Method for measuring distance and speed of space-based radar optical composite space target

Abstract

The invention provides a space-based radar optical composite space target distance and speed measurement method, which comprises the following steps of: firstly, performing theoretical analysis on a quantitative mapping relation between target relative acceleration and jerk and relative distance and relative speed under a relative measurement coordinate system aiming at relative measurement of a space target; obtaining a quantitative mapping relation between relative jerk and relative acceleration of the target and relative distance and relative speed under a measurement coordinate system, then combining with guidance information of optical angle measurement to carry out dimension reduction on search parameters, and then carrying out long-time coherent accumulation; compared with a traditional search method, the method has the advantages that the dimension reduction of high-dimensional parameters is realized, the operand is greatly reduced, and the method is more suitable for space-based platform working conditions with limited computing power and can be directly applied to engineering.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar measurement, and particularly relates to a method for measuring the distance and velocity of a space target by combining space-based radar and optics. Background Technique

[0002] With the rapid development of space technology, the ability of humans to enter and utilize space is continuously increasing. Space-based radar uses satellites as observation platforms, which can detect space targets and complete tasks such as search, tracking, and positioning measurement.

[0003] To achieve precise in-orbit detection of satellites, constructing a relative measurement model based on the motion equation of the orbital target is a prerequisite for the design of the measurement algorithm. Kelecy et al. proposed in the article "Satellite Maneuver Detection using Two-Line Element Data" published in the 9th issue of the Advanced Maui Optical and Space Surveillance Technologies Conference in 2007 to segment the two-line elements (TLE) of the target satellite and perform polynomial fitting, and then recursively calculate the prediction difference to achieve the detection of space targets. However, due to the usually weak echo of space targets and the large relative motion dynamics, this method brings relatively large measurement errors. Jia Xu et al. proposed a parameter estimation method based on maximum likelihood estimation in the article "Radar Maneuvering Target Motion Estimation Based on Generalized Radon-Fourier Transform" published in IEEE Transactions on Signal Processing in December 2012. However, this method requires four-dimensional search for distance, velocity, acceleration, and jerk, and the computational complexity is extremely large.

[0004] In summary, the existing TLE-based detection methods are mostly lagging in time and have relatively large estimation errors. The existing detection methods for high-dynamic weak targets require multi-dimensional search for space targets, and the computational complexity is extremely large. Summary of the Invention

[0005] To solve the above problems, the present invention provides a method for measuring the distance and velocity of a space target by combining space-based radar and optics. The relative motion model of the target under optical guidance is deduced, and then under optical guidance, ranging and velocity measurement based on dimensionality reduction parameter search are performed, which greatly reduces the computational complexity.

[0006] A method for measuring the distance and velocity of space targets by an optical composite space-based radar includes the following steps: S1: Obtain the third-order generalized random Fourier transform expression of the coherent accumulation result of the target echo signal in discrete form according to the generalized random Fourier transform algorithm , where is the relative distance corresponding to the th search point within the set relative distance search range between the radar and the target, is the velocity corresponding to the th search point within the set velocity search range of the target; S2: Construct an objective function based on the maximum likelihood estimation method, and then solve the objective function to obtain the target distance measurement value and the velocity measurement value ; S3: Obtain the target acceleration and the jerk according to the target distance measurement value and the velocity measurement value :

[0007]

[0008] where is the prior value of the target velocity calculated from the target orbit parameters, represents the fast time.

[0009] Furthermore, the formula for the third-order generalized random Fourier transform expression is:

[0010] where , is the distance search range, is the minimum relative distance between the radar and the target, is the maximum relative distance between the radar and the target, and there is , where represents the distance search point index, is the distance search step; , is the velocity search range, is the minimum velocity of the target, is the maximum velocity of the target, and there is , where represents the velocity search point index, is the velocity search step;​ For the acceleration corresponding to the th search point within the set acceleration search range of the target, and where and there is , is the minimum acceleration of the target, is the maximum acceleration of the target, where represents the acceleration search point index, is the acceleration search step size; For the jerk corresponding to the th search point within the set jerk search range of the target, and where and there is , is the minimum jerk of the target, is the maximum jerk of the target, where represents the jerk search point index, is the jerk search step size; is the pulse period, represents the period sequence number of the target echo signal, represents the total number of periods of the target echo signal, the range gate width , is the speed of light, is the range sampling rate, is the rounding function, is the phase compensation function for realizing pulse coherent integration.

[0011] Furthermore, the calculation formula of the phase compensation function is as follows:

[0012] where represents a complex number, represents the wavelength of the target echo signal.

[0013] Furthermore, for the relative distance minimum value , the radial velocity search range of the target is:

[0014] where is the lower limit of the radial velocity search at the relative distance minimum value , is the upper limit of the radial velocity search at the relative distance minimum value , , , are all set coefficients, and , , , where and are two orthogonal unit vectors within the intersecting cross-section circle of the radar equidistant stepped projection sphere and the target position error sphere, represents the center coordinates of the intersecting cross-section circle, is the parameter in polar coordinates where the intersecting cross-section circle lies, is the polar axis, is the polar angle; is the position coordinates of the radar in the geocentric coordinate system, is the relative velocity between the radar and the target in the observation coordinate system established with the radar as the center; For the maximum relative distance , the search range of the radial velocity of the target is:

[0015] where is the lower limit of the radial velocity search at the maximum relative distance , and is the upper limit of the radial velocity search at the maximum relative distance .

[0016] Furthermore, for the minimum relative distance , the search range of the tangential velocity of the target is:

[0017] where is the lower limit of the tangential velocity search at the minimum relative distance , and is the upper limit of the tangential velocity search at the minimum relative distance , and is the relative velocity between the radar and the target in the observation coordinate system established with the radar as the center; For the maximum relative distance , the search range of the tangential velocity of the target is:

[0018] where is the lower limit of the tangential velocity search at the maximum relative distance , and is the upper limit of the tangential velocity search at the maximum relative distance .

[0019] Furthermore, for the minimum relative distance , the search range of the radial acceleration of the target is:

[0020] Among them, is the lower limit of the radial acceleration search under the minimum relative distance ; is the upper limit of the radial acceleration search under the minimum relative distance ; is the current relative distance between the radar and the target; For the maximum relative distance , the radial acceleration search range of the target is:

[0021] Among them, is the lower limit of the radial acceleration search under the maximum relative distance ; is the upper limit of the radial acceleration search under the maximum relative distance .

[0022] Furthermore, the target radial acceleration under different relative distances is expressed as:

[0023] Among them, is the current relative velocity between the radar and the target in the observation coordinate system established with the radar as the center, is the current radial velocity of the target in the observation coordinate system established with the radar as the center, is the current relative distance between the radar and the target.

[0024] Furthermore, the target jerk under different relative distances is expressed as:

[0025] Among them, is the relative acceleration between the radar and the target at the current relative velocity ; is the target radial acceleration at the current relative distance ; is the current relative velocity between the radar and the target in the observation coordinate system established with the radar as the center, is the current relative distance between the radar and the target.

[0026] Beneficial effects: The present invention provides a method for measuring the distance and speed of space targets by using a space-based radar optical composite. Firstly, for relative measurement of space targets, a theoretical analysis is performed based on the quantitative mapping relationship between the target relative acceleration, the jerk and the relative distance and the relative speed in a relative measurement coordinate system to obtain the quantitative mapping relationship between the target relative jerk, the relative acceleration and the relative distance and the relative speed in the measurement coordinate system. Then, the dimension of search parameters is reduced in combination with the guidance information of optical angle measurement, and long-term coherent accumulation is performed. Compared with traditional search methods, the present invention realizes the dimension reduction of high-dimensional parameters, greatly reduces the amount of calculation, is more adaptable to the working conditions of space-based platforms with limited computing power, and can be directly applied in engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flow chart of a method for measuring distance and speed of space targets by a space-based radar optical composite space target provided by the present invention; Figure 2 A relative measurement coordinate system provided by the present invention; Figure 3 A schematic diagram of radar search and distance error provided by the present invention; Figure 4 A flowchart of the theoretical analysis of the quantitative mapping relationship provided by the present invention; Figure 5 A schematic diagram of the acceleration changing with distance provided by the present invention; Figure 6 This is a schematic diagram of the change of acceleration with distance provided by the present invention. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0029] The present invention proposes a multi-dimensional motion parameter constraint model for relative measurement of non-planar orbit targets by space-based radar. By using this model, the search interval can be reduced in dimension when multi-dimensional search is performed on the relative distance, velocity, acceleration and jerk of the target under the guidance of orbital parameters, thereby reducing the amount of calculation and ensuring that the measurement algorithm based on this model is implemented on a platform with strong resource constraints.

[0030] Specifically, Figure 1 As shown, a method for measuring distance and speed of space target by space-based radar optical composite includes the following steps: S1: According to the generalized random Fourier transform algorithm, the coherent accumulation result of the target echo signal is obtained in the discrete form of the third-order generalized random Fourier transform expression ,in, The first The relative distance corresponding to a search point is the th search point within the set speed search range of the target S2: Use the maximum likelihood estimation method to construct an objective function based on , and then solve the objective function to obtain the target distance measurement value and the speed measurement value ; S3: Obtain the target acceleration and the jerk according to the target distance measurement value and the speed measurement value :

[0031]

[0032] where is the prior value of the target speed calculated from the target orbit parameters, represents the fast time

[0033] The following details the recursive relationships between the target distance, speed, acceleration, and jerk to prove that the present invention can calculate the speed, acceleration, and jerk through the target distance

[0034] Step 1: Analyze the error range of the target motion parameters In actual detection, the orbit parameters of a space target are usually obtained by means such as ground measurement, and then the prior information of the target relative to the radar is obtained. However, there are usually errors in the orbit parameters, which also results in the prior position of the target being usually an error sphere. To analyze the error range of the target motion parameters, it is necessary to describe the relative motion state between the high-dynamic target in space and the radar. First, an observation coordinate system needs to be established with the observation radar as the center, as Figure 2 shown, where is the radial velocity of the target, is the tangential velocity of the target, represents the relative velocity, represents the relative distance. With the help of the high-precision target angle information obtained by optical sensing, the direction vector from the radar to the target can be obtained. Let this direction be the radial direction. Project onto the radial and tangential directions respectively to obtain the radial velocity and the tangential velocity , where the expression for the radial velocity is (1) And there is the following relationship between the radial velocity and the tangential velocity ​ (2) The acceleration expression can be obtained as follows: (3) As Figure 3 shown, let the position coordinates of the radar in the geocentric coordinate system be , the relative velocity , the position of the target-radar connection line and the two-sphere cross-section be , then the radial velocity value is (the relative velocity projected onto the radial direction). Since the intersection cross-section of the radar equidistant stepped projection sphere and the target position error sphere is a circle, we may use polar coordinates to parameterize as (4) where and are two orthogonal unit vectors within the cross-section circle, represents the center coordinates of the cross-section circle, is the parameter in polar coordinates. Then the radial velocity can be expressed as (5) where .

[0035] It is not difficult to find that for the minimum distance , the search range of the radial velocity is: (6) For the maximum distance , there is a search range of the radial velocity: (7) According to the relationship between the tangential velocity and the radial velocity in (2), it can be seen that when the radial velocity is maximum, the tangential velocity is minimum; while when the radial velocity is minimum, the tangential velocity is maximum. The range of the tangential velocity can be obtained: (8) Then, based on Equation (3), the maximum and minimum values of the radial acceleration can be obtained, that is: (9) From this, it can be known that when searching for a target with a relative distance of , the search range of the radial acceleration is .

[0036] Step 2: Projection of the distance error sphere based on optical guidance Detecting a target using a space-based radar, the cross-section determined by the intersection of the equidistant stepped projection spherical surface of the radar and the error sphere of the target position orbital parameters is a circle. Under optical guidance, the angle measurement is extremely accurate. Therefore, we only need to consider a point on the cross-section where the two spheres intersect, that is, the intersection point of the line connecting the radar and the target position and this interface, as shown in Figure 3 as shown.

[0037] Step 3: Narrow the velocity error range based on optical guidance In practical applications, prior information on the relative distance and relative velocity between the two stars can be obtained through the known target star orbital parameters. In the space-based radar and optical composite scenario, the target angle is usually measured using platform optical sensing, and the distance and velocity are measured using the radar. Under optical guidance, we only need to consider a point on the cross-section determined by the intersection of the equidistant stepped projection spherical surface of the radar and the error sphere of the target position orbital parameters. That is, in Equation (4), the coordinates are only related to the radius of the equidistant stepped projection sphere of the radar.

[0038] In the expression of the radial velocity in Equation (5), is equivalent to That is, in polar coordinates, the parameter is , then there is (10) Also, , then it is not difficult to see that the search range of the velocity corresponds to the point coordinates, which is equivalent to the one-to-one correspondence between the velocity search range and the distance search range.

[0039] Step 4: Narrow the acceleration error range based on optical guidance It can be seen from Equation (3) that the target radial acceleration can be uniquely determined by the tangential velocity and the relative distance . The tangential velocity and the radial velocity satisfy the constraint relationship of Equation (2). Therefore, the acceleration at different search distances can be determined through the radial velocity. However, due to errors in the orbital parameters, the possible positions of the target star form an error sphere in space. With the help of high-precision space-based optical angle measurement information, the error range of the orbital parameter guidance can be corrected, and the corrected search area is only a line segment at this angle within the sphere. At the same time, the radial velocity of the target within this area is .

[0040] From this, the expression of the target radial acceleration at different search distances can be deduced as: (11) In the formula, is the magnitude of the relative velocity, is the unit vector in the direction where the target is located.

[0041] Therefore, under optical guidance, with the known relative distance , and the radial acceleration being a fixed value, there is no need to search for it.

[0042] Step 5: Analyze the jerk error range based on optical guidance Differentiating the radial acceleration yields the jerk expression as follows: (12) Expanding the above equation gives (13) And there is (14) Substituting Equation (14) into Equation (13), we get: (15) Also, because (16) Then, we can substitute Equations (15) and (16) into (12) to obtain the jerk expression as follows: (17) Where represents the differentiation of the relative velocity between the target star and our star, that is, the relative acceleration.

[0043] Assume there is a point determined by the acceleration . According to Equation (3), it can be known that at this point is also determined. According to the following velocity vector relationship: (18) It can also be known that is also determined. Substituting Equations (3) and (18) into Equation (17) gives the jerk expression: (19) Considering the first term in the above equation, it is not difficult to find that for the determined known velocity and the determined unknown relative acceleration , both are independent of the relative distance . Then, on the surface intercepted by the target prior position error sphere (as shown in ) on the sphere with a radius of Figure 3 , the corresponding to each point is equal. Therefore, according to Equation (19), each acceleration value corresponds to a unique jerk value, thus achieving search dimensionality reduction.

[0044] Therefore, under optical guidance conditions, high-precision target angle information can be obtained. When searching for a target with a relative distance of , both the radial acceleration and the radial jerk are fixed values, and there is no need to search for them.

[0045] Step 6: Perform maximum likelihood estimation according to the above-mentioned dimensionality reduction parameter method Assume that the transmitted signal in the nth period is , where is the slow time, is the pulse period, is the fast time, and the target echo signal can be modeled as: (20) In the formula, represents the echo signal amplitude (including the target reflection characteristics), represents the time delay (related to the target distance R), represents the noise (usually assumed to be additive white Gaussian noise) Perform coherent integration on the echo signal, and the coherent integration result is used as the likelihood function, which can be expressed as (21) In the formula, , is the speed of light, is the phase compensation function for realizing pulse coherent integration.

[0046] The estimated values of each parameter can be obtained according to the likelihood function. The specific process is as follows: (22) In the formula, are the estimated results of the initial radial distance, radial velocity, radial acceleration, and radial jerk. MLE provides a theoretical framework for parameter estimation through model matching.

[0047] According to the generalized RFT (GRFT) algorithm, the present invention can obtain the third-order GRFT expression in discrete form as: (23) Among them, , is the distance search range, is the minimum relative distance between the radar and the target, is the maximum relative distance between the radar and the target, and there is , where represents the distance search point index, is the distance search step size; , is the speed search range, is the minimum speed of the target, is the maximum speed of the target, and where represents the speed search point index, is the speed search step size; is the th acceleration corresponding to the search point within the set acceleration search range of the target, and and and , is the minimum acceleration of the target, is the maximum acceleration of the target, where represents the acceleration search point index, is the acceleration search step size; is the th jerk corresponding to the search point within the set jerk search range of the target, and and and , is the minimum jerk of the target, is the maximum jerk of the target, where represents the jerk search point index, is the jerk search step size; is the pulse period, represents the period sequence number of the target echo signal, represents the total number of periods of the target echo signal, the range gate width , is the speed of light, is the range sampling rate, is the rounding function, is the phase compensation function for realizing pulse coherent integration, .

[0048] When the range template is and the speed template is , since the acceleration and jerk at different search ranges have been given and there is no need to search for them, Equation (23) can be rewritten as: (24) It can be seen from Equation (24) that when the search range , speed , acceleration , jerk When matching with the target's true distance, speed, acceleration, and jerk respectively, the energies of all echo pulses can be aggregated, thereby achieving coherent accumulation and finally obtaining the target distance and speed parameters.

[0049] According to the MLE method, the measurement results of the target distance and speed can be obtained: (25) Then, according to Equation (11) and Equation (19), the measurement results of the target acceleration and jerk can be obtained (26) (27) Furthermore, as Figure 4 shown, the present invention proposes a space-based radar optical composite high-dynamic target distance and speed low-computing-power high-precision measurement method. This method realizes ranging and speed measurement under low-computing-power conditions through the target relative motion model under optical guidance and the parameter search algorithm of the present invention.

[0050] In this embodiment, our satellite approaches the target satellite at a distance of 50 km and measures the relative distance and speed parameters of the two satellites. Figure 3 It shows the search method of the space-based radar for the position of the target satellite under optical guidance conditions. The specific simulation parameters are as follows:

[0051] First, through orbit parameter guidance, the prior information of the relative distance between the two satellites is obtained as 50 km, with an error of 5 km. Then the possible positions of the target satellite form an error sphere in space with a center distance of 50 km from our satellite and a radius of 5 km. The high-precision angle information obtained by optical sensing is used to further correct the error range of the orbit parameter guidance error. Since the typical value of the space-based optical angle measurement error is 0.01°, the lateral positioning error at a distance of 50 km is only 8.7 m, and its influence can be ignored in this embodiment.

[0052] Using the dimensionality reduction parameter search method proposed in the present invention, by calculating the acceleration and jerk values at different search distances in real time, only two-dimensional searches of distance and speed are required to achieve high-precision parameter estimation at a low computing power cost. The acceleration parameter of the dimensionality reduction algorithm changes with distance as Figure 5 shown, and the jerk parameter changes as Figure 6 shown.

[0053] Using the parameters shown in the above table, calculate the computational complexity (the computational complexity is measured by the number of real number multiplications) of the traditional parameter search algorithm and the dimensionality reduction parameter search algorithm respectively, and obtain the following results.

[0054]

[0055] From the fact that the total amount of operations in the above table is reduced by 24,084 times, it can be concluded that the dimension reduction parameter search method proposed by the present invention can significantly reduce the amount of operations and can realize high-precision range-velocity parameter measurement in real time on a space-based platform with limited computing power.

[0056] In summary, the space-based radar optical composite space target range-velocity measurement method provided by the present invention is a space-based radar space target range-velocity low-computing-power high-precision measurement method with dimension reduction search of motion parameters under optical guidance. Compared with the traditional precise ranging and velocity measurement algorithm based on the four-dimensional parameter search of range, velocity, acceleration, and jerk, the present invention takes into account various constraints of the space-based platform (computing power constraint, power consumption limitation, storage resource limitation, etc.), and combines the accuracy of angle measurement by optical detection to design a set of dimension reduction parameter search method under optical guidance, which significantly reduces the amount of operations and is applicable to the high-precision low-computing-power measurement of the range and velocity of high-dynamic targets in the space-based radar optical composite scenario and can be directly applied in engineering.

[0057] Of course, the present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can certainly make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for measuring the range and velocity of space targets by an optical composite space-based radar, characterized in that, Including the following steps: S1: Obtain the third-order generalized random Fourier transform expression of the coherent integration result of the target echo signal in discrete form according to the generalized random Fourier transform algorithm , where is the relative distance corresponding to the -th search point within the set relative distance search range between the radar and the target, is the velocity corresponding to the -th search point within the set velocity search range of the target; S2: Construct an objective function based on the maximum likelihood estimation method , and then solve the objective function to obtain the target distance measurement value and the speed measurement value ; ​ S3: According to the target distance measurement value and the speed measurement value obtain the target acceleration and the jerk : Among them, is the prior value of the target speed calculated from the target orbit parameters, represents the fast time.

2. The space-based radar optical composite space target range and velocity measurement method according to claim 1, wherein, The expression of the third-order generalized random Fourier transform The formula is as follows: Wherein, , is the distance search range, is the minimum relative distance between the radar and the target, is the maximum relative distance between the radar and the target, and there is , where represents the distance search point index, is the distance search step; , is the velocity search range, is the minimum velocity of the target, is the maximum velocity of the target, and there is , where represents the velocity search point index, is the velocity search step; is the acceleration corresponding to the th search point within the set acceleration search range of the target, and , and there is , , is the minimum acceleration of the target, is the maximum acceleration of the target, where represents the acceleration search point index, is the acceleration search step; is the jerk corresponding to the th search point within the set jerk search range of the target, and , and there is , , is the minimum jerk of the target, is the maximum jerk of the target, where represents the jerk search point index, is the jerk search step; is the pulse period, represents the period serial number of the target echo signal, represents the total number of periods of the target echo signal, and the range gate width , is the speed of light, is the distance sampling rate, is the rounding function, is the phase compensation function for realizing pulse coherent integration.

3. The space-based radar optical composite space target range and velocity measurement method according to claim 2, characterized in that, Phase compensation function The calculation formula is as follows: Among them, represents a complex number, represents the wavelength of the target echo signal.

4. The space-based radar optical composite space target range and velocity measurement method according to claim 2, characterized in that, For the relative distance minimum value , the search range of the target's radial velocity is: Among them, is the lower limit of the radial velocity search under the minimum relative distance , is the upper limit of the radial velocity search under the minimum relative distance , , , are all set coefficients, and , , , among which, and are respectively two orthogonal unit vectors within the intersecting cross-section circle of the radar equidistant stepped projection sphere and the target position error sphere, represents the center coordinate of the intersecting cross-section circle, is the parameter in the polar coordinates where the intersecting cross-section circle is located, is the polar axis, is the polar angle; is the position coordinate of the radar in the geocentric coordinate system, is the relative velocity between the radar and the target in the observation coordinate system established with the radar as the center; For the maximum relative distance , the search range of the target's radial velocity is as follows: Among them, is the lower limit of the radial velocity search under the maximum relative distance , and is the upper limit of the radial velocity search under the maximum relative distance .

5. The space-based radar optical composite space target range and velocity measurement method according to claim 4, characterized in that, For the minimum relative distance , the search range of the tangential velocity of the target is as follows: Among them, is the lower limit of tangential velocity search under the minimum relative distance , and is the upper limit of tangential velocity search under the minimum relative distance , and is the relative velocity between the radar and the target in the observation coordinate system established with the radar as the center; For the maximum relative distance , the search range of the tangential velocity of the target is as follows: Among them, is the lower limit of tangential velocity search under the maximum relative distance , and is the upper limit of tangential velocity search under the maximum relative distance .

6. The space-based radar optical composite space target range and velocity measurement method according to claim 5, wherein, For the minimum relative distance , the search range of the target's radial acceleration is as follows: Among them, is the lower limit of the radial acceleration search under the minimum relative distance , is the upper limit of the radial acceleration search under the minimum relative distance , is the current relative distance between the radar and the target; For the maximum relative distance , the search range of the target's radial acceleration is as follows: Among them, is the lower limit of radial acceleration search under the maximum relative distance , and is the upper limit of radial acceleration search under the maximum relative distance .

7. The space-based radar optical composite space target range and velocity measurement method according to claim 2, characterized in that Target radial acceleration at different relative distances The expression is as follows: Among them, is the current relative velocity between the radar and the target in the observation coordinate system established with the radar as the center, is the current radial velocity of the target in the observation coordinate system established with the radar as the center, is the current relative distance between the radar and the target.

8. The space-based radar optical composite space target range and velocity measurement method according to claim 2, characterized in that Jerk of the target at different relative distances The expression is: Among them, is the relative acceleration between the radar and the target at the current relative speed , is the current relative distance and the radial acceleration of the target is the current relative speed between the radar and the target in the observation coordinate system established with the radar as the center is the current relative distance between the radar and the target

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