A method for measuring the distance of moving targets at a mobile station site

Abstract

This invention discloses a method for measuring the distance to a moving target from a mobile station. It defines a method for transmitting an uplink measurement signal to a space / air target at time T0 and receiving a downlink measurement signal forwarded by the target at time T3. The method obtains the straight-line distance between the two stations at times T0 and T3. It also obtains the pitch and azimuth angles of the space / air target at time T3, and obtains the rectangular coordinates of a first unit vector. Based on the attitude information, a first matrix is ​​obtained. Based on the station information at time T3, a transformation matrix is ​​obtained, and based on the first matrix and the first unit vector, a second unit vector is obtained. Using the station vector at time T0 as the starting point and the station vector at time T3 as the ending point, the cosine of the angle between the second unit vector and the station vector is obtained, combined with the second unit vector. Finally, the method obtains the radial distance of the station relative to the space / air target at time T3 to obtain a time correction amount, and corrects the real-time external measurement results. This invention enables the correction of real-time external measurement results.

Description

Technical Field

[0001] This invention relates to the field of space / air target measurement technology, specifically a method for measuring the distance of a moving target at a mobile station. Background Technology

[0002] The telemetry, tracking, and command (TT&C) system measures the distance to cooperative targets primarily by sending measurement signals to the targets. After receiving the measurement signals, the targets perform coherent or incoherent forwarding. Once the TT&C system receives the forwarded measurement signals from the targets, it compares them with the signals transmitted locally to obtain the signal transmission time difference, thereby measuring the two-way distance.

[0003] When the telemetry, tracking, and command (TT&C) system operates on the mobile platform, the platform's position is constantly changing during the time intervals between transmitting and receiving measurement signals. When the mobile platform's TT&C system receives a measurement signal relayed from a space / air target, the platform's location relative to its position when the uplink measurement signal was transmitted has already changed. Considering that the radial distance is the radial distance between the location of the space / air target when it relayed the uplink measurement signal and the location of the mobile platform's TT&C system when it receives the downlink measurement signal, it is necessary to correct the directly measured results based on the change in the mobile platform's location to obtain the accurate radial distance.

[0004] Existing technology, specifically invention patent CN115200573A, describes a method, system, and storage medium for positioning space target measurement equipment. This method acquires position measurement data of the space target relative to the measurement equipment; transforms this data from a first terrestrial coordinate system centered on the measurement equipment to a second terrestrial coordinate system centered on the Earth's center, obtaining first three-dimensional position data; transforms the first three-dimensional position data of the measurement equipment from the second terrestrial coordinate system to the Earth coordinate system, obtaining second three-dimensional position data; based on the precise ephemeris of the space target, obtains third three-dimensional position data of the space target in the Earth coordinate system at a preset observation time; and determines the position positioning data of the measurement equipment in the Earth coordinate system based on the second and third three-dimensional position data. Therefore, this invention provides a novel method for achieving high-precision positioning of space-based measurement equipment without relying on GNSS and geodesy. Existing technology, however, provides static positioning. Summary of the Invention

[0005] The technical problem to be solved by this invention is to correct the ranging results when the mobile platform telemetry and control system performs distance measurement on space / air targets, so as to obtain the true radial distance of the target from the mobile platform telemetry and control system.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A method for measuring the distance to a moving target at a mobile station site includes the following steps:

[0008] The mobile platform telemetry and control system is defined to send uplink measurement signals to space / air targets at time T0, and to receive downlink measurement signals forwarded by the targets at time T3;

[0009] Acquire the station location information and attitude information of the mobile platform telemetry and control system at times T0 and T3, perform coordinate transformation on the station location information and attitude information at these two times, and obtain the straight-line distance between the two stations after coordinate transformation;

[0010] At time T3, obtain the pitch and azimuth angles of the space / air target in the measurement coordinate system, obtain the rectangular coordinates of the first unit vector in the measurement coordinate system, and obtain the first matrix based on the attitude information of the maneuvering platform's telemetry and control system.

[0011] Based on the station location information of the mobile platform telemetry and control system at time T3, the transformation matrix of the mobile platform telemetry and control system for space / air targets is obtained; and based on the transformation matrix, the first matrix, and the first unit vector, the second unit vector is obtained.

[0012] Starting from the station address at time T0 and ending at the station address at time T3, obtain the station address vector and combine it with the second unit vector to obtain the cosine value of the angle between the second unit vector and the station address vector; and obtain the radial distance of the station address at time T3 relative to the space / air target.

[0013] Based on the radial distance to the target, a time correction amount is obtained, and the real-time external measurement results are corrected based on the time correction amount.

[0014] Advantages: The mobile platform measurement and control system corrects the two-way distance based on real-time station location information and attitude information to obtain the true radial distance, and calculates the accurate time when the corresponding downlink measurement signal is sent based on the true radial distance, thus obtaining accurate (time, station location, radial distance).

[0015] In one embodiment of the present invention, the straight-line distance between the two stations is obtained by the following formula:

[0016]

[0017] In the formula, L represents the straight-line distance between the two stations, (X0, Y0, Z0) represents the station information at time T0, which is obtained by coordinate transformation from the station's longitude, latitude, and altitude information; (X3, Y3, Z3) represents the station information at time T3, which is obtained by coordinate transformation from the station's longitude, latitude, and altitude information.

[0018] In one embodiment of the present invention, the rectangular coordinates of the first unit vector in the measurement coordinate system are obtained by the following formula:

[0019]

[0020] In the formula, The first unit vector is represented by its rectangular coordinates in the measurement coordinate system. cosEsinA, sinE, and cosEcosA are specific rectangular coordinate values. cos represents the cosine function, sin represents the sine function, E represents the pitch angle of the space / air target in the measurement coordinate system, and A represents the azimuth angle of the space / air target in the measurement coordinate system.

[0021] In one embodiment of the present invention, the first matrix is ​​obtained by the following formula:

[0022]

[0023] In the formula, C represents the first matrix. θ3 and γ3 represent the yaw angle, pitch angle, and roll angle of the attitude information of the maneuvering platform telemetry and control system at time T3, respectively.

[0024] In one embodiment of the present invention, the transformation matrix is ​​obtained by the following formula:

[0025]

[0026] In the formula, Q represents the transformation matrix, and Lon3 and Lat3 represent the station location information of the mobile platform telemetry and control system at time T3, namely, the longitude and latitude before coordinate transformation. The transformation matrix is...

[0027] In one embodiment of the present invention, the second unit vector is obtained by the following formula: In the formula, It is represented as the second vector.

[0028] In one embodiment of the present invention, the cosine value of the included angle is obtained by the following formula:

[0029]

[0030] In the formula, cosβ represents the cosine of the angle between the second unit vector and the station vector.

[0031] In one embodiment of the present invention, the radial distance of the station location relative to the space / air target at time T3 is obtained by the following formula:

[0032]

[0033] In the formula, B represents the radial distance.

[0034] In one embodiment of the present invention, the time correction amount is obtained by the following formula:

[0035]

[0036] In the formula, T' represents the time correction amount, and c represents the speed of light.

[0037] In one embodiment of the present invention, the modified external test result is (T3-T', Lon3, Lat3, H3, B).

[0038] Compared with the prior art, the beneficial effects of the present invention are: by introducing real-time station information and real-time attitude information of the mobile platform to dynamically correct the two-way distance measurement results, the accurate radial distance of the space / air target to the mobile platform measurement and control system can be obtained. Attached Figure Description

[0039] Figure 1 This is a flowchart of a method for measuring the distance to a moving target at a mobile station location, according to an embodiment of the present invention.

[0040] Figure 2 This is a schematic diagram showing the relative position of the mobile platform measurement and control system and the target in an embodiment of the present invention.

[0041] Figure 3 This is an approximate schematic diagram of the relative position between the moving platform measurement and control system and the target in an embodiment of the present invention. Detailed Implementation

[0042] To facilitate understanding of the technical solution of the present invention by those skilled in the art, the technical solution of the present invention will now be further described in conjunction with the accompanying drawings.

[0043] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0044] Please see Figures 1 to 3 As shown, this invention provides a method for measuring the distance to a moving target from a mobile station location. During the distance measurement process of a space / air target by a mobile platform telemetry and control system, the relative positions of the mobile platform telemetry and control system and the target are shown in Table 1 and... Figure 2 As shown.

[0045] Table 1. Relative positions of the mobile platform's telemetry and control system to space / air targets.

[0046] time Location of Measurement and Control System Target location Remark T0 O <![CDATA[S0]]> Uplink measurement signal sent T1 <![CDATA[P1]]> <![CDATA[S1]]> Uplink measurement signal arrives at target T2 <![CDATA[P2]]> <![CDATA[S2]]> Measurement signals are relayed through the target. T3 <![CDATA[P3]]> <![CDATA[S3]]> The measurement signal is forwarded to the measurement and control system.

[0047] The mobile platform telemetry and control system sends an uplink measurement signal to the space / air target at time T0. The space / air target receives the uplink measurement signal at time T1 and completes the generation and transmission of the downlink measurement signal at time T2. The mobile platform telemetry and control system receives the downlink measurement signal forwarded by the target at time T3.

[0048] The measurement signal is emitted by the mobile platform telemetry and control system at point O and received at position P3. Therefore, the radial distance measured by the mobile platform telemetry and control system can be expressed as (time, station location, radial distance): that is, (T2, P3, ... ),in The magnitude of the vector is its length.

[0049] Assume the length of OS2 is A', the length of P3S2 is B', the length of OS1 is C', the length of S1S2 is D, the length of OP3 is L', and ∠P3OS2 = β. Within the signal relay time τ0 = T2 - T1 for the space / air target pair, the distance the space / air target travels is much smaller than the radial distance between it and the maneuvering platform's telemetry and control system. Figure 2 S1 and S2 can be approximated as the same location, such as Figure 3 As shown.

[0050] The mobile platform telemetry and control system at position P3 calculates the two-way distance R by comparing the time difference between the transmission time of the uplink measurement signal and the reception time of the downlink measurement signal, where R = z0 + A' + B'. Here, z0 = τ0c is the distance value calculated based on the time difference between the transmission of the measurement signal by the space / air target, and c is the speed of light. z0 is generally obtained through pre-measurement and is a known value. Therefore, it is not considered in the following description, assuming that the two-way distance has already been deducted, i.e., R = A' + B'.

[0051] Based on the above principles, the method for measuring the distance to a moving target at a mobile station site includes the following steps:

[0052] S100 defines that the mobile platform telemetry and control system sends uplink measurement signals to the space / air target at time T0, and receives downlink measurement signals forwarded by the target at time T3.

[0053] S200: Obtain the station location information and attitude information of the mobile platform telemetry and control system at times T0 and T3, perform coordinate transformation on the station location information and attitude information at these two times respectively, and obtain the straight-line distance between the two stations after coordinate transformation.

[0054] Specifically, when the mobile platform telemetry and control system sends uplink measurement signals, the system's location is at point O. The system reads the station address information (longitude, latitude, altitude) output by the platform's built-in satellite inertial navigation system, i.e., (Lon0, Lat0, H0), and attitude information (yaw, pitch, roll), i.e., (…). θ0, γ0). After the measurement signal is relayed by the space / air target, when it reaches the mobile platform telemetry and control system, the mobile platform telemetry and control system is located at point P3. The mobile platform telemetry and control system reads the station location information and attitude information output by the platform's built-in satellite combined inertial navigation system, namely (Lon3, Lat3, H3) and ( θ3, γ3).

[0055] The station location information (Lon0, Lat0, H0) and (Lon3, Lat3, H3) in the WGS84 coordinate system are transformed to (X0, Y0, Z0) and (X3, Y3, Z3) in the ECEF coordinate system, respectively. The distance change between the two stations of the mobile platform telemetry and control system within the measurement signal transmission and reception interval is calculated, i.e., the straight-line distance between the two stations, using the following formula:

[0056]

[0057] In the formula, L represents the straight-line distance between the two stations, (X0, Y0, Z0) represents the station information at time T0, obtained by coordinate transformation from the station's longitude, latitude, and altitude information, and (X3, Y3, Z3) represents the station information at time T3, obtained by coordinate transformation from the station's longitude, latitude, and altitude information. The straight-line distance between the two stations is equivalent to the length of OP3.

[0058] S300: Obtain the pitch and azimuth angles of the space / air target in the measurement coordinate system at time T3, and obtain the rectangular coordinates of the first unit vector in the measurement coordinate system. Based on the attitude information from the maneuvering platform's telemetry and control system, obtain the first matrix.

[0059] The measurement coordinate system is the array coordinate system. At time T3, the maneuvering platform telemetry and control system tracks and measures the space / air target to obtain the target's pitch angle E and azimuth angle A in the measurement coordinate system.

[0060] The rectangular coordinates of the first unit vector in the measurement coordinate system are obtained using the following formula:

[0061]

[0062] In the formula, The first unit vector is represented by its rectangular coordinates in the measurement coordinate system. cosEsinA, sinE, and cosEcosA are specific rectangular coordinate values. cos represents the cosine function, sin represents the sine function, E represents the pitch angle of the space / air target in the measurement coordinate system, and A represents the azimuth angle of the space / air target in the measurement coordinate system.

[0063] The first matrix is ​​obtained using the following formula:

[0064]

[0065] In the formula, C represents the first matrix. θ3 and γ3 represent the yaw angle, pitch angle, and roll angle of the attitude information of the maneuvering platform telemetry and control system at time T3, respectively.

[0066] S400, based on the station location information of the mobile platform telemetry and control system at time T3, obtain the transformation matrix of the mobile platform telemetry and control system for space / air targets. And based on the transformation matrix, the first matrix, and the first unit vector, obtain the second unit vector.

[0067] The transformation matrix is ​​obtained using the following formula:

[0068]

[0069] In the formula, Q represents the transformation matrix, and Lon3 and Lat3 represent the station location information of the mobile platform telemetry and control system at time T3, namely the longitude and latitude before coordinate transformation. The transformation matrix Q is the coordinate transformation matrix from the northeast-northeast coordinate system to the geocentric-earth-fixed coordinate system, and the result of the transformation matrix Q is equivalent to the two-way distance R.

[0070] The second unit vector is obtained using the following formula: In the formula, It is represented as the second vector.

[0071] S500: Taking the station address at time T0 as the starting point and the station address at time T3 as the ending point, and combining it with the second unit vector, obtain the cosine value of the angle between the second unit vector and the station address vector; and obtain the radial distance of the station address at time T3 relative to the space / air target.

[0072] The cosine of the included angle is obtained using the following formula:

[0073]

[0074] In the formula, cosβ represents the cosine of the angle between the second unit vector and the station vector. This angle is equivalent to ∠P3OS2.

[0075] The radial distance between the station location and the space / air target at time T3 is obtained using the following formula:

[0076]

[0077] In the formula, B represents the radial distance. That is, the radial distance B is equivalent to the length of P3S2.

[0078] S600: Based on the target radial distance, obtain the time correction amount, and based on the time correction amount, correct the real-time external measurement results.

[0079] The time correction amount is obtained using the following formula:

[0080]

[0081] In the formula, T' represents the time correction amount, and c represents the speed of light.

[0082] The corrected external test results are (T3-T', Lon3, Lat3, H3, B).

[0083] Please see Figures 1 to 3 As shown, in one embodiment of the present invention, it is assumed that the satellite orbital altitude above the ground is h = 500 km, the Earth's radius is R0 = 6371 km, the satellite transponder distance to zero is z0 = 10 km, the satellite orbits the Earth once in time P = 1 h (3600 s), and the speed of light is c. The on-board relay time is:

[0084]

[0085] The length of the arc segment of the satellite's motion within the time period is:

[0086]

[0087] It is evident that during the time it takes for the measurement signal to be relayed on the satellite, the tangential distance of the satellite's motion is very small relative to the satellite-to-ground distance. Therefore Figure 2 It can be approximated as Figure 3 .

[0088] The mobile platform telemetry and control system reads satellite combined inertial navigation information upon transmitting uplink and receiving downlink measurement signals, respectively, to obtain the mobile platform's station location and attitude information at times T0 and T3 (Lon0, Lat0, H0, ...). θ0, γ0) and (Lon3, Lat3, H3, θ3, γ3). Through coordinate transformation, (X0, Y0, Z0) and (X3, Y3, Z3) can be obtained, and the straight-line distance L between the two stations can be calculated. Based on the target tracking measurement results of the mobile platform telemetry and control system, the two-way distance R obtained at time T3, and the angle measurement results are the pitch angle E and azimuth angle A, can be calculated. Thus, a vector is obtained. (Same direction as )and The cosine of the angle between them:

[0089] The satellite's on-board relay time τ0 can be pre-measured and calibrated, with the corresponding on-board distance zero value being z0 = τ0c. The measurement signal received by the mobile platform's telemetry and control system at station P3 is emitted by the satellite at position S2; therefore, the radial distance corresponding to P3 is:

[0090] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0091] The above embodiments are merely examples of implementation methods of the invention. The scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for measuring the distance to a moving target at a mobile station site, characterized in that, Includes the following steps: The mobile platform telemetry and control system is defined to send uplink measurement signals to space / air targets at time T0, and to receive downlink measurement signals forwarded by the targets at time T3; Acquire the station location information and attitude information of the mobile platform telemetry and control system at times T0 and T3, perform coordinate transformation on the station location information and attitude information at these two times, and obtain the straight-line distance between the two stations after coordinate transformation; At time T3, obtain the pitch and azimuth angles of the space / air target in the measurement coordinate system, obtain the rectangular coordinates of the first unit vector in the measurement coordinate system, and obtain the first matrix based on the attitude information of the maneuvering platform's telemetry and control system. Based on the station location information of the mobile platform telemetry and control system at time T3, obtain the conversion matrix of the mobile platform telemetry and control system for space / air targets; And based on the transformation matrix, the first matrix, and the first unit vector, the second unit vector is obtained; Starting from the station address at time T0 and ending at the station address at time T3, obtain the station address vector and combine it with the second unit vector to obtain the cosine value of the angle between the second unit vector and the station address vector; and obtain the radial distance of the station address at time T3 relative to the space / air target. Based on the radial distance to the target, a time correction amount is obtained, and the real-time external measurement results are corrected based on the time correction amount.

2. The method for measuring the distance to a moving target at a mobile station site according to claim 1, characterized in that, The straight-line distance between the two station sites is obtained by the following formula: In the formula, L represents the straight-line distance between the two stations, (X0, Y0, Z0) represents the station information at time T0, which is obtained by coordinate transformation from the station's longitude, latitude, and altitude information; (X3, Y3, Z3) represents the station information at time T3, which is obtained by coordinate transformation from the station's longitude, latitude, and altitude information.

3. The method for measuring the distance to a moving target at a mobile station site according to claim 2, characterized in that, The rectangular coordinates of the first unit vector in the measurement coordinate system are obtained using the following formula: In the formula, The first unit vector is represented by its rectangular coordinates in the measurement coordinate system. cosEsinA, sinE, and cosEcosA are specific rectangular coordinate values. cos represents the cosine function, sin represents the sine function, E represents the pitch angle of the space / air target in the measurement coordinate system, and A represents the azimuth angle of the space / air target in the measurement coordinate system.

4. The method for measuring the distance to a moving target at a mobile station site according to claim 3, characterized in that, The first matrix is ​​obtained using the following formula: In the formula, C represents the first matrix. θ3 and γ3 represent the yaw angle, pitch angle, and roll angle of the attitude information of the maneuvering platform telemetry and control system at time T3, respectively.

5. The method for measuring the distance to a moving target at a mobile station site according to claim 4, characterized in that, The transformation matrix is ​​obtained using the following formula: In the formula, Q represents the transformation matrix, and Lon3 and Lat3 represent the station information of the mobile platform telemetry and control system at time T3, namely the longitude and latitude before coordinate transformation.

6. The method for measuring the distance to a moving target at a mobile station site according to claim 5, characterized in that, The second unit vector is obtained using the following formula: In the formula, It is represented as the second vector.

7. The method for measuring the distance to a moving target at a mobile station site according to claim 6, characterized in that, The cosine value of the included angle is obtained by the following formula: In the formula, cosβ represents the cosine of the angle between the second unit vector and the station vector.

8. The method for measuring the distance to a moving target at a mobile station site according to claim 7, characterized in that, The radial distance between the station location and the space / air target at time T3 is obtained using the following formula: In the formula, B represents the radial distance; R represents the two-way distance obtained at time T3.

9. The method for measuring the distance to a moving target at a mobile station site according to claim 8, characterized in that, The time correction amount is obtained using the following formula: In the formula, T′ represents the time correction amount, and c represents the speed of light.

10. The method for measuring the distance to a moving target at a mobile station site according to claim 9, characterized in that, The revised external test results are (T3-T′, Lon3, Lat3, H3, B).

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