Big-ellipse frozen orbit based GNSS orbit determination extrapolation method

Abstract

The application discloses a GNSS-based extrapolation method for a large-ellipse frozen orbit, which comprises the following steps: step one: acquiring the position and speed of a navigation receiver orbit according to the effective state of navigation data; step two: calculating satellite orbit elements (distance and speed values, moment of momentum, semi-major axis, orbital angular velocity, eccentricity, orbital inclination, ascending node right ascension, latitude amplitude angle, and perigee amplitude angle) by using t GNSS moment of momentum, semi-major axis, orbital angular velocity, eccentricity, orbital inclination, ascending node right ascension, latitude amplitude angle, and perigee amplitude angle); step three: judging the effectiveness of navigation data according to the calculation results of the satellite orbit elements; step four: extrapolating and calculating the orbit parameter true anomaly and latitude amplitude angle at the current satellite time; and step five: calculating the instantaneous orbital angular velocity, thereby completing the GNSS-based orbit extrapolation design for a large-ellipse frozen orbit. The application only uses the orbiting information of the GNSS time to extrapolate the orbit elements of the satellite, thereby achieving satellite autonomous positioning and autonomous attitude control, reducing the positioning requirements of the satellite to the ground station, and improving the autonomous ability of the satellite.

Description

Technical Field

[0001] This invention relates to the field of satellite autonomous navigation technology, specifically to a GNSS-based orbit extrapolation method for highly elliptical frozen orbits. Background Technology

[0002] The development of aerospace technology demands that satellites be capable of autonomous orbit determination, on-orbit satellite acquisition and maintenance, and deep space exploration. Autonomous navigation is a key technology in these missions. Autonomous navigation refers to a satellite obtaining its absolute position and velocity independently, without the aid of ground-based systems, through onboard computers and measurement equipment. With the rapid development of my country's space technology, the number of high-orbit satellites is increasing rapidly, leading to a growing demand for autonomous positioning and attitude control. While GNSS-based orbit determination extrapolation methods for circular orbits are mature, extrapolation for highly elliptical frozen orbits is a first. Ground-based orbit determination cannot be guaranteed in real time, requiring multiple ground-based orbit measurements to determine the satellite's orbit and input the orbital parameters. This type of navigation relies heavily on ground-based orbit determination technology, which has the disadvantage of significant dependence on the ground. Achieving high-precision orbit prediction requires multiple ground stations and long-term observation. Autonomous navigation for highly elliptical frozen orbits using GNSS-based orbit determination extrapolation provides an effective way to provide satellite position information. Summary of the Invention

[0003] To address or partially address the problems existing in related technologies, this invention provides a GNSS-based orbit extrapolation method for highly elliptical frozen orbits, which can expand the application scope of autonomous navigation and enable it to effectively determine satellite orbit positions on more complex highly elliptical frozen orbits.

[0004] This invention provides a GNSS-based extrapolation method for determining the orbit of a highly elliptical frozen orbit, comprising:

[0005] Based on the validity status of the navigation data, obtain the position and speed of the navigation receiver for orbit determination;

[0006] Calculate satellite orbital elements using the position and velocity vectors at tGNSS time;

[0007] The validity of navigation data is determined based on the calculation results of various satellite orbit elements.

[0008] Extrapolate the orbital parameters, true anomaly angle and latitudinal argument, at the current satellite moment.

[0009] Calculate the instantaneous orbital angular velocity and complete the GNSS-based orbit extrapolation design of the large elliptical frozen orbit.

[0010] Optionally, obtaining the position and velocity of the navigation receiver based on the validity status of the navigation data includes:

[0011] If the navigation data is valid, then obtain the position and velocity determined by the navigation receiver's orbit determination; where r x (t GNSS ), r y (t GNSS ), r z (t GNSS ), v x (t GNSS ), v y (t GNSS ), v z (t GNSS () represents the satellite position and velocity components in the J2000.0 coordinate system at time tGNSS.

[0012] Optionally, the satellite orbital elements include: distance and velocity values, angular momentum, semi-major axis, orbital angular velocity, eccentricity, orbital inclination, right ascension of the ascending node, argument of latitude, and argument of perigee.

[0013] Alternatively, the distance and speed values ​​can be calculated using the following formulas:

[0014]

[0015] The angular momentum is calculated using the following formula:

[0016]

[0017]

[0018] The semi-major axis is calculated using the following formula:

[0019]

[0020] Where μ = 3.986005E14;

[0021] The orbital angular velocity is calculated using the following formula:

[0022]

[0023] The eccentricity is calculated using the following formula:

[0024]

[0025] The track inclination angle is calculated using the following formula:

[0026]

[0027] The right ascension of the ascending node is calculated using the following formula:

[0028]

[0029] Ω = a tan 2(Ω) y ,Ω x )

[0030] The latitude argument is calculated using the following formula:

[0031]

[0032] u = a tan 2(u y ,u x )

[0033] The perigee argument is calculated using the following formula:

[0034]

[0035] E = arctan 2(e sin E, e cos E)

[0036]

[0037] ω=uf

[0038] In the formula, a is the orbital half-field axis, in meters; e is the eccentricity, without units; i is the orbital inclination, ranging from 0 to π, in rad; Ω is the right ascension of the ascending node, ranging from -π to π, in rad; u is the depression angle, ranging from -π to π, in rad; and w is the perigee depression angle, ranging from -π to π, in rad.

[0039] Optionally, the validity of the navigation data can be determined based on the satellite orbit elements calculated in the previous steps. If the eccentricity e is between 0.5 and 0.8 and the inclination i is greater than 0.85 to 1.25 rad, then the data is valid (FlagGNSS = 1); otherwise, the current shot is invalid (FlagGNSS = 0).

[0040] Optionally, the true anomaly angle and latitudinal argument of the orbital parameters at the current satellite moment can be extrapolated.

[0041] If t now (k)-t GPS ≤2(s), near-point angle E now (k) The update algorithm is as follows:

[0042] Δt=t now -t GPS

[0043]

[0044] If t now (k)-t GPS>2(s), near-point angle E now (k) The update algorithm is as follows:

[0045] Δt=t now (k)-t now (k-1)

[0046]

[0047] Based on the current near-point angle E now (k) Calculate the true anomaly and the argument of latitude:

[0048]

[0049] u now =ω+f now

[0050] Optionally, calculate the instantaneous orbital angular velocity df / dt;

[0051] Distance and speed values:

[0052] Angular momentum: H = ρ × v

[0053] Instantaneous orbital angular velocity calculation:

[0054] The technical solution provided by this invention may include the following beneficial effects:

[0055] This invention provides a GNSS-based orbit extrapolation method for highly elliptical frozen orbits. It extrapolates various elements of the satellite's orbit using only the orbital information at GNSS time, thereby completing the satellite's autonomous positioning and attitude control, reducing the satellite's positioning requirements for ground stations, and improving the satellite's autonomous capabilities.

[0056] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0057] To more clearly illustrate the technical solutions of the embodiments of this invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 This is a flowchart of the GNSS orbit extrapolation method for large elliptical frozen orbits in an embodiment of the present invention. Detailed Implementation

[0059] Embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be more thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0060] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0061] It should be understood that although the terms "first," "second," "third," etc., may be used to describe various steps in this invention, this information should not be limited to these terms. These terms are only used to distinguish steps of the same type from one another. For example, a first step may also be referred to as a second step without departing from the scope of this invention, and similarly, a second step may also be referred to as a first step. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0062] The technical solutions of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0063] Please see Figure 1 This embodiment provides a GNSS-based orbit extrapolation method for highly elliptical frozen orbits, including the following steps:

[0064] Step 1: If the navigation data is valid (Flag) GNSS =1), obtain the position and velocity of the navigation receiver for orbit determination; r x (t GNSS ), r y (t GNSS ), r z (t GNSS ), v x (t GNSS ), v y (t GNSS ), v z (t GNSS ) are respectively t GNSS Satellite position and velocity components in the J2000.0 coordinate system at time;

[0065] Step 2: Using tGNSS Calculate satellite orbital features using time, position, and velocity vectors;

[0066] 1) Distance and speed values:

[0067] 2) Angular momentum:

[0068] 3) Semi-major axis Where μ = 3.986005E14

[0069] 4) Orbital angular velocity

[0070] 5) Eccentricity

[0071] 6) Track inclination The value range is 0 to π.

[0072] 7) Right ascension of the ascending node

[0073]

[0074] Ω = a tan 2(Ω) y ,Ω x )

[0075] 8) Latitude Aspect

[0076]

[0077] u = a tan 2(u y ,u x )

[0078] 9) Argument of perigee

[0079]

[0080] E = arctan 2(e sin E, e cos E)

[0081]

[0082] ω=uf

[0083] In the formula, 'a' represents the orbital half-field axis, in meters (m).

[0084] e is the eccentricity, which has no unit.

[0085] i is the orbital inclination angle, ranging from 0 to π, in rad;

[0086] Ω is the right ascension of the ascending node, ranging from -π to π, in rad;

[0087] u is the angle of depression in the dimension, ranging from -π to π, in rad.

[0088] w is the perigee depression angle, ranging from -π to π, in rad.

[0089] Step 3: Determine the validity of the navigation data based on the satellite orbital elements calculated in the previous steps. If the eccentricity e is between 0.5 and 0.8, and the inclination i is greater than 0.85 to 1.25 rad, then the data is valid. (Flag) GNSS =1; otherwise, invalidate the current beat (Flag). GNSS =0;

[0090] Step 4: Extrapolate and calculate the orbital parameters (latitude and argument) at the current satellite moment;

[0091] If t now (k)-t GPS ≤2(s), near-point angle E now (k) The update algorithm is as follows:

[0092] Δt=t now -t GPS

[0093]

[0094] If t now (k)-t GPS >2(s), near-point angle E now (k) The update algorithm is as follows:

[0095] Δt=t now (k)-t now (k-1)

[0096]

[0097] Based on the current near-point angle E now (k) Calculate the true anomaly and the argument of latitude:

[0098]

[0099] u now =ω+f now

[0100] Step 5: Calculate the instantaneous orbital angular velocity df / dt.

[0101] Distance and speed values:

[0102] Angular momentum: H = ρ × v

[0103] Instantaneous orbital angular velocity calculation:

[0104] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of the present invention are included within the scope of protection of the present invention.

Claims

1. A GNSS-based extrapolation method for determining a highly elliptical frozen orbit, characterized in that, include: Based on the validity status of the navigation data, obtain the position and speed of the navigation receiver for orbit determination; Using t GNSS Calculate various elements of the satellite orbit based on its position and velocity vectors at time; The validity of navigation data is determined based on the calculation results of various satellite orbit elements. Extrapolate the orbital parameters, true anomaly angle and latitudinal argument, at the current satellite moment. Calculate the instantaneous orbital angular velocity and complete the GNSS-based orbit extrapolation design of a highly elliptical frozen orbit. The validity of the navigation data is determined based on the satellite orbital elements calculated in the previous steps, including eccentricity. e The tilt angle is between 0.5 and 0.

8. i If the value is greater than 0.85~1.25 rad, the data is considered valid. GNSS =1; Otherwise, invalidate the current shot flag. GNSS =0; Extrapolate the orbital parameters, true anomaly angle and latitudinal argument, at the current satellite moment. like (s), near-point angle The update algorithm is as follows: like (s), near-point angle The update algorithm is as follows: Based on the current near point angle Calculate the true anomaly and the argument of latitude: 。 2. The GNSS-based orbit extrapolation method for highly elliptical frozen orbits as described in claim 1, characterized in that, The step of obtaining the position and velocity of the navigation receiver based on the validity status of the navigation data includes: If the navigation data is valid, then obtain the position and velocity determined by the navigation receiver's orbit determination; among which, , They are respectively t GNSS Satellite position and velocity components in the J2000.0 coordinate system at time.

3. The GNSS-based orbit extrapolation method for highly elliptical frozen orbits as described in claim 2, characterized in that... The satellite orbital elements include: distance and velocity values, angular momentum, semi-major axis, orbital angular velocity, eccentricity, orbital inclination, right ascension of the ascending node, argument of latitude, and argument of perigee.

4. The GNSS orbit extrapolation method for highly elliptical frozen orbits as described in claim 3, characterized in that, The distance and speed values ​​are calculated using the following formula: ， The angular momentum is calculated using the following formula: ， The semi-major axis is calculated using the following formula: Where μ = 3.986005E14; The orbital angular velocity is calculated using the following formula: The eccentricity is calculated using the following formula: The track inclination angle is calculated using the following formula: The right ascension of the ascending node is calculated using the following formula: The latitude argument is calculated using the following formula: The perigee argument is calculated using the following formula: In the formula, a The axis of the orbital half-field is in meters (m). e The eccentricity is a unitless value. i The orbital inclination angle ranges from 0 to π, and is expressed in rad. Ω The right ascension of the ascending node is given, and its value ranges from -π to π, in rad. u The angle of depression is a dimension, ranging from -π to π, in rad. w The angle of depression at perigee ranges from -π to π, and is expressed in rad.

5. The GNSS-based orbit extrapolation method for highly elliptical frozen orbits as described in claim 1, characterized in that, Calculate the instantaneous orbital angular velocity df / dt; Distance and speed values: , angular momentum: Instantaneous orbital angular velocity calculation: .

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