Satellite-borne radar aerial target pitch angle estimation method based on satellite pose

Abstract

The invention discloses a satellite-borne radar air target pitch angle estimation method based on a satellite pose, and the method comprises the steps: selecting the position of a satellite-borne radar, the position of an air target, a projection point of the air target on the ground, and a geocentric position as reference points, and constructing a geometric relation model between the satellite-borne radar and the air target; acquiring a first parameter set and a second parameter set based on the geometrical relationship model; constructing a lower view angle first expression according to the first parameter set, and constructing a lower view angle second expression according to the second parameter set; solving the pitch angle by combining the first expression of the lower view angle and the second expression of the lower view angle; according to the method, the problem that the error of the pitch angle estimation value of the air target is large when the satellite-borne radar carries out attitude transformation is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of satellite-borne radar target tracking, and in particular relates to a satellite-borne radar aerial target pitch angle estimation method based on satellite posture. Background Art

[0002] Spaceborne radars have all-weather, all-day strategic and tactical early warning capabilities, and are not restricted by the curvature of the earth and are not vulnerable to attacks. They play a very important role in early warning and defense systems. When a single spaceborne radar tracks and locates an aerial target, the error in measuring the pitch angle of the aerial target is generally larger than the error in measuring the radial distance and azimuth of the aerial target, resulting in large errors in tracking and positioning the aerial target, and is not conducive to identifying the attributes of the aerial target and estimating the threat.

[0003] To solve the problem of large pitch angle measurement error, the altitude of the aerial target is generally estimated first, and then the pitch angle is estimated by geometric methods using the radial distance and azimuth of the aerial target using satellite-borne radar.

[0004] However, when the satellite-borne radar is performing a detection mission, it needs to change its attitude to adapt to the field of view requirements, or it needs yaw guidance to make the Doppler center frequency 0. This makes the pitch angle estimation of the aerial target have a large error when the satellite-borne radar performs complex attitude changes. Summary of the invention

[0005] The purpose of the present invention is to provide a method for estimating the pitch angle of an aerial target of a spaceborne radar based on satellite posture, so as to solve the problem that the pitch angle estimation value of the aerial target has a large error when the spaceborne radar performs attitude change.

[0006] The present invention adopts the following technical solutions:

[0007] A method for estimating the pitch angle of an aerial target of a spaceborne radar based on satellite posture comprises the following steps:

[0008] The position of the satellite-borne radar, the position of the aerial target, the projection point of the aerial target on the ground and the position of the center of the earth are selected as reference points to construct a geometric relationship model between the satellite-borne radar and the aerial target;

[0009] Based on the geometric relationship model, a first parameter set and a second parameter set are obtained; the first parameter set includes the distance from the satellite-borne radar to the center of the earth, the radial distance from the satellite-borne radar to the aerial target, the height of the aerial target and the distance from the projection point to the center of the earth; the second parameter set includes the position of the satellite-borne radar in any celestial body coordinate system, the attitude of the satellite-borne radar in any celestial body coordinate system and the position of the aerial target in any celestial body coordinate system; the position of the aerial target in any celestial body coordinate system is converted into the position of the aerial target in the radar array measurement coordinate system;

[0010] Constructing a first expression of the lower viewing angle according to the first parameter set, and constructing a second expression of the lower viewing angle according to the second parameter set;

[0011] The first expression of the lower viewing angle and the second expression of the lower viewing angle are combined to solve the pitch angle.

[0012] Furthermore, converting the position of the aerial target in any celestial body coordinate system into the position of the aerial target in the radar array measurement coordinate system includes:

[0013] The position of the aerial target in the body coordinate system is calculated according to the position of the spaceborne radar in any celestial body coordinate system, the position of the aerial target in any celestial body coordinate system and the attitude quaternion of the spaceborne radar in any celestial body coordinate system;

[0014] The position of the aerial target in the antenna coordinate system is calculated according to the position of the aerial target in the body coordinate system and the position of the antenna center in the body coordinate system;

[0015] Convert the position of the aerial target in the antenna coordinate system into the position in the radar array measurement coordinate system.

[0016] Furthermore, the first expression of the lower viewing angle is:

[0017]

[0018] Where θ is the arc value of the lower viewing angle, S is the position of the satellite-borne radar, T is the position of the aerial target, G is the projection point of the aerial target on the ground, O is the position of the center of the earth, |OS| is the distance from the satellite-borne radar to the center of the earth, |ST| is the radial distance from the satellite-borne radar to the aerial target, |GT| is the height of the aerial target, and |OB| is the distance from the projection point to the center of the earth.

[0019] Furthermore, the second expression of the lower viewing angle is:

[0020]

[0021] In the formula, is the negative vector of the position vector of the spaceborne radar in any celestial body coordinate system, It is the vector obtained by subtracting the position vector of the satellite-borne radar from the position vector of the aerial target in any celestial coordinate system.

[0022] Furthermore, the method for calculating the altitude of the aerial target includes calculating using micro-multipath measurement of a satellite-borne radar.

[0023] Further, any coordinate system is an ECEF coordinate system.

[0024] Further, any coordinate system is a J2000 coordinate system.

[0025] An electronic device, comprising:

[0026] at least one processor;

[0027] and, a memory communicatively coupled to the at least one processor;

[0028] The memory stores instructions that can be executed by at least one processor, and the instructions are executed by at least one processor so that the at least one processor can execute any one of the above methods for estimating the pitch angle of aerial targets using a satellite-borne radar based on satellite posture.

[0029] The beneficial effect of the present invention is as follows: the present invention constructs a first expression of a lower viewing angle and a second expression of a lower viewing angle based on a geometric relationship model between a satellite-borne radar and an aerial target, and calculates the pitch angle of the aerial target by jointly establishing the first expression of a lower viewing angle and the second expression of a lower viewing angle, wherein the second expression of the lower viewing angle introduces the posture information of the satellite-borne radar, that is, the position of the satellite-borne radar in an ECEF coordinate system or a J2000 coordinate system and the position of the aerial target in an ECEF coordinate system or a J2000 coordinate system, thereby solving the problem of a large error in the estimated value of the pitch angle of the aerial target when the satellite-borne radar performs an attitude transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a flow chart of the method of the present invention;

[0031] Figure 2 A flow chart of a method for converting an aerial target from an ECEF coordinate system or a J2000 coordinate system to a radar array measurement coordinate system according to the present invention;

[0032] Figure 3 A geometric relationship model diagram of the spaceborne radar and the aerial target in the present invention;

[0033] Figure 4 It is the 2D real trajectory diagram of the spaceborne detection radar tracking the aerial target in STK;

[0034] Figure 5 This is an enlarged view of the 2D real trajectory of the spaceborne detection radar tracking the aerial target in STK;

[0035] Figure 6 It is the 3D trajectory diagram of the aerial target in STK;

[0036] Figure 7 RMSE line graph for pitch angle estimation of aerial targets at different altitudes. DETAILED DESCRIPTION

[0037] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0038] Satellite-borne radar target tracking uses a nonlinear filtering algorithm to achieve high-precision aerial target tracking based on the motion model of aerial targets and radar measurements. There are two main errors when satellite-borne radar observes aerial targets: measurement error and positioning error of the detection platform itself. Both errors affect aerial target tracking. For measurement error, the satellite-borne radar has high measurement accuracy for radial distance, azimuth and Doppler frequency of aerial targets, and only the error of pitch angle is large. Generally, the output of pitch angle measurement is the pitch angle of the beam center. The large error of pitch angle makes it very difficult to track and locate aerial targets. For the positioning error of the detection platform itself, the current positioning error is generally around 10m on a given orbit.

[0039] In order to solve the problem of excessive error in pitch angle measurement, the height of the aerial target is generally estimated first. This can be done by using measurements from multiple satellite-borne radars, micro-multipath measurements from satellite-borne radars, or other methods. Then, the radial distance and azimuth of the aerial target are used by the satellite-borne radar to estimate the pitch angle through geometric methods to reduce tracking errors. However, when the satellite-borne radar is performing detection tasks, the attitude needs to be changed to adapt to the field of view requirements, or yaw guidance is required to make the Doppler center frequency 0, which makes the three attitude angles of the satellite-borne radar body coordinate system relative to the orbital coordinate system non-zero. The traditional method of estimating the pitch angle of aerial targets using geometry usually only considers the roll angle of the satellite-borne radar, which cannot be applied to the pitch angle estimation of detected aerial targets under more complex attitude changes.

[0040] Among them, the estimation method using micro-multipath measurement of satellite-borne radar is as follows: obtaining the signal transmission path when the satellite-borne radar illuminates the aerial target; the signal transmission path includes the transmission path, reflection path and scattering path obtained under the micro-multipath phenomenon; extracting the key point information in the signal transmission path; and using the key point information to solve the height of the aerial target.

[0041] The present invention utilizes the geometric relationship between the target and the radar, combines the radar's own posture at the same time and the radial distance and azimuth measurement of the aerial target with a known estimated altitude, and derives the equation of the pitch angle of the spaceborne radar with respect to the aerial target for solution.

[0042] The spaceborne radar can broadcast the position and attitude in the ECEF coordinate system or J2000 system at intervals of 1 second, and the interpolation and prediction accuracy of the attitude in a short time is very high. Therefore, the pitch angle of the aerial target can be estimated by using the attitude information of the spaceborne radar, the radial distance of the spaceborne radar to the aerial target, the azimuth angle and the estimated altitude of the aerial target. However, there is no research in the prior art on estimating the pitch angle of the aerial target using the attitude of the spaceborne radar.

[0043] The coordinate system measurement conversion process involved in the embodiment of the present invention is as follows:

[0044] ECEF coordinate system or J2000 coordinate system to array measurement coordinate system.

[0045] The steps to transfer the air target from the ECEF coordinate system or the J2000 coordinate system to the radar array measurement coordinate system are as follows: Figure 2 shown.

[0046] Given the positions of the satellite and the aerial target under ECEF / J2000 and the satellite's attitude quaternion under ECEF / J2000 (q 0 ,q 1 ,q 2 ,q 3 ), where q 0 is a scalar, q 1 ,q 2 ,q 3 is a vector. First, we can get the positions of satellite S and aerial target P in the ECEF / J2000 coordinate system as follows: and Then the position of the aerial target relative to the satellite coordinate system is It is expressed as:

[0047]

[0048] Represents the transformation matrix that transforms points in the ECEF / J2000 coordinate system to the body coordinate system of the spaceborne radar.

[0049] Assuming that the antenna rectangular coordinate system rotates γ degrees clockwise around the x-axis of the satellite body coordinate system, the position of the aerial target in the antenna coordinate system is It is expressed as:

[0050]

[0051] According to the previous definition of the array measurement coordinate system, the transformation of the aerial target from the antenna coordinate system to the array measurement coordinate system is expressed as:

[0052]

[0053] Among them, (R, Az, E) are radial distance, azimuth and elevation angle respectively.

[0054] A method for estimating the pitch angle of aerial targets using spaceborne radar based on satellite posture, such as Figure 1 As shown, the following steps are included:

[0055] S110, selecting the position of the satellite-borne radar, the position of the aerial target, the projection point of the aerial target on the ground and the position of the center of the earth as reference points, and constructing a geometric relationship model between the satellite-borne radar and the aerial target.

[0056] Specifically:

[0057] like Figure 3 As shown in the figure, point O represents the center of the earth, point S represents the position of the satellite-borne radar, point T represents the position of the aerial target, point G is the projection of the aerial target on the ground, and θ represents the downward angle of view from the satellite-borne radar to the aerial target. |ST| represents the radial distance measurement obtained by the satellite-borne radar directly irradiating the aerial target, and |OS| represents the distance from the satellite-borne radar to the center of the earth.

[0058] The reference points and related distances selected by the present invention are easier to measure, making the results obtained more accurate.

[0059] S120, based on the geometric relationship model, obtaining a first parameter set and a second parameter set; the first parameter set includes the distance from the satellite-borne radar to the center of the earth, the radial distance from the satellite-borne radar to the aerial target, the height of the aerial target and the distance from the projection point to the center of the earth; the second parameter set includes the position of the satellite-borne radar in any celestial body coordinate system, the attitude of the satellite-borne radar in any celestial body coordinate system and the position of the aerial target in any celestial body coordinate system; converting the position of the aerial target in any celestial body coordinate system into the position of the aerial target in the radar array measurement coordinate system;

[0060] Any celestial body coordinate system in the present invention may be an ECEF coordinate system or a J2000 coordinate system.

[0061] The ECEF coordinate system is consistent with the geophysical model and can closely fit the actual physical shape of the earth. It approximates the earth as a rotating ellipsoid, making calculations more accurate. It also supports coordinate transformation. The ECEF coordinate system can be easily converted to other earth coordinate systems. It is simpler in mathematical operations and is convenient for various geometric and physical calculations.

[0062] The J2000 coordinate system has high accuracy and stability, and has a clear conversion relationship with other commonly used coordinate systems. It can easily perform coordinate conversion to meet different observation and research needs. It is widely used in fields such as astronomical measurement. It is more convenient to convert when calculating the orbits and positions of celestial bodies in different coordinate systems.

[0063] Specifically:

[0064] |OS| is the distance from the satellite radar to the center of the earth, which is known, that is, the semi-major axis of the satellite radar; |ST| is the radial distance from the satellite radar to the aerial target, which is known; |GT| is the height of the aerial target, and the estimated value is known; the area detected by the satellite detection radar is generally known, so the approximate value of the distance from the projection point to the center of the earth |OG| can be obtained (obtained from the latitude of the center of the detection area). The approximate value calculation formula of |OG| is:

[0065]

[0066] Among them, a=6378.137 is the equatorial radius of the earth, b=6356.752 is the polar radius of the earth, and φ is the latitude of the center of the detection area.

[0067] Since the radar can only obtain the information of the aerial target in the array measurement coordinate system, that is, radial distance, azimuth, pitch angle, Doppler frequency, etc., but the actual description of the aerial target position information is in the ECEF, J2000 and other coordinate systems, it is necessary to transfer the aerial target measurement to the ECEF, J2000 and other coordinate systems for filtering. That is, the parameters of the ECEF, J2000 and other coordinate systems are used to represent the position of the target in the array measurement coordinate system.

[0068] The position of the air target in the ECEF coordinate system or the J2000 coordinate system is converted into the position of the air target in the radar array measurement coordinate system, including the following steps:

[0069] The position of the aerial target in the body coordinate system is calculated according to the position of the spaceborne radar in the ECEF coordinate system or the J2000 coordinate system, the position of the aerial target in the ECEF coordinate system or the J2000 coordinate system, and the attitude quaternion of the spaceborne radar in the ECEF coordinate system or the J2000 coordinate system;

[0070] The position of the aerial target in the antenna coordinate system is calculated based on the position of the aerial target in the body coordinate system and the position of the antenna center in the body coordinate system; the antenna center is the satellite's body coordinate system, and its origin is the satellite's center of mass.

[0071] Convert the position of the aerial target in the antenna coordinate system into the position in the radar array measurement coordinate system.

[0072] Specifically:

[0073] vector is the negative vector of the position vector of the spaceborne radar in the ECEF coordinate system or the J2000 coordinate system, which is a known quantity; vector It is the vector obtained by subtracting the position vector of the satellite-borne radar from the position vector of the aerial target in the ECEF coordinate system or the J2000 coordinate system. It is an unknown quantity.

[0074] According to the conversion process from ECEF coordinate system or J2000 coordinate system to array measurement coordinate system, vector It can be expressed by measuring (R, Az, E):

[0075]

[0076] In the formula, It represents the transformation matrix that transforms the points in the spaceborne radar body coordinate system to the rectangular coordinate system of the antenna array surface. It can be calculated by the installation angle of the antenna coordinate system relative to the body coordinate system and is a known quantity. The transformation matrix that converts the points in the ECEF / J2000 coordinate system to the body coordinate system of the spaceborne radar can be calculated from the attitude quaternion of the spaceborne radar under ECEF / J2000 and is a known quantity; the position of the aerial target in the antenna coordinate system is It can be expressed as (R, Az, E):

[0077]

[0078] The coordinate system conversion process is a necessary conversion process for satellite-borne radar target tracking. It is necessary to convert the target from the ECEF / J2000 coordinate system to the array measurement coordinate system. The present invention uses position and attitude to convert the coordinate system for the first time. Compared with the conversion using the six orbital elements, the present invention simplifies the conversion process and does not need to consider factors such as the precession and nutation of the earth, and has higher accuracy.

[0079] S130, constructing a first expression of the lower viewing angle according to the first parameter set, and constructing a second expression of the lower viewing angle according to the second parameter set.

[0080] According to the geometric relationship, the first expression of the lower viewing angle (the radian value of the lower viewing angle θ) is expressed as:

[0081]

[0082] The second expression for the lower viewing angle is:

[0083]

[0084] In the process of estimating the pitch angle by the traditional geometric method, only the first expression of the lower viewing angle is used to calculate the pitch angle, and it is only assumed that the satellite makes a roll angle deflection in attitude, which is a single case. However, in practice, due to yaw guidance or other factors, if the satellite also makes pitch angle deflection and yaw angle deflection, the traditional method cannot meet the work needs. The present invention introduces the second expression of the lower viewing angle, using the negative vector of the position vector of the satellite-borne radar in the ECEF coordinate system or the J2000 coordinate system The vector obtained by subtracting the position vector of the spaceborne radar from the position vector of the air target in the ECEF coordinate system or the J2000 coordinate system The relationship between it and the downward viewing angle is constructed, and the influence of the position and posture of the spaceborne radar on the pitch angle is taken into account, so that no matter what kind of attitude transformation the spaceborne radar makes, it can be represented by attitude quaternion.

[0085] The present invention is the first to use attitude quaternion for coordinate system conversion and filtering on a satellite-borne radar. Using attitude quaternion filtering conversion makes the conversion process simpler, so the present invention uses two expressions to jointly solve the pitch angle.

[0086] Compared with the previous method of estimating the pitch angle using only the first expression of the lower viewing angle, the present invention can cope with all the working attitudes of the satellite (i.e., the body coordinate system is transformed more complexly relative to the orbital coordinate system, and the traditional method of using the first expression of the lower viewing angle generally only assumes that the satellite performs a roll angle deflection), and can also be applied to the target pitch angle estimation of all satellite-borne radars that can provide satellite postures, and has a wide range of applications. At the same time, the known quantities in the two expressions have high measurement accuracy and small errors.

[0087] S140, solving the pitch angle by combining the first expression of the lower viewing angle and the second expression of the lower viewing angle.

[0088] Specifically:

[0089] In formula (9), R and Az are known variables, and E is an unknown variable. Combining formula (10) and formula (11) can obtain the equation group of the unknown variable E:

[0090]

[0091] Substituting formula (8) and formula (9) into formula (12) can obtain the unique solution of E, which is the value of the pitch angle.

[0092] Example 1

[0093] Assume that the orbital parameters of the spaceborne detection radar satellite are as shown in Table 1.

[0094] Table 1 Number of satellite orbits

[0095]

[0096]

[0097] The attitude angle of the radar body coordinate system relative to the orbital coordinate system is: rolling angle r c =75°, pitch angle Yaw angle φ c =5°. Assume that the latitude and longitude of the center of the detection area are 116.5°, 21.5° and 8km respectively, add 6 simulated aerial targets flying at a uniform speed and in a straight line, with altitudes of 6km, 7km, 8km, 9km, 10km and 11km respectively. Figure 4 , Figure 5 and Figure 6 As shown, Figure 4This is the 2D real trajectory diagram of the satellite-borne detection radar tracking the aerial target in STK. The purple arc is the projection of the satellite-borne radar orbit on the 2D plane, the purple fan-shaped part is the projection of the satellite-borne radar detection field of view on the 2D plane, the purple box part is the aerial target, and the orange line is the satellite-borne radar. Figure 5 This is an enlarged view of the 2D real trajectory of the spaceborne detection radar tracking the aerial target in STK. The purple box represents the box of the aerial target detected by the spaceborne radar. Figure 6 This is the 3D trajectory diagram of the aerial target in STK, where the yellow dots are the positions of the aerial targets at given simulation times, and the yellow lines are the 3D motion trajectories of the aerial targets.

[0098] Assume that the standard deviation of the one-fold measurement noise of the spaceborne radar is: radial distance 0.2km, azimuth angle 0.02°; the standard deviation of the three-fold measurement noise of the spaceborne radar is: radial distance 0.6km, azimuth angle 0.06°. The error of the position and attitude of the spaceborne radar is: the position positioning error is 10m in a single axis, and the attitude quaternion error is 1e-5. The one-fold error of the altitude estimation of the aerial target is 0.5km, and the three-fold error is 1.5km.

[0099] Since the latitude of the center of the detection area is 21.5°, the approximate value of |OG| calculated by formula (7) is 6375.3327km. In the simulation experiment, the pitch angle calculated by the radial distance and pitch true value, the satellite radar posture true value and the aerial target height true value was first simulated; then, when the satellite radar posture error was added, the pitch angle under one times the measurement noise, one times the height estimation error and three times the measurement noise, three times the height estimation error was solved respectively, and finally the root mean square error RMSE was compared. Figure 7 As shown, the RMSE of the pitch angle obtained under one times the measurement noise, one times the height estimation error and three times the measurement noise, three times the height estimation error is smaller than the measured true value, and the RMSE does not fluctuate with the height of the aerial target. Therefore, the present invention can effectively estimate the pitch angle of the aerial target when the posture changes.

Claims

1. A method for estimating the pitch angle of an aerial target using a spaceborne radar based on satellite posture, characterized in that: The following steps are involved: The position of the satellite-borne radar, the position of the aerial target, the projection point of the aerial target on the ground and the position of the center of the earth are selected as reference points to construct a geometric relationship model between the satellite-borne radar and the aerial target; Based on the geometric relationship model, a first parameter set and a second parameter set are obtained; the first parameter set includes the distance from the satellite-borne radar to the center of the earth, the radial distance from the satellite-borne radar to the aerial target, the height of the aerial target and the distance from the projection point to the center of the earth; the second parameter set includes the position of the satellite-borne radar in any celestial body coordinate system, the attitude of the satellite-borne radar in any celestial body coordinate system and the position of the aerial target in any celestial body coordinate system; the position of the aerial target in any celestial body coordinate system is converted into the position of the aerial target in the radar array measurement coordinate system; Constructing a first expression of the lower viewing angle according to the first parameter set, and constructing a second expression of the lower viewing angle according to the second parameter set; The first expression of the lower viewing angle and the second expression of the lower viewing angle are combined to solve the pitch angle.

2. The method for estimating the pitch angle of an aerial target using a spaceborne radar based on satellite posture according to claim 1, characterized in that: The conversion of the position of an aerial target in any celestial coordinate system into the position of the aerial target in the radar array measurement coordinate system includes: The position of the aerial target in the body coordinate system is calculated according to the position of the spaceborne radar in any celestial body coordinate system, the position of the aerial target in any celestial body coordinate system and the attitude quaternion of the spaceborne radar in any celestial body coordinate system; The position of the aerial target in the antenna coordinate system is calculated according to the position of the aerial target in the body coordinate system and the position of the antenna center in the body coordinate system; Convert the position of the aerial target in the antenna coordinate system into the position in the radar array measurement coordinate system.

3. The method for estimating the pitch angle of an aerial target using a spaceborne radar based on satellite posture according to claim 2, characterized in that: The first expression of the lower viewing angle is: Wherein, θ is the arc value of the lower viewing angle, S is the position of the satellite-borne radar, T is the position of the aerial target, G is the projection point of the aerial target on the ground, O is the position of the center of the earth, |OS| is the distance from the satellite-borne radar to the center of the earth, |ST| is the radial distance from the satellite-borne radar to the aerial target, |GT| is the height of the aerial target, and |OG| is the distance from the projection point to the center of the earth.

4. The method for estimating the pitch angle of an aerial target using a spaceborne radar based on satellite posture according to claim 3 is characterized in that: The second expression for the lower viewing angle is: In the formula, is the negative vector of the position vector of the spaceborne radar in any celestial body coordinate system, It is the vector obtained by subtracting the position vector of the satellite-borne radar from the position vector of the aerial target in any celestial coordinate system.

5. The method for estimating the pitch angle of an aerial target using a spaceborne radar based on satellite posture according to claim 1 or 4, characterized in that: The method for calculating the altitude of aerial targets includes using micro-multipath measurements of space-borne radar.

6. The method for estimating the pitch angle of an aerial target using a spaceborne radar based on satellite posture according to claim 5, characterized in that: Any coordinate system is the ECEF coordinate system.

7. The method for estimating the pitch angle of an aerial target using a spaceborne radar based on satellite posture according to claim 5, characterized in that: Any coordinate system is the J2000 coordinate system.

8. An electronic device, characterized in that: include: at least one processor; and, a memory communicatively coupled to at least one of the processors; Wherein, the memory stores instructions that can be executed by at least one of the processors, and the instructions are executed by at least one of the processors so that at least one of the processors can execute a method for estimating the pitch angle of aerial targets using a spaceborne radar based on satellite posture as described in any one of claims 1 to 7.

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