the present invention proposes a three-dimensional power map calibration method based on a drone-mounted target simulator, specifically as follows: Figure 1-4 As shown, the steps of locating the three-dimensional power map are as follows:

[0060] Step 1: Offline calibration of the radar cross section of the target simulator;

[0061] In the embodiment of the present invention, the radar cross section of the offline calibration target simulator specifically includes:

[0062] Step a: Place the target simulator on the distance vector network analyzer R m At the output port of the vector network analyzer, connect the standard horn antenna to transmit the signal;

[0063] Step b: instruct the target simulator to store samples of the received signal, and the vector network analyzer to stop transmitting the signal;

[0064] Step c: Connect the standard horn antenna to the receiving port of the vector network analyzer;

[0065] In the embodiment of the present invention, connecting the standard horn antenna to the receiving port of the vector network analyzer is actually to remove the standard horn antenna from the output end of the lost network and then connect it to the input end of the lost network.

[0066] Step d: instructing the target simulator to start transmitting the target analog signal which has not been amplitude modulated;

[0067] Step e: Observe the signal power E1 on the vector network analyzer;

[0068] Specifically, in step e: according to the radar equation, the signal power E1 received by the vector network analyzer is:

[0069]

[0070] Among them, P l is the vector network analyzer signal transmission power; G l is the standard horn antenna gain; m is the target simulator link gain, which is adjustable; R m is the distance between the receiving horn antenna and the simulator; σ er is the equivalent radar cross-sectional area of the target simulated by the target simulator; A e is the receiving aperture of the standard horn antenna; λ is the signal wavelength; a l It is the insertion loss of the RF cable from the antenna port to the vector network analyzer, and the value can be measured in advance.

[0071] Step f: Calculate the equivalent radar cross-section in Nm 2 When the target simulator is placed on the distance vector network analyzer R m When the network is lost, the signal power received is E2;

[0072] It should be noted that the radar cross section N can be 1, 2, 3, 4, etc. For ease of understanding, in the embodiment of the present invention, the radar cross section is set to 1m 2 Calculate the equivalent radar cross-sectional area; according to the radar equation, the radar equivalent cross-sectional area can be 1m 2 The target reflected signal, after passing through the above standard horn antenna and vector network analyzer, receives the power of

[0073]

[0074] in, Expressed as a constant; P l is the vector network analyzer signal transmission power; G l is the gain of the standard horn antenna; R m is the distance between the receiving horn antenna and the simulator; a l It is the insertion loss of the RF cable from the antenna port to the vector network analyzer, and the value can be measured in advance.

[0075] Step g: The target simulator starts sending the target simulation signal again, and the link gain of the target simulator is adjusted and observed on the vector network analyzer so that E1 = E2;

[0076] Step h: Record the link gain setting value m at this time, that is, the radar distance to the target simulator is R m, and when the link gain of the target simulator is set to m, the equivalent radar cross-sectional area of the simulated target echo signal is 1m 2 At this time, the target radar cross-sectional area simulated by the target simulator is 1m 2 , offline calibration is completed.

[0077] It should be noted that the target radar cross-section simulated by the target simulator includes but is not limited to 1m 2 , can be set arbitrarily according to actual needs. In the embodiment of the present invention, the radar cross section is 1m 2 An exemplary description is given.

[0078] Step 2: The UAV takes off with the target simulator, flies to the set position and hovers. The radial distance is R, and the radar and target simulator are turned on and enter the standby state.

[0079] Step 3: Adjust the drone's attitude so that the radar and simulator main lobes are aligned with each other;

[0080] Step 4: Operate the radar and target simulator to enter working state. The target simulator receives the radar signal and generates a target simulation signal to be transmitted to the radar.

[0081] Step 5: Observe the radar detection results from the radar screen. At this time, two targets are observed on the radar screen. One target is the real composite echo of the UAV and the target simulator, and the other is a simulated echo. The simulated echo corresponds to a target farther away.

[0082] Step 6: Set the link gain step reduction in the target simulator software interface. The step value and step time are required to be configurable. The step value represents the link gain step interval (in dB) for each step, and the step time represents the switching time interval between two step values.

[0083] Step 7: Observe the changes in the simulated target on the radar screen. When the simulated target changes from presence to absence, it corresponds to the radar detection power limit. Record the link gain value n on the current target simulator and calculate the radar detection power limit at the current position and orientation using the following method.

[0084] The radar cross-section corresponding to the link gain value n is

[0085]

[0086] In the above formula, σ m is the equivalent cross-sectional area corresponding to the target simulator link gain setting value of n, and m is the target simulator link gain, which is adjustable.

[0087] According to the radar distance formula, under the detection limit, the radar cross-sectional area is 1m 2The power of the target transmission signal reaching the radar is:

[0088]

[0089] Among them, P t is the radar transmission power; G t is the radar antenna gain; R max It is the detection power of the radar in the current direction.

[0090] According to the radar range equation, the power of the current simulated target reaching the radar is:

[0091]

[0092] The current simulated target adjusts the radar cross-sectional area value to simulate the situation when the radar reaches the limit detection distance, that is, the scaled simulation. At this time, P r =P rmin , then we can calculate

[0093]

[0094] The detection limit is then:

[0095]

[0096] Step 8: Control the radar beam to scan, and at the same time control the drone to fly to the beam pointing position according to the flight trajectory. Repeat steps 3 to 7 to measure the detection limit when the radar points to other azimuth angles and record them. The azimuth measurement range must be greater than the azimuth detection range of the radar.

[0097] Step 9: Control the drone to change the flight altitude and repeat steps 3 to 8 to measure the detection power of targets at other altitudes. The detection altitude range must cover the radar's pitch detection range.

[0098] Step 10: After multiple height detections are completed, obtain the radar detection power in the altitude and azimuth directions, and generate the target radar cross-sectional area in Nm based on the recorded results. 2 Radar three-dimensional power diagram, radar cross-section for other sizes can be based on Nm 2 Proportional conversion of radar three-dimensional power diagram.

[0099] It should be noted that the radar cross section N can be 1, 2, 3, 4, etc. For ease of understanding, in the embodiment of the present invention, the radar cross section is set to 1m 2 Provide an example description.

[0100] In addition, the embodiment of the present invention also provides a radar three-dimensional power map calibration device based on an unmanned aerial vehicle target simulator, specifically as follows Figure 5 Shown, including:

[0101] The target simulator mainly includes a target simulator device host, a transceiver antenna, a data transmission, and a ground display and control part, wherein the transceiver antenna adopts a single antenna mode with both transceivers shared or a dual antenna mode with both transceivers separated;

[0102] The target simulator is carried on the unmanned aerial vehicle and can align the radar beam and the target simulator beam with each other through attitude adjustment.

[0103] It should be understood that the device described in the embodiment of the present invention first mounts a miniaturized radar target simulator on a drone to achieve accurate and dynamic simulation of the scene in which the target is located, thereby constructing a realistic target environment for the radar and operators.

[0104] The following description uses a dual-antenna approach as an example to provide a detailed description of the target simulator. When the target simulator's transceiver antennas utilize a dual-antenna approach with separate transmitters and receivers, namely, a receiving antenna and a transmitting antenna, the target simulator device host is the core component of the target simulator. After receiving the radar signal under test, the receiving antenna transmits it to the target simulator host via a device cable. Mixing and amplification occur within the target simulator host before converting it into an intermediate frequency (IF) signal. The IF signal undergoes analog-to-digital conversion to a digital signal, which is then digitally down-converted to a baseband signal. The signal processing module within the host chassis modulates the baseband signal for amplitude, speed, and distance according to software-configured parameters to generate a corresponding baseband target analog signal. The baseband target analog signal undergoes digital up-conversion and digital-to-analog conversion to an IF analog signal. The IF analog signal undergoes mixing and amplification to become an RF signal. The RF signal is then transmitted via an RF cable to the transmitting antenna for radiation directed toward the radar under test, thereby generating the desired simulated target signal on the radar under test.

[0105] The target simulator is a miniaturized device that can be mounted on a drone and operates in a frequency band that covers the radar device under test. Its function is to receive signals transmitted by the radar device, modulate the signals, and then forward them to the radar, simulating the radar's return signal. It is required to be able to adjust the power of the forwarded signal, that is, to adjust its own link gain.

[0106] Specifically, the UAV is a low-cost UAV with positioning and attitude adjustment functions, and can align the radar beam and the target simulator beam with each other through attitude adjustment.

[0107] It should be understood that parts not elaborated in detail in this specification belong to the prior art.

[0108] In summary, the three-dimensional power map calibration method and device based on the drone-mounted target simulator provided by the embodiment of the present invention, combined with the maneuverability of the drone platform and the high-precision characteristics of the target simulator in simulating the target, can not only simulate the radar detection situation under real conditions, but also avoid the complicated radar flight test process, with low cost, high precision and simple operation. At the same time, the present invention provides a detailed target simulator radar cross-sectional area calibration and radar power map calibration scheme and theoretical basis. The radar power map calibration method provided by the present invention can be used to test the overall performance indicators of the radar on the one hand, so that relevant personnel can understand the performance status of the radar equipment in a timely manner. On the other hand, it can be used to carry out practical exercises to improve the operational proficiency and technical level of radar operators.

[0109] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A three-dimensional power map calibration method based on an unmanned aerial vehicle target simulator, characterized in that: The calibration method comprises the following steps: Step 1: Calibrate the radar cross section of the target simulator; Step 2: The drone takes off with the target simulator, flies to the set position and hovers, and the radar and target simulator enter standby mode; Step 3: Adjust the drone's attitude so that the radar and simulator main lobes are aligned with each other; Step 4: The radar and target simulator enter working state. The target simulator receives the radar signal and generates a target simulation signal to be transmitted to the radar. Step 5: The radar receives the target simulation signal and the radar screen displays the radar detection results; Step 6: The target simulator sets the link gain to decrease in steps; Step 7: The radar monitors the changes in the simulated target. When the simulated target disappears from the target, it is the limit of the radar detection power. The link gain value on the current target simulator is recorded, and the radar detection power limit of the current position and direction is calculated. Step 8: Control the radar beam to scan, and at the same time control the drone to fly to the beam pointing position according to the flight trajectory. Repeat steps 3 to 7 to measure the detection limit when the radar points to other azimuth angles and record them. The azimuth measurement range must be greater than the azimuth detection range of the radar. Step 9: The drone changes its flight altitude and repeats steps 3 to 8 to measure the detection power of targets at other altitudes. The detection altitude range must cover the radar's pitch detection range. Step 10: After multiple height detections are completed, obtain the radar detection power in the height and azimuth directions, and generate the target radar cross-sectional area in Nm based on the recorded results. 2 The three-dimensional power diagram of the radar is used, and the sizes of other radar scattering cross-sections are converted in proportion according to the three-dimensional power diagram of the predetermined target radar.

2. The three-dimensional power map calibration method based on the UAV-mounted target simulator according to claim 1 is characterized in that: Describing the radar cross-sectional area of the target simulator comprises the following steps: Step a: The target simulator is placed on the distance vector network analyzer R m At the output port of the vector network analyzer, connect the standard horn antenna to transmit the signal; Step b: The target simulator stores samples of the received signal, and the vector network analyzer stops transmitting the signal; Step c: Connect the standard horn antenna to the receiving port of the vector network analyzer; Step d: the target simulator starts to send a target analog signal that is not amplitude modulated; Step e: Calculate the signal power E1 on the vector network analyzer; Step f: Calculate the equivalent radar cross-section in Nm 2 When the target simulator is placed on the distance vector network analyzer R m When the network is lost, the signal power received is E2; Step g: The target simulator starts sending the target simulation signal again, adjusts the target simulator link gain, and displays it on the vector network analyzer so that ; Step h: Record the link gain setting value m at this time, that is, the radar distance to the target simulator is R m , and when the target simulator sets the link gain to m, the target radar cross-sectional area simulated by the target simulator is Nm 2 , offline calibration is completed.

3. The three-dimensional power map calibration method based on the UAV-mounted target simulator according to claim 2 is characterized in that: In the step e, the expression of power E1 is: in, is the vector network analyzer signal transmission power; is the standard horn antenna gain; m is the target simulator link gain, which is adjustable; is the distance between the receiving horn antenna and the simulator; It is the equivalent radar cross-section of the target simulated by the target simulator; A e is the receiving aperture of the standard horn antenna; λ is the signal wavelength; a l It is the insertion loss of the RF cable from the antenna port to the vector network analyzer, and the value can be measured in advance.

4. The three-dimensional power map calibration method based on the UAV-mounted target simulator according to claim 2 is characterized in that: In step f, according to the radar equation, the equivalent radar cross-sectional area is Nm 2 The power of the echo signal reflected by the target and received by the standard horn antenna and vector network analyzer is: in, σ Expressed as radar cross section, the value is 1, is the vector network analyzer signal transmission power; is the standard horn antenna gain; is the distance between the receiving horn antenna and the simulator; λ is the signal wavelength; a l It is the insertion loss of the RF cable from the antenna port to the vector network analyzer, and the value can be measured in advance.

5. The three-dimensional power map calibration method based on the UAV-mounted target simulator according to claim 1 is characterized in that: In step 7, the radar monitors the changes in the simulated target. When the simulated target disappears from the target, it is the limit of the radar detection power. The link gain value on the current target simulator is recorded, and the radar detection power limit of the current position and orientation is calculated. Calculate the radar cross-section corresponding to the link gain value n; According to the radar equation, the radar cross-sectional area is Nm under the detection limit. 2 The power of the target's transmitted signal to the radar ; According to the radar distance equation, calculate the power Pr of the current simulated target reaching the radar; when When , find the radar detection limit.

6. The three-dimensional power map calibration method based on the UAV-mounted target simulator according to claim 5 is characterized in that: The radar cross section is Nm 2 Target, the power of the signal transmitted to the radar According to the following formula: in, is the radar transmit power; is the radar antenna gain; R max is the maximum detection power of the radar in the current direction; λ is the signal wavelength.

7. The three-dimensional power map calibration method based on the UAV target simulator according to claim 5, wherein the power of the current simulated target reaching the radar is calculated according to the radar range equation. Expressed as: in, is the radar transmit power; is the radar antenna gain; is the equivalent cross-sectional area corresponding to the target simulator link gain setting value n, R is the detection power of the radar in the current direction, and λ is the signal wavelength.

8. A three-dimensional power map calibration device based on an unmanned aerial vehicle (UAV) target simulator, applied to a three-dimensional power map calibration method based on an unmanned aerial vehicle (UAV) target simulator according to any one of claims 1 to 7, characterized in that: The calibration equipment includes: The target simulator mainly includes a target simulator device host, a transceiver antenna, a data transmission, and a ground display and control part, wherein the transceiver antenna adopts a single antenna mode with both transceivers shared or a dual antenna mode with both transceivers separated; The target simulator is carried on the unmanned aerial vehicle and can align the radar beam and the target simulator beam with each other through attitude adjustment.

9. The three-dimensional power map mapping device based on the drone-mounted target simulator according to claim 8, characterized in that: After receiving the radar signal to be tested, the transceiver antenna sends it to the target simulator host through the device cable, and is mixed and amplified inside the target simulator host to be converted into an intermediate frequency signal. The intermediate frequency signal is converted into a digital signal after analog-to-digital conversion, and the digital signal is converted into a baseband signal after digital down-conversion; The device host modulates the baseband signal by amplitude, speed, and distance to generate corresponding baseband target analog signals. The baseband target analog signals are converted into intermediate frequency analog signals after digital up-conversion and digital-to-analog conversion. The intermediate frequency analog signals are converted into radio frequency signals after mixing and amplification. The radio frequency signals are sent to the transmitting antenna through the radio frequency cable to radiate towards the radar to be tested, thereby generating the required analog target signals on the radar to be tested.

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