CN111504330B - Low-orbit spacecraft quasi-real-time orbit maneuver detection method based on measured data - Google Patents

Abstract

The invention discloses a low-orbit spacecraft quasi-real-time orbit maneuver detection method based on measured data, which aims at the characteristics of an in-orbit operation rule and actual measured data of a low-orbit spacecraft.

Description

Low-orbit spacecraft quasi-real-time orbit maneuver detection method based on measured data

Technical Field

The invention relates to the field of aerospace measurement and control, in particular to a low-orbit spacecraft quasi-real-time orbit maneuver detection method based on measured data.

Background

Since the first spacecraft of human beings in 10 months of 1957, the aerospace technology has been rapidly developed, and particularly after the 21 st century, the space activities of human beings have been rapidly increased, and the functions of the spacecraft have become increasingly complex. According to the statistics of space target data published by the U.S. officials, by 12 months in 2019, more than 2000 available spacecrafts currently operating in orbit are available, wherein the vast majority of the available spacecrafts operate at low orbit heights below 2000 kilometers, and more spacecrafts are continuously launched into the space in the future, such as the StarLink constellation plan of the company SPACEX in the united states, which plans to launch more than 10000 spacecrafts into the low orbit space.

The available spacecraft running on the low orbit is mainly applied to a plurality of fields such as meteorology, space environment monitoring, new technology verification, earth resource exploration, military reconnaissance, space early warning and the like. Due to the influence of different types of perturbation force such as earth non-spherical satellite gravitation, atmospheric resistance, sun-moon gravitation and the like or new application requirements, the low-orbit spacecraft often needs to adjust the current operation orbit of the low-orbit spacecraft so as to meet new task requirements of users or deal with emergency situations. For the management department of space targets, the orbital maneuver condition of the non-own spacecraft is unknown in advance, so that whether the orbital maneuver occurs or not needs to be detected from the observation data as fast as possible, and corresponding countermeasures need to be taken. If the low-orbit spacecraft has a track maneuvering behavior and the space target management party cannot detect and identify in time, the situations that iterative computation is difficult to converge and the subsequent tracking of the spacecraft is difficult exist in the track determination process, so that the cataloging management of the spacecraft is lost.

After the 21 st century, along with the rapid development of space technology, the competition of aerospace major countries including america in the space field is more and more intense, and the safety of the space field is more and more important in the whole national safety system, so that the orbital maneuver of the low-orbit spacecraft can be detected in a quasi-real-time manner, the cataloging management work of the non-own spacecraft is more important, and the method has great significance in guaranteeing the whole national space safety.

Currently, developing spacecraft orbit maneuver detection becomes a popular field for researchers, for example, a SACM method is proposed, which analyzes a variation range of a semi-major axis from data based on variation of the semi-major axis of a spacecraft orbit and further judges detection data by using a threshold; a comprehensive determination method based on the number of two lines has been proposed. However, most of the existing methods are based on the post analysis developed by cataloging orbit data, have no requirement on timeliness, and cannot meet the problem that orbit calculation and tracking observation have high requirement on timeliness of the orbited spacecraft.

In view of the reasons, the invention provides a low-orbit spacecraft quasi-real-time orbit maneuver detection method based on measured data aiming at the characteristics of the in-orbit operation rule and the actual measurement data of the low-orbit spacecraft, so that whether the low-orbit spacecraft has the track maneuver phenomenon in the in-orbit flying process can be detected in quasi-real time after the tracking of each arc section of the low-orbit spacecraft is finished, and the problems that iterative calculation is difficult to converge when the orbit maneuver exists in the low-orbit spacecraft orbit determination process and the spacecraft is difficult to track after the orbit is changed are effectively solved.

Disclosure of Invention

The invention aims to provide a low-orbit spacecraft quasi-real-time orbit maneuver detection method based on measured data, aiming at detecting whether a low-orbit spacecraft has a track maneuver phenomenon in an orbit flying process in quasi-real time and solving the problems that iterative calculation is difficult to converge when the low-orbit spacecraft has the track maneuver in a low-orbit spacecraft orbit determination process and the spacecraft is difficult to track after orbit change.

The invention realizes the purpose through the following technical scheme:

the method detects whether the low-orbit spacecraft has the phenomenon of track maneuver in the orbit flying process in quasi-real time according to the actually obtained observation data, and comprises the following steps:

the method comprises the following steps: the position coordinate of the known measuring device in the earth-fixed coordinate system is (x)_e,y_e,z_e) After the tracking observation of a certain arc section of the low-orbit spacecraft is finished, the measured values of the relative distance between a group of measuring equipment and the spacecraft can be obtained, and the group of measured values are expressed as (rho) in a horizontal coordinate system of the measuring station according to the time sequence_o1,ρ_o2,…,ρ_on) There are a total of n values;

step two: according to the latest TLE number obtained before the arc section tracking observation, the position coordinates of the spacecraft at the time corresponding to the n ranging values in the step one are obtained by calculation through an SGP4/SDP4 model, and the position coordinates of the group are expressed as (x) in a J2000 inertial coordinate system_oi,y_oi,z_oi) Wherein i is 1,2, …, n;

step three: n positions (x) obtained in the second step_oi,y_oi,z_oi) i-1, 2, …, n is converted to a position (x) in the earth-fixed coordinate system_i y_i z_i)^T＝M_T(x_oi y_oi z_oi)^TWherein M is_TIs J2000 inertial system to the earth-fixed coordinate systemThe transformation matrix of (2);

step four: according to the position coordinates of the measuring equipment in the step one and the position coordinates of the spacecraft in the step three, the theoretical distance value of the spacecraft relative to the measuring station can be calculated and recorded as (rho)_c1,ρ_c2,…,ρ_cn) I.e. by

Wherein i is 1,2, …, n;

step five: according to the actual distance value (rho) obtained by observation in the step one_o1,ρ_o2,…,ρ_on) And the theoretical distance value (p) calculated in step four_c1,ρ_c2,…,ρ_cn) Calculating the difference between them, i.e. Δ ρ_i＝ρ_oi-ρ_ciWherein i is 1,2, …, n;

step six: according to the delta rho calculated in the step five_i(i ═ 1,2, …, n), and residual ρ is calculated_rmsI.e. by

Will calculate the obtained rho_rmsComparing with a rail maneuvering judgment threshold value, if rho_rmsJudging that the spacecraft has orbital maneuver if the spacecraft is more than or equal to 2000 meters; if ρ_rmsIf the distance is less than 2000 m, judging that the spacecraft does not have orbital maneuver.

The invention has the beneficial effects that:

the invention relates to a low-orbit spacecraft quasi-real-time orbit maneuver detection method based on measured data, which is compared with the prior art, the invention provides the low-orbit spacecraft quasi-real-time orbit maneuver detection method based on the measured data aiming at the characteristics of the in-orbit operation rule and the actual measured data of a low-orbit spacecraft.

Drawings

FIG. 1 shows theoretical range values of a tracking arc segment of spacecraft 43481 at 9, 14 and 2019;

FIG. 2 is a difference between a theoretical range and an actual range for a tracking arc of spacecraft 43481 on 9/14/2019;

FIG. 3 shows theoretical range values of a tracking arc segment of a 13-Riyagi astronaut 43481 in 9/2019;

fig. 4 shows the difference between the theoretical range and the actual range for a tracking arc segment of 13-day aerospace vehicle 43481 at 9/2019.

Detailed Description

The invention will be further described with reference to the accompanying drawings in which:

the method detects whether the low-orbit spacecraft has the phenomenon of track maneuver in the orbit flying process in quasi-real time according to the actually obtained observation data, and comprises the following steps:

the method comprises the following steps: the position coordinate of the known measuring device in the earth-fixed coordinate system is (x)_e,y_e,z_e) After the tracking observation of a certain arc section of the low-orbit spacecraft is finished, the measured values of the relative distance between a group of measuring equipment and the spacecraft can be obtained, and the group of measured values are expressed as (rho) in a horizontal coordinate system of the measuring station according to the time sequence_o1,ρ_o2,…,ρ_on) There are a total of n values;

step two: according to the latest TLE number obtained before the arc section tracking observation, the position coordinates of the spacecraft at the time corresponding to the n ranging values in the step one are obtained by calculation through an SGP4/SDP4 model, and the position coordinates of the group are expressed as (x) in a J2000 inertial coordinate system_oi,y_oi,z_oi) Wherein i is 1,2, …, n;

step three: n positions (x) obtained in the second step_oi,y_oi,z_oi) i-1, 2, …, n is converted to a position (x) in the earth-fixed coordinate system_i y_i z_i)^T＝M_T(x_oi y_oi z_oi)^TWherein M is_TA transformation matrix from a J2000 inertial system to a ground-fixed coordinate system;

step four: according to the position coordinates of the measuring equipment in the step one and the position of the spacecraft in the step threeAnd (4) calculating the theoretical distance value of the spacecraft relative to the measuring station by setting the coordinate, and recording as (rho)_c1,ρ_c2,…,ρ_cn) I.e. by

Wherein i is 1,2, …, n;

step five: according to the actual distance value (rho) obtained by observation in the step one_o1,ρ_o2,…,ρ_on) And the theoretical distance value (p) calculated in step four_c1,ρ_c2,…,ρ_cn) Calculating the difference between them, i.e. Δ ρ_i＝ρ_oi-ρ_ciWherein i is 1,2, …, n;

step six: according to the delta rho calculated in the step five_i(i ═ 1,2, …, n), and residual ρ is calculated_rmsI.e. by

Will calculate the obtained rho_rmsComparing with a rail maneuvering judgment threshold value, if rho_rmsJudging that the spacecraft has orbital maneuver if the spacecraft is more than or equal to 2000 meters; if ρ_rmsIf the distance is less than 2000 m, judging that the spacecraft does not have orbital maneuver.

The first embodiment is as follows:

detection example for near-earth spacecraft orbital transfer

A spacecraft with the number of 43481 is selected from TLE data published in the United states as an analysis object, is an Iridium 110 emitted by Iridium company in the United states in 2018, 5 months and 22 days, and belongs to one satellite in the second generation Iridium constellation of the Iridium company. The number of TLEs published in 2019, 9, 13 and the method of the invention is adopted to calculate the theoretical distance value of the spacecraft relative to a certain measuring device in 2019, 9, 14 and 6 as shown in figure 1:

by adopting the method of the invention, the difference between the theoretical distance calculation value of the tracking radian and the actual distance measurement value is calculated, as shown in figure 2:

by adopting the method, the square average of the difference between the theoretical range finding value and the actual range finding value of the arc segment is calculated to be 2573.68 meters and is more than 2000 meters of the orbital transfer detection threshold value, so that the spacecraft is judged to have orbital maneuver at the moment.

Example two:

detection example for non-orbital transfer of near-earth spacecraft

The number of TLEs published in 2019, 9 and 13 of the spacecraft with the number of 43481 is also selected, and the theoretical distance value of the TLE relative to a certain measuring device in 2019, 9, 13 and 19 is calculated by adopting the method disclosed by the invention and is shown in FIG. 3;

by adopting the method of the invention, the difference between the theoretical distance calculation value of the tracking radian and the actual distance measurement value is calculated, as shown in figure 4;

by adopting the method, the square average of the difference between the theoretical range finding value and the actual range finding value of the arc segment is calculated to be 86.22 meters and is less than the orbital transfer detection threshold value of 2000 meters, so that the spacecraft is judged not to have orbital maneuver at the moment.

Post hoc evaluation

After-the-fact analysis is carried out based on the number of TLEs published in 2019, month 13 and 2019, month 9 and month 14, the spacecraft has orbital transfer maneuver around 2019, month 9 and month 14, day 2, and the semi-major axis is lifted by about 100 meters. The results of this analysis show that: the method can accurately detect whether the spacecraft has orbital maneuver or not after the equipment tracking is finished.

The foregoing shows and describes the general principles and features of the present invention, together with the advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (1)

1. A low orbit spacecraft quasi real-time orbit maneuver detection method based on measured data is characterized in that: according to the actually obtained observation data, the method for detecting whether the low-orbit spacecraft has the phenomenon of track maneuver in the in-orbit flight process in quasi-real time comprises the following steps:

the method comprises the following steps: the position coordinate of the known measuring device in the earth-fixed coordinate system is (x)_e,y_e,z_e) After the tracking observation of a certain arc section of the low-orbit spacecraft is finished, the measured values of the relative distance between a group of measuring equipment and the spacecraft can be obtained, and the group of measured values are expressed as (rho) in a horizontal coordinate system of the measuring station according to the time sequence_o1,ρ_o2,…,ρ_on) There are a total of n values;

step two: according to the latest TLE number obtained before the arc section tracking observation, the position coordinates of the spacecraft at the time corresponding to the n ranging values in the step one are obtained by calculation through an SGP4/SDP4 model, and the position coordinates of the group are expressed as (x) in a J2000 inertial coordinate system_oi,y_oi,z_oi) Wherein i is 1,2, …, n;

step three: n positions (x) obtained in the second step_oi,y_oi,z_oi) i-1, 2, …, n is converted to a position (x) in the earth-fixed coordinate system_i y_i z_i)^T＝M_T(x_oi y_oi z_oi)^TWherein M is_TA transformation matrix from a J2000 inertial system to a ground-fixed coordinate system;

step four: according to the position coordinates of the measuring equipment in the step one and the position coordinates of the spacecraft in the step three, the theoretical distance value of the spacecraft relative to the measuring station can be calculated and recorded as (rho)_c1,ρ_c2,…,ρ_cn) I.e. by

Wherein i is 1,2, …, n;

step five: according to the actual distance value (rho) obtained by observation in the step one_o1,ρ_o2,…,ρ_on) And the theoretical distance value (p) calculated in step four_c1,ρ_c2,…,ρ_cn) Calculating the difference between them, i.e. Δ ρ_i＝ρ_oi-ρ_ciWherein i is 1,2, …, n;

step six: according to the delta rho calculated in the step five_i(i ═ 1,2, …, n), and residual ρ is calculated_rmsI.e. by

Will calculate the obtained rho_rmsComparing with a rail maneuvering judgment threshold value, if rho_rmsJudging that the spacecraft has orbital maneuver if the spacecraft is more than or equal to 2000 meters; if ρ_rmsIf the distance is less than 2000 m, judging that the spacecraft does not have orbital maneuver.

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