Target indication method based on MEMS attitude sensor and operation device

Abstract

The invention relates to the technical field of target indication, in particular to a target indication method based on an MEMS attitude sensor and an operation device, after software and hardware initialization, calibration beacon confirmation is carried out, then the operation device enters a static standby state, if unmanned aerial vehicle target information is received, the position of a target begins to be calculated immediately, and the position of the target is calculated; after the position information of the target is calculated, the attitude angle difference value of the target relative to the operation device is calculated in combination with the MEMS attitude sensor, the difference value is displayed on the display device, an operator aims at the target of the unmanned aerial vehicle according to an instruction on the display device, and if the target is not successfully processed within the set time, the target is not successfully processed. If not, the operation device needs to pass through a primary zero switch to recalibrate the MEMS attitude sensor. And if the processing is successful, the operation device is switched to the zero position switch again, and the operation device enters a standby working state. According to the invention, the MEMS sensor with low cost is used, and the requirement of long-time use of the target indication system of the unmanned aerial vehicle is met.

Description

Technical Field

[0001] The present invention relates to the technical field of target indication, and in particular to a target indication method and an operating device based on a MEMS attitude sensor. Background Art

[0002] The rapid development of the low-altitude economy has led to the widespread use of drones in all walks of life, and the resulting airspace management issues are increasing. In certain specific places, drones illegally invade controlled airspace, which will not only disrupt aviation order, but may also seriously endanger public safety.

[0003] In order to meet the increasingly urgent needs of drone air defense, target indication systems for drone prevention and control are gradually being used in various scenarios that require controlled airspace.

[0004] In the prior art, traditional target indication systems generally use high-precision inertial navigation systems or dual-antenna satellite positioning and orientation technology to obtain their own attitude. However, the cost of using high-precision inertial navigation systems is extremely high, and dual-antenna satellite positioning and orientation technology has high requirements for satellite signals, is easily affected by signal interference, and has a low output data frequency. However, due to the limited performance of low-cost MEMS (Micro Electromechanical System) sensors, autonomous initial alignment cannot be completed, and there are accumulated errors during use, which makes it difficult to meet actual needs. Summary of the invention

[0005] The purpose of the present invention is to provide a target indication method and operating device based on a MEMS attitude sensor, which utilizes geodetic methods to initially align and maintain the MEMS sensor, and utilizes a kinematic model to predict and associate the trajectory of a UAV target, thereby meeting the needs of a UAV target indication system at a low cost.

[0006] To achieve the above object, the present invention provides a target indication method based on a MEMS attitude sensor, comprising the following steps:

[0007] Step 1: Select a location as the calibration beacon location, mark it with a sighting sign, and obtain the high-precision geographic location of the point in advance through RTK measurement;

[0008] Step 2: Arrange the operating device several meters away from the calibration beacon to ensure that the calibration beacon is within the visual range of the aiming device;

[0009] Step 3: Adjust the aiming device and zero switch of the operating device to aim directly at the calibration beacon, and manually input or send the geographical coordinates of the calibration beacon by the system;

[0010] Step 4: Start the operating device, wait for the GNSS positioning device RTK to complete the fixed solution, manually input or send the calibration beacon geographic location from the upper system, confirm the aiming again, calculate the initial azimuth through the operating device and the calibration beacon geographic location, and pass it to the MEMS attitude sensor to complete the initial azimuth alignment;

[0011] Step 5: During the operation of the operating device, depending on the performance of the MEMS attitude sensor, it is necessary to pass through the zero switch at regular intervals to recalibrate the azimuth angle;

[0012] Step 6: The radar detection end detects the drone target, obtains the drone relative radar information, and sends it to the operating device through the wireless communication device;

[0013] Step 7: After the operating device obtains the relative radar information of the drone, the coordinates of the drone with the operating device as the origin and the relative information of the drone with respect to the operating device are obtained through a coordinate conversion algorithm based on Gauss Kruger projection;

[0014] Step 8: Infer the movement mode of the drone through the recent coordinates of the drone, and then predict the coordinates of the drone target at the next moment, and output the predicted relative information of the next moment in advance;

[0015] Step 9: After obtaining the relative information at the current moment, it is transmitted to the display device, so that the operator can aim at the target using the aiming device.

[0016] Optionally, in step 3, the aiming device of the operating device maintains the same direction as the MEMS gesture sensor, and the operating device maintains the same movement when the entire device rotates.

[0017] Optionally, the GNSS positioning device needs to be set to RTK mode, and the zero switch and the position of the GNSS positioning device do not rotate.

[0018] Optionally, the drone's relative radar information includes the drone's azimuth angle φ relative to the radar, the drone's pitch angle θ relative to the radar, and the drone's slant range R relative to the radar. During the execution of step 6, the drone's relative radar information and the radar's own latitude and longitude coordinates (L1, B1, H1) are sent to the operating device via a wireless communication device.

[0019] The optional coordinate transformation algorithm based on the Gauss-Krüger projection process includes the following steps:

[0020] Step 7.1: Calculate the Gauss-Krüger projection zone number and central meridian of the radar and operating device according to the 6-degree zone, using the following formula:

[0021]

[0022] Where N6 is the 6-degree belt number, L is the longitude, and L6 is the central meridian in the belt. Substituting the latitudes of the radar and the operating device into the above formula, the 6-degree belt number and the central meridian corresponding to the radar and the operating device can be obtained;

[0023] Step 7.2: Determine whether the radar and the operating device are in the same 6-degree zone. If not, calculate the difference between the longitudes of the radar and the operating device and the longitudes of their respective central meridians. Take the point with the smaller difference as the 6-degree zone N0 used in the calculation, and take the central meridian L0 in the zone as the common meridian.

[0024] Calculate the Gauss-Krüger plane coordinates of the radar and the operating device respectively. The conversion formula is as follows:

[0025] Assume the longitude and latitude coordinates of the target point to be converted are (L, B), first calculate the arc length s of the meridian from the latitude of the point to the equator

[0026]

[0027] In the above formula, r is the radius of the major axis of the earth ellipsoid, and e is the first eccentricity of the earth ellipsoid. Then the x and y coordinates of the target point are:

[0028]

[0029] In the above formula, N is the radius of curvature of the y-axis circle, and L0 is the longitude of the central meridian of the target point. In the above formula, δl=L-L0 is the difference between the longitude of the target point and the longitude of the central meridian.

[0030] In the above conversion formula, the ellipsoid parameters involved in the calculation are the WGS-84 coordinate system parameters, the major axis of the earth ellipsoid is r, the ellipsoid flattening is f, the minor axis of the ellipsoid is b, the first eccentricity of the ellipsoid is e, the second eccentricity is e′, and the radius of curvature of the ellipse is N. The calculation parameters and formulas are as follows:

[0031]

[0032] Substitute the geographic coordinate parameters of the radar and the operating device, as well as the central meridian obtained in step 7.1, into the above conversion formula to obtain the Gauss Kruger projection coordinates corresponding to the radar and the operating device;

[0033] Step 7.4: Calculate the coordinates of the radar and the operating device in the Gauss Kruger plane rectangular coordinate system, radar coordinates (X1, Y1), operating device coordinates (X2, Y2), let the geodetic height H of these two points be the Z axis, and the extended Gauss Kruger projection coordinate system can be obtained, and the radar coordinates (X1, Y1, Z1) and operating device coordinates (X2, Y2, Z2) can be obtained; according to the information of the drone relative to the radar, the coordinates of the drone in the extended Gauss Kruger coordinate system can be calculated as:

[0034]

[0035] Based on the extended Gauss Kruger coordinate system, the X axis is taken as the east direction, the Y axis is taken as the north direction, the X axis is taken as the east direction, and the Z axis is taken as the sky direction, and the northeast sky coordinate system with the operating device as the origin can be obtained;

[0036] The coordinates of the drone target in the northeast sky coordinate system can be obtained as follows:

[0037]

[0038] Step 7.5: Use the meridian convergence angle to correct the coordinates and obtain the corrected radar coordinates (X'1, Y'1, Z'1), operating device coordinates (X'2, Y'2, Z'2), and drone coordinates (X'3, Y'3, Z'3);

[0039] Step 7.6: Obtain the azimuth angle of the drone relative to the operating device through geometric calculation Pitch angle θ', slant range R'.

[0040] Optionally, in the process of drone track association and track prediction in step 8, the displacement between each two consecutive points is calculated in the three-dimensional coordinates of the northeast celestial coordinate system with the operating device as the origin, and the speed and acceleration at the current moment are obtained based on the constant data interval, and the motion state of the drone in the three-dimensional coordinate system at the current moment is calculated.

[0041] The present invention also proposes a target indication operating device based on a MEMS attitude sensor, which is used for the target indication method based on a MEMS attitude sensor, including a single-chip microcomputer, a GNSS positioning device, a MEMS attitude sensor, a sighting device, a display device and a zero position switch. The zero position switch is used to recalibrate the MEMS attitude sensor. After the operating device receives the drone target position data, the single-chip microcomputer is used to process the data, and at the same time, the MEMS attitude sensor and the GNSS positioning device are combined to obtain the attitude information of the drone target relative to the operating device, and send it to the display device. Then the operator can use the sighting device to track the drone according to the instructions of the display device.

[0042] The present invention provides a target indication method and operating device based on a MEMS attitude sensor. After the software and hardware are initialized, a calibration beacon is confirmed, and then the operating device enters a static standby state. If the target information of the UAV is received, the position of the target is calculated immediately. After the target position information is calculated, the attitude angle difference of the target relative to the operating device is calculated in combination with the MEMS attitude sensor, and the difference is displayed on a display device. The operator aims at the UAV target according to the instructions on the display device. If the target is not successfully processed within the specified time, the operating device needs to be recalibrated by passing the zero switch once. If the processing is successful, the operating device is turned back to the zero switch, and the operating device enters a standby working state. The present invention optimizes the coordinate conversion algorithm based on the Gauss Kruger projection, and uses the kinematic model to predict and associate the track of the UAV target, meeting the demand for long-term use of the UAV target indication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a schematic diagram of the steps of a target indication method based on a MEMS attitude sensor of the present invention.

[0045] Figure 2 It is a schematic diagram of the system structure of a target indication method based on a MEMS attitude sensor of the present invention.

[0046] Figure 3 It is a schematic diagram of the working process of a target indication operation device based on a MEMS attitude sensor of the present invention. DETAILED DESCRIPTION

[0047] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0048] See also Figure 1 The present invention provides a target indication method based on a MEMS attitude sensor, comprising the following steps:

[0049] S1: Select a location as the calibration beacon location, mark it with a sighting sign, and obtain the high-precision geographic location of the point in advance through RTK measurement;

[0050] S2: Arrange the operating device several meters away from the calibration beacon to ensure that the calibration beacon is within the visual range of the aiming device;

[0051] S3: Adjust the aiming device and the zero switch of the operating device to aim at the calibration beacon, and input the geographical location coordinates of the calibration beacon manually or through the system;

[0052] S4: Start the operating device, wait for the GNSS positioning device RTK to complete the fixed solution, manually input or send the calibration beacon geographic location from the upper system, confirm the aiming again, calculate the initial azimuth through the operating device and the calibration beacon geographic location, and pass it to the MEMS attitude sensor to complete the initial azimuth alignment;

[0053] S5: During the operation of the operating device, depending on the performance of the MEMS attitude sensor, it is necessary to pass through the zero position switch at regular intervals to recalibrate the azimuth angle;

[0054] S6: The radar detection end detects the drone target, obtains the drone relative radar information, and sends it to the operating device through the wireless communication device;

[0055] S7: After the operating device obtains the relative radar information of the drone, the coordinates of the drone with the operating device as the origin and the relative information of the drone with respect to the operating device are obtained through a coordinate conversion algorithm based on Gauss Kruger projection;

[0056] S8: infer the movement mode of the drone through the recent coordinates of the drone, and then predict the coordinates of the drone target at the next moment, and output the predicted relative information of the next moment in advance;

[0057] S9: After obtaining the relative information at the current moment, it is transmitted to the display device, so that the operator can aim at the target using the aiming device.

[0058] The present invention also proposes a target indication operating device based on a MEMS attitude sensor, which is used for the target indication method based on a MEMS attitude sensor, including a single-chip microcomputer, a GNSS positioning device, a MEMS attitude sensor, a sighting device, a display device and a zero position switch. The zero position switch is used to recalibrate the MEMS attitude sensor. After the operating device receives the drone target position data, the single-chip microcomputer is used to process the data, and at the same time, the MEMS attitude sensor and the GNSS positioning device are combined to obtain the attitude information of the drone target relative to the operating device, and send it to the display device. Then the operator can use the sighting device to track the drone according to the instructions of the display device.

[0059] like Figure 2 The figure shows the structure of the various parts of the target indication operation device based on MEMS attitude sensor in the whole system.

[0060] In the operating device, the aiming device maintains the same direction as the MEMS attitude sensor, and when the operating device rotates as a whole, it maintains the same movement, and the zero switch and the GNSS positioning device do not rotate.

[0061] The GNSS positioning device in the operating device needs to be set to RTK mode to obtain high-precision geographic location.

[0062] The specific operation process of the device is as follows: Figure 3 As shown, after the system is started, the software and hardware are initialized first, then a check is made to see if there is a calibration beacon. If not, a calibration beacon needs to be arranged, and then the geographical location coordinates (i.e., longitude, latitude and altitude) of the calibration beacon are entered in the operating device, the calibration beacon is aimed at by the aiming device, and the zero position switch is adjusted to the aiming position, and then after confirmation that the calibration is completed, the operating device enters a static standby state.

[0063] If the target information of the UAV is received, the position of the target will be calculated immediately. After the target position information is calculated, the attitude angle difference of the target relative to the device is calculated in combination with the MEMS attitude sensor, and the difference is displayed on the display device. The operator aims at the UAV target according to the instructions on the display device. If the target is not successfully processed within the specified time, the device needs to pass the zero switch once to recalibrate the MEMS attitude sensor. If the processing is successful, the device will be turned back to the zero switch and the device will enter the standby working state.

[0064] The following is a further description of the specific steps of the target indication method based on the MEMS attitude sensor:

[0065] Steps S1 to S5 are the process of initial heading acquisition and subsequent accuracy maintenance of the MEMS attitude sensor, which specifically includes the following steps:

[0066] S1: Select a location as the calibration beacon location, mark it with a sighting card, and obtain the high-precision geographic location of the point in advance through RTK measurement;

[0067] S2: Arrange the operating device several meters away from the calibration beacon to ensure that the calibration beacon is within the visual range of the aiming device.

[0068] S3: Adjust the aiming device of the operating device (in the same direction as the MEMS attitude sensor) and the zero switch to aim directly at the calibration beacon, and manually input or the system sends the geographic location coordinates of the calibration beacon.

[0069] S4: Start the operating device and wait for the GNSS positioning device RTK to complete the fixed solution. Then, manually input the geographic location of the calibration beacon or the system sends it. After confirming the aiming again, calculate the initial azimuth through the geographic location of the operating device and the calibration beacon, and pass it to the MEMS attitude sensor to complete the initial alignment of the azimuth.

[0070] S5: During the operation of the operating device, depending on the performance of the MEMS attitude sensor, it is necessary to pass through the zero position switch at regular intervals to recalibrate the azimuth.

[0071] Steps S6 to S9 are the process of accurately guiding the drone target, which specifically includes the following steps:

[0072] S6: The radar detection end detects the UAV target and obtains the UAV relative radar information, including the azimuth angle φ of the UAV relative to the radar, the pitch angle θ of the UAV relative to the radar, and the slant range R of the UAV relative to the radar. These relative information, including the latitude and longitude coordinates (L1, B1, H1) of the radar itself, are sent to the operating device through the wireless communication device.

[0073] S7: After the operating device obtains the information, the high latitude and longitude coordinates (L2, B2, H2) of the operating device and the geographic location coordinates (L1, B1, H1) of the radar detection end are converted into coordinates in the northeast celestial coordinate system with the operating device as the origin through a coordinate conversion algorithm based on the Gauss Krüger projection. The coordinates of the drone are then calculated using the information of the drone relative to the radar. Finally, the relative information of the drone relative to the operating device can be obtained through geometric calculations.

[0074] S8: After obtaining the coordinates of the drone, the heading ω and acceleration σ of the drone in the northeast celestial coordinate system can be calculated through the coordinates of the most recent few times. This information can be used to infer the movement mode of the drone, and then predict the coordinates of the drone target at the next moment, and output the predicted relative information of the next moment in advance.

[0075] S9: After obtaining the relative information of the drone at the current moment, it is transmitted to the display device, so that the operator can aim at the target using the aiming device.

[0076] In step S7, the specific steps of the coordinate transformation algorithm based on the Gauss Kruger projection are as follows:

[0077] (1) First, calculate the Gauss Krüger projection zone number and central meridian of the radar and operating device, according to the 6-degree zone, and the formula is as follows:

[0078]

[0079] Where N6 is the 6-degree belt number, L is the longitude, and L6 is the central meridian in the belt. Substituting the latitudes of the radar and the operating device into the above formula respectively, the 6-degree belt number and the central meridian corresponding to the radar and the operating device can be obtained.

[0080] (2) Determine whether the radar and the operating device are in the same 6-degree zone. If not, calculate the difference between the longitudes of the radar and the operating device and the longitudes of their respective central meridians. Take the point with the smaller difference as the 6-degree zone N0 used in the calculation, and take the central meridian L0 in the zone as the common meridian.

[0081] (3) Calculate the Gauss-Krüger plane coordinates of the radar and the operating device respectively, the formula is as follows:

[0082] Assume the longitude and latitude coordinates of the target point to be converted are (L, B), first calculate the arc length s of the meridian from the latitude of the point to the equator

[0083]

[0084] In the above formula, r is the radius of the major axis of the earth ellipsoid, and e is the first eccentricity of the earth ellipsoid. Then the x and y coordinates of the target point are:

[0085]

[0086] In the above formula, N is the radius of curvature of the ellipsoid, L0 is the longitude of the central meridian of the target point, δl=L-L0 is the difference between the longitude of the target point and the longitude of the central meridian, the calculated ellipsoid parameters are the WGS-84 coordinate system parameters, the major semi-axis of the earth ellipsoid is r, the flattening of the ellipsoid is f, the minor semi-axis of the ellipsoid is b, the first eccentricity of the ellipsoid is e, and the second eccentricity is e′:

[0087]

[0088] (4) Through (3), the coordinates of the radar and the operating device in the Gauss Kruger plane rectangular coordinate system can be calculated, the radar coordinates (X1, Y1), the operating device coordinates (X2, Y2), now let the geodetic height H of these two points be the Z axis, we can get the extended Gauss Kruger projection coordinate system, we can get the radar coordinates (X1, Y1, Z1), the operating device coordinates (X2, Y2, Z2). According to the information of the drone relative to the radar, the coordinates of the drone in the extended Gauss Kruger coordinate system can be calculated as:

[0089]

[0090] At this point, based on the above-mentioned extended Gauss Kruger coordinate system, with the X axis as the east direction, the Y axis as the north direction, the X axis as the east direction, and the Z axis as the celestial direction, a northeast celestial coordinate system with the operating device as the origin can be obtained.

[0091] The coordinates of the drone target in the northeast sky coordinate system can be obtained as follows:

[0092]

[0093] (5) Since the earth is an ellipsoid, a certain deviation will occur when calculating the Gauss-Krüger projection, resulting in the true meridian and the projected coordinates not coinciding vertically, thus generating the meridian convergence angle, which is calculated as follows:

[0094]

[0095] Where γ is the meridian convergence angle, and φ0 is the latitude of the projection point. Substituting the coordinates of the operating device into the equation, the meridian convergence angle γ0 of the point can be obtained, and the corrected coordinate formula is as follows:

[0096] x'=xcos(γ0)-sin(γ0)

[0097] y'=xsin(γ0)-ycos(γ0)

[0098] Z'=Z

[0099] Substituting the radar, operating device and drone coordinates into the above formula, we can get the corrected radar coordinates (X'1, Y'1, Z'1), operating device coordinates (X'2, Y'2, Z'2), and drone coordinates (X'3, Y'3, Z'3)

[0100] (6) Through geometric calculation, it can be known that the azimuth angle of the drone relative to the operating device The pitch angle θ' and slant range R' are:

[0101]

[0102] In step S8, the specific steps of drone track association and track prediction are as follows:

[0103] Based on the three-dimensional coordinates (X, Y, Z) of n drone targets in the northeastern sky coordinate system with the operating device as the origin, the displacement (Δ X ,Δ Y ,Δ z ), and according to the constant data interval Δ t , get the speed of n at the current time and acceleration and the previous n-1 moments

[0104] Then, based on the speed and acceleration values, the motion state of the drone in the three-dimensional coordinate system at the current moment (uniform motion or uniformly accelerated motion) can be calculated.

[0105] If the target is moving at a constant speed (CV), the target position at the next moment is:

[0106]

[0107] If the target is in uniform acceleration (CA), the target position at the next moment is:

[0108]

[0109] In summary, the present invention has the following beneficial effects:

[0110] (1) The present invention adopts a MEMS attitude sensor to obtain the attitude of the operating device itself, and cooperates with a calibration beacon and a zero position switch to maintain high-precision attitude measurement for a long time. Compared with a high-precision inertial navigation system, it reduces the cost of obtaining the attitude of the operating device. Compared with magnetic orientation and satellite orientation, it improves the data frequency and stability of the operating device.

[0111] (2) The present invention performs secondary processing on the UAV target position information obtained by the radar detection end at the single-chip microcomputer end, takes into account the influence of the meridian convergence angle, optimizes the coordinate transformation algorithm based on the Gauss Krüger projection, and uses the kinematic model to predict and associate the track of the UAV target, which can guide the operator to aim at the UAV target position and speed up the target capture speed.

[0112] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A target indication method based on a MEMS attitude sensor, characterized in that: The following steps are involved: Step 1: Select a location as the calibration beacon location, mark it with a sighting sign, and obtain the high-precision geographic location of the point in advance through RTK measurement; Step 2: Arrange the operating device several meters away from the calibration beacon to ensure that the calibration beacon is within the visual range of the aiming device; Step 3: Adjust the aiming device and zero switch of the operating device to aim directly at the calibration beacon, and manually input or send the geographical coordinates of the calibration beacon by the system; Step 4: Start the operating device, wait for the GNSS positioning device RTK to complete the fixed solution, manually input or send the calibration beacon geographic location from the upper system, confirm the aiming again, calculate the initial azimuth through the operating device and the calibration beacon geographic location, and pass it to the MEMS attitude sensor to complete the initial azimuth alignment; Step 5: During the operation of the operating device, depending on the performance of the MEMS attitude sensor, it is necessary to pass through the zero switch at regular intervals to recalibrate the azimuth angle; Step 6: The radar detection end detects the drone target, obtains the drone relative radar information, and sends it to the operating device through the wireless communication device; Step 7: After the operating device obtains the relative radar information of the drone, the coordinates of the drone with the operating device as the origin and the relative information of the drone with respect to the operating device are obtained through a coordinate conversion algorithm based on Gauss Kruger projection; Step 8: Infer the movement mode of the drone through the recent coordinates of the drone, and then predict the coordinates of the drone target at the next moment, and output the predicted relative information of the next moment in advance; Step 9: After obtaining the relative information at the current moment, it is transmitted to the display device, so that the operator can aim at the target using the aiming device.

2. The target indication method based on MEMS attitude sensor according to claim 1, characterized in that: In step 3, the aiming device of the operating device is kept in the same direction as the MEMS attitude sensor, and the operating device maintains the same movement when it rotates as a whole.

3. The target indication method based on MEMS attitude sensor as claimed in claim 2, characterized in that: The GNSS positioning device needs to be set to RTK mode, and the zero switch and the position of the GNSS positioning device do not rotate.

4. The target indication method based on MEMS attitude sensor as claimed in claim 3, characterized in that: The drone relative radar information includes the azimuth angle φ of the drone relative to the radar, the pitch angle θ of the drone relative to the radar, and the slant range R of the drone relative to the radar. During the execution of step 6, the drone relative radar information and the longitude and latitude high coordinates (L1, B1, H1) of the radar itself are sent to the operating device via a wireless communication device.

5. The target indication method based on MEMS attitude sensor as claimed in claim 4, characterized in that: The process of coordinate transformation algorithm based on Gauss-Krüger projection includes the following steps: Step 7.1: Calculate the Gauss-Krüger projection zone number and central meridian of the radar and operating device according to the 6-degree zone, using the following formula: Where N6 is the 6-degree belt number, L is the longitude, and L6 is the central meridian in the belt. Substituting the longitudes of the radar and the operating device into the above formula, the 6-degree belt number and the central meridian corresponding to the radar and the operating device can be obtained; Step 7.2: Determine whether the radar and the operating device are in the same 6-degree zone. If not, calculate the difference between the longitudes of the radar and the operating device and the longitudes of their respective central meridians. Take the point with the smaller difference as the 6-degree zone N0 used in the calculation, and take the central meridian L0 in the zone as the common meridian. Step 7.3: Calculate the Gauss-Krüger plane coordinates of the radar and the operating device respectively. The conversion formula is as follows: Assume the longitude and latitude coordinates of the target point to be converted are (L, B), first calculate the arc length s of the meridian from the latitude of the point to the equator In the above formula, r is the radius of the major axis of the earth ellipsoid, and e is the first eccentricity of the earth ellipsoid. Then the x and y coordinates of the target point are: In the above formula, N is the radius of curvature of the y-axis circle, and L0 is the longitude of the central meridian of the target point. In the above formula, δl=L-L0 is the difference between the longitude of the target point and the longitude of the central meridian. In the above conversion formula, the ellipsoid parameters involved in the calculation are the WGS-84 coordinate system parameters, the major axis of the earth ellipsoid is r, the ellipsoid flattening is f, the minor axis of the ellipsoid is b, the first eccentricity of the ellipsoid is e, the second eccentricity is e′, and the radius of curvature of the ellipse is N. The calculation parameters and formulas are as follows: Substitute the geographic coordinate parameters of the radar and the operating device, as well as the central meridian obtained in step 7.1, into the above conversion formula to obtain the Gauss Kruger projection coordinates corresponding to the radar and the operating device; Step 7.4: Calculate the coordinates of the radar and the operating device in the Gauss Kruger plane rectangular coordinate system, radar coordinates (X1, Y1), operating device coordinates (X2, Y2), let the geodetic height H of these two points be the Z axis, and the extended Gauss Kruger projection coordinate system can be obtained, and the radar coordinates (X1, Y1, Z1) and the operating device coordinates (X2, Y2, Z2) can be obtained; according to the information of the drone relative to the radar, the coordinates of the drone in the extended Gauss Kruger coordinate system can be calculated as: Based on the extended Gauss Kruger coordinate system, the X axis is taken as the east direction, the Y axis is taken as the north direction, the X axis is taken as the east direction, and the Z axis is taken as the sky direction, and the northeast sky coordinate system with the operating device as the origin can be obtained; The coordinates of the drone target in the northeast sky coordinate system can be obtained as follows: Step 7.5: Use the meridian convergence angle to correct the coordinates and obtain the corrected radar coordinates (X'1, Y'1, Z'1), operating device coordinates (X'2, Y'2, Z'2), and drone coordinates (X'3, Y'3, Z'3); Step 7.6: Obtain the azimuth angle of the drone relative to the operating device through geometric calculation Pitch angle θ', slant range R'.

6. The target indication method based on MEMS attitude sensor as claimed in claim 5, characterized in that: In the process of drone track association and track prediction in step 8, the displacement between each two consecutive points is calculated in the three-dimensional coordinates of the northeast celestial coordinate system with the operating device as the origin, and the speed and acceleration at the current moment are obtained based on the constant data interval, and the motion state of the drone in the three-dimensional coordinate system at the current moment is calculated.

7. A target indication operation device based on a MEMS attitude sensor, used in the target indication method based on a MEMS attitude sensor as claimed in any one of claims 1 to 6, characterized in that: It includes a single-chip microcomputer, a GNSS positioning device, a MEMS attitude sensor, a sighting device, a display device and a zero position switch. The zero position switch is used to recalibrate the MEMS attitude sensor. After the operating device receives the UAV target position data, the single-chip microcomputer is used to process the data. At the same time, the MEMS attitude sensor and the GNSS positioning device are combined to obtain the attitude information of the UAV target relative to the operating device, and send it to the display device. Then the operator can use the sighting device to track the UAV according to the instructions of the display device.

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