A method for quickly and accurately calculating a transit period of a space target

Abstract

The application discloses a kind of space target transit period fast high-precision calculation method, the fast calculation of this method to space target transit period, first obtain given time range, space target information and circular ground area information, secondly, using high-precision orbit prediction model and using the way of large step recursion, the orbit prediction data of target is calculated and substar position, then the transit state of target at each time is analyzed, and the position before and after the substar of target enters and exits ground area is determined, finally, the transit period of target is calculated in combination with linear interpolation principle.The method can use the orbit prediction data of space target obtained by large step recursion to quickly calculate the transit period of substar of target in circular ground area, and it is suitable for various space targets in orbit maintaining state.

Description

Technical Field

[0001] This invention belongs to the field of aerospace technology, specifically, it is a method for rapid and high-precision calculation of the transit time of space targets. Background Technology

[0002] For ground areas, target transit time calculation utilizes target orbit prediction data to calculate the time period during which the target's nadir point will pass through the ground area within a given time range (prediction period). Transit prediction and transit time calculation are widely used in aerospace tracking and control networks and ground station systems.

[0003] The existing traditional method for calculating the transit time of a satellite nadir point is to obtain the target orbit prediction by recursively calculating the target position, and then obtain the transit time information by determining whether the target nadir point is within the ground area at each time. This method has redundant calculation steps and is time-consuming. Summary of the Invention

[0004] The purpose of this invention is to propose a fast and high-precision method for calculating the transit time of a space target. This method can quickly calculate the transit time of the circular ground area of ​​the target's nadir point by using space target orbit prediction data obtained by recursion with a large step size. It is applicable to various space targets in orbital maintenance state.

[0005] The technical solution to achieve the purpose of this invention is as follows: a method for rapid and high-precision calculation of the transit period of a space target. For the rapid calculation of the transit period of a space target, firstly, a given time range, space target information, and circular ground area information are obtained. Secondly, a high-precision orbit prediction model is used and a large step size recursion method is adopted to calculate the target's orbit prediction data and nadir position. Then, the transit state of the target at each moment is analyzed, and the position of the target's nadir before and after entering and leaving the ground area is determined. Finally, the transit period of the target is calculated by combining the principle of linear interpolation.

[0006] The specific implementation steps are as follows:

[0007] Step (1): Obtain the given time range information, spatial target information, and circular ground area information;

[0008] Step (2): Based on the given time range, use a high-precision orbit prediction model and adopt a large step size recursive method to calculate the orbit prediction data of the space target, that is, the position information of the target in the geocentric rectangular coordinate system;

[0009] Step (3): Calculate the target sub-satellite point from the target orbit prediction data, analyze the target's transit status at each time, and determine the sampling point positions before and after the target sub-satellite point transits;

[0010] Step (4): Calculate the target transit time period by combining the principle of linear interpolation.

[0011] Compared with the prior art, the significant advantages of this invention are: (1) the target transit time can be quickly calculated using only the target orbit prediction data obtained by large step recursion; (2) the calculation results have high accuracy. Attached Figure Description

[0012] Figure 1 This is a flowchart of a method for rapid and high-precision calculation of the transit time of a space target according to the present invention.

[0013] Figure 2 This is a schematic diagram illustrating the calculation of the transit time of the sub-satellite point of a space target in a specific embodiment of the present invention. Detailed Implementation

[0014] The present invention will now be further described with reference to the accompanying drawings.

[0015] like Figure 1 As shown, this invention provides a fast and high-precision calculation method for the transit time of space targets, comprising the following steps:

[0016] Step (1): Obtain the given time range information, spatial target information, and circular ground area information, where the circular ground area information includes the latitude, longitude, and altitude coordinates of the area center point O and the area radius R;

[0017] Step (2): Calculate the target orbit prediction data; Based on the given time range, use a high-precision orbit prediction model and adopt a large step size recursive method to calculate the target's position information in the geocentric rectangular coordinate system, and obtain the target orbit prediction data. The target orbit prediction data is the target's position information in the geocentric rectangular coordinate system.

[0018] Step (3): Calculate the target sub-satellite point from the target orbit prediction data, analyze the target's transit status at each time, and determine the sampling point positions before and after the target sub-satellite point transits;

[0019] Step 3.1: Obtain the geocentric coordinate system position from the target orbit prediction data, transform and project it to the latitude, longitude, and altitude coordinate system to obtain the target nadir point P. When the distance of the nadir point from the center of the region is less than the radius of the region, the inequality is satisfied. At that time, it is considered that the target is in transit.

[0020] Step 3.2: Select the target star's nadir point P in chronological order. t Analyze the transit status of the target nadir point and determine the sampling point locations before and after the nadir point enters and exits the ground area. When two adjacent points P t With P t+1 When all are outside the ground area, if the relationship is satisfied... This indicates that the trajectory of the target sub-satellite point is at P.t With P t+1 For transit between them, select P. t With P t+1 This serves as the sampling point location before and after the target satellite's nadir point enters and exits the ground area; when there are several points P... t P t+1 ... P t+n If it is within the ground area, then select P. t-1 With P t+n+1 This serves as the sampling point location before and after the target satellite's nadir point enters or exits the ground area.

[0021] Step (4): Calculate the target transit time period by combining the principle of linear interpolation.

[0022] Step 4.1: Record P s P is the sampling position before the target sub-satellite point enters the ground region. e Let Q be the sampling position after the target sub-satellite point leaves the ground region. s and Q e These represent the positions of the actual target's nadir point entering and exiting the ground region, respectively, with the center point O of the ground region located at the vector... The projection point on is P r ,like Figure 2 As shown.

[0023] Based on vector and plane geometric relationships, calculate P s vector starting from and with Q s vector starting from This determines the position Q of the target's sub-satellite point entering the ground region. s ,vector and The calculation formula is as follows:

[0024]

[0025]

[0026] Step 4.2: Calculate Q e vector starting from This determines the position Q of the target's nadir point above the ground. e ,vector The calculation formula is as follows:

[0027]

[0028] Step 4.3: Using the principle of linear interpolation, based on the target nadir point from position P... s Arrival at location Q s and Q eCalculate the distance and the time it takes for the target's nadir point to enter and exit the ground region. Let the target's nadir point be located at P. s The corresponding time for the position is T. s If the recursive step size of the orbital prediction data is Δt, then the target sub-satellite point is at the entry position Q. s The moment T r for:

[0029]

[0030] The target star's sub-point is at the exit position Q. e The moment T e for:

[0031]

[0032] This calculation yields the transit time of the space target over the circular ground area.

[0033] Example

[0034] To demonstrate the effectiveness of the algorithm of this invention and fully showcase its ability to quickly calculate the transit time of a target, the following experiment was conducted:

[0035] (1) Initial conditions and parameter settings of the experiment

[0036] The simulation experiment takes a satellite target as an example. The given time range starts at the UNIX timestamp 1668441600 and lasts for 24 hours. Three ground areas and one satellite target are set. The specific experimental parameters are shown in Table 1 and Table 2.

[0037] Table 1 Experimental parameters for the circular ground area

[0038]

[0039] Table 2 Satellite Target Experimental Parameters

[0040]

[0041] (2) Analysis of experimental results

[0042] Table 3 shows the target transit information obtained using the traditional transit time calculation method with a simulation step size of 1 second, including target number, ground area number, entry time and exit time information, with a total calculation time of 56.449 seconds.

[0043] Table 3 shows the calculation results of the traditional method with a step size of 1 second.

[0044]

[0045] Table 4 shows the target transit information obtained using the traditional transit time calculation method with a simulation step size of 40 seconds. The total calculation time is 3.163 seconds. Compared to the calculation results of the traditional method with a step size of 1 second, it is faster but less accurate.

[0046] Table 4 shows the calculation results of the traditional method with a step size of 40 seconds.

[0047]

[0048] Table 5 shows the target transit information calculated using the method of this patent at a simulation step size of 40 seconds, with an overall calculation time of 2.721 seconds. Compared to the calculation results of the traditional method at a step size of 1 second, this method is faster and more accurate.

[0049] Table 5 shows the calculation results of the method of this patent with a step length of 40 seconds.

[0050]

[0051] In summary, this invention uses only space target orbit predictions obtained through recursion with a relatively large step size to quickly calculate the target transit time with high accuracy.

[0052] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for rapid and high-precision calculation of the transit period of a space target, characterized in that, The specific implementation steps are as follows: Step (1): Obtain the given time range information, spatial target information, and circular ground area information; Step (2): Based on the given time range, use a high-precision orbit prediction model and adopt a large step size recursive method to calculate the orbit prediction data of the space target, that is, the position information of the target in the geocentric rectangular coordinate system; Step (3): Calculate the target sub-satellite point from the target orbit prediction data, analyze the target's transit status at each time, and determine the sampling point positions before and after the target sub-satellite point transits; Step (4): Calculate the target transit time period by combining the principle of linear interpolation.

2. The method for rapid and high-precision calculation of the transit time of space targets according to claim 1, characterized in that: The information about the circular ground area in step (1) includes the latitude, longitude, and altitude coordinates of the center point O of the area and the radius R of the area.

3. The method for rapid and high-precision calculation of the transit time of a space target according to claim 1, characterized in that, The specific implementation method of step (3) is as follows: Step 3.1: Obtain the geocentric coordinate system position from the target orbit prediction data, transform and project it to the latitude, longitude, and altitude coordinate system to obtain the target nadir point P. When the distance of the nadir point from the center of the region is less than the radius of the region, the inequality is satisfied. At that time, it was assumed that the target was in transit. Step 3.2: Select the target star's nadir point P in chronological order. t Analyze the transit status of the target nadir point and determine the sampling point positions before and after the nadir point enters and exits the ground area; when two adjacent points P t With P t+1 When all are outside the ground area, if the relationship is satisfied... This indicates that the trajectory of the target sub-satellite point is at P. t With P t+1 For transit between them, select P. t With P t+1 The sampling points are used as the locations of the target satellite's nadir points before and after entering and exiting the ground area; when there are several points P t P t+1 ... P t+n If it is within the ground area, then select P. t-1 With P t+n+1 This serves as the sampling point location before and after the target satellite's nadir point enters or exits the ground area.

4. The method for rapid and high-precision calculation of the transit time of a space target according to claim 1, characterized in that, The specific implementation method of step (4) is as follows: Step 4.1: Record P s P is the sampling position before the target sub-satellite point enters the ground region. e Let Q be the sampling position after the target sub-satellite point leaves the ground region. s and Q e These represent the positions of the actual target's nadir point entering and exiting the ground region, respectively, with the center point O of the ground region located at the vector... The projection point on is P r ; Based on vector and plane geometric relationships, calculate P s vector starting from and with Q s vector starting from This determines the position Q of the target's sub-satellite point entering the ground region. s ,vector and The calculation formula is as follows: Step 4.2: Calculate Q e vector starting from This determines the position Q of the target's nadir point above the ground. e ,vector The calculation formula is as follows: Step 4.3: Using the principle of linear interpolation, based on the target nadir point from position P... s Arrival at location Q s and Q e The distance is used to calculate the time it takes for the target's nadir point to enter and exit the ground area; Let the target star's nadir point be at point P. s The corresponding time for the position is T. s If the recursive step size of the orbital prediction data is Δt, then the target sub-satellite point is at the entry position Q. s The moment T r for: The target star's sub-point is at the exit position Q e The moment T e for: This allows us to calculate the transit time of a space target over a circular ground area.

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