Balloon satellite-based atmospheric wind field inversion method suitable for ultra-low orbit

Abstract

The invention discloses a balloon satellite-based atmospheric wind field inversion method suitable for an ultra-low orbit, and the method comprises the steps: P1, obtaining an air damping acceleration through the three-dimensional acceleration of a balloon satellite; p2, acquiring atmospheric density according to the air damping acceleration; step P3, acquiring the crosswind speed by using the acceleration vertical to the flight direction; and P4, obtaining the uncertainty of the atmospheric density and the crosswind speed. The invention discloses an atmospheric density and crosswind field detection means based on a balloon satellite, and provides feasibility for high-precision atmospheric density and crosswind field detection inversion by utilizing the advantage of constant surface-mass ratio of the balloon satellite. Under the condition that the acceleration calculation precision is certain, the influence of the surface-to-mass ratio S / m of the balloon satellite on the atmospheric density and the crosswind measurement precision is that the larger the surface-to-mass ratio is, the higher the measurement precision is.

Description

Technical Field

[0001] The present invention relates to the technical field of space environment monitoring. Specifically, it is a method for retrieving the atmospheric wind field based on a balloon satellite applicable to ultra-low orbits. Background Art

[0002] With the exploration, development, and utilization of space by humans, the detection of atmospheric parameters in ultra-low orbits (about 150 km to 300 km) has attracted increasing attention. Conducting research on the ultra-low orbit atmosphere will lay the foundation and provide important basic data for comprehensively and systematically studying the global atmosphere, and has extremely important application value and great significance for human living space and space, space science experiments, the launch and operation of space vehicles, strategic missile environmental support services, space exploration, and military meteorology, medium- and long-term weather forecasting of the upper atmosphere, etc.

[0003] In the detection of the ultra-low orbit atmospheric environment, traditional satellites are difficult to enter the ultra-low orbit state for continuous on-orbit monitoring of the atmospheric environment. The resistance of the ultra-low orbit atmosphere is relatively large, and it is difficult for satellites to maintain; as a result, there are relatively few historical detection data of atmospheric parameters and relatively little understanding. Currently, with the development of electric propulsion technology, satellites can maintain a relatively long time in ultra-low orbits, and the development and utilization of ultra-low orbits have attracted attention, so in-depth detection and research are required. Li Yongping and others independently designed and developed an in-situ detection payload for atmospheric density, which measures atmospheric pressure using the ionization rule and measures temperature using a temperature sensor, and fuses the data of multiple detectors to obtain the spatio-temporal distribution changes of atmospheric density, but it cannot give crosswind information.

[0004] Although on-orbit satellites can obtain precise orbital parameters and theoretically can be used to retrieve atmospheric density and crosswind, due to the different structures of on-orbit satellites, the surface-to-mass ratios of satellites with different viewing angles differ by about one order of magnitude or more, and using the orbital decay information of on-orbit satellites brings relatively large errors to the retrieval of atmospheric density and crosswind. Therefore, it is difficult to accurately retrieve atmospheric parameter information using on-orbit ultra-low orbit satellites. Summary of the Invention

[0005] For this reason, the technical problem to be solved by the present invention is to provide a method for accurately retrieving atmospheric density and wind field based on a balloon satellite applicable to ultra-low orbits, and to retrieve accurate atmospheric density and crosswind parameters through the precise orbital data of the balloon satellite.

[0006] To solve the above technical problem, the present invention provides the following technical solution:

[0007] A method for retrieving the atmospheric wind field based on a balloon satellite applicable to ultra-low orbits, comprising the following steps:

[0008] Step P1, obtaining the air damping acceleration using the three-dimensional acceleration of the balloon satellite;

[0009] Step P2: Obtain the atmospheric density from the air-damping acceleration;

[0010] Step P3: Obtain the crosswind speed using the acceleration perpendicular to the flight direction;

[0011] Step P4: Obtain the uncertainties of the atmospheric density and the crosswind speed.

[0012] In the above method for inverting the atmospheric wind field based on a balloon satellite applicable to ultra-low orbits, in step P1,

[0013] Through precise orbit calculation of the balloon satellite, obtain the three-dimensional acceleration of the balloon satellite

[0014] where, a x is the acceleration of the balloon satellite in the x direction, a y is the acceleration of the balloon satellite in the y direction, a z is the acceleration of the balloon satellite in the z direction.

[0015] In the above method for inverting the atmospheric wind field based on a balloon satellite applicable to ultra-low orbits, the air-damping acceleration a a along the satellite flight direction is:

[0016]

[0017] In Equation (1), represents the along-track speed of the balloon satellite relative to the air, approximately equal to the motion speed of the balloon satellite, v x is the motion speed of the balloon satellite in the x direction, v y is the motion speed of the balloon satellite in the y direction, v z is the motion speed of the balloon satellite in the z direction; represents the acceleration generated by other acting forces except the atmospheric damping force;

[0018] The specific form of

[0019]

[0020] In Equation (2), represents the gravitational force of the Earth's mass point, represents the non-spherical gravitational force, represents the gravitational force of the Sun's mass point, represents the gravitational force of the major planet's mass point, represents the radiation pressure acting force.

[0021] The above method for retrieving the atmospheric wind field based on a balloon satellite applicable to very low Earth orbits, in step P2, the atmospheric density calculation formula is:

[0022]

[0023] In formula (3), C d is the air resistance coefficient; ρ is the atmospheric density; S is the frontal area of the object; V is the relative motion speed of the balloon satellite and the air. Since the air speed is a small quantity compared to the satellite speed and can be neglected, thus V is approximately equal to the motion speed of the balloon satellite, m represents the mass of the balloon satellite.

[0024] The above method for retrieving the atmospheric wind field based on a balloon satellite applicable to very low Earth orbits, in step P3, the acceleration a v perpendicular to the flight direction is calculated as:

[0025]

[0026] In formula (4), represents the normal direction perpendicular to the orbital plane,

[0027]

[0028] where, respectively represent the position and motion speed vector of the balloon satellite; x, y, and z are the positions of the x-axis, y-axis, and z-axis respectively, represents the vector of the motion speed of the balloon satellite, v x is the motion speed of the balloon satellite in the x direction, v y is the motion speed of the balloon satellite in the y direction, v z is the motion speed of the balloon satellite in the z direction.

[0029] The above method for retrieving the atmospheric wind field based on a balloon satellite applicable to very low Earth orbits, uses the calculated acceleration a v perpendicular to the flight direction of the balloon satellite to calculate the crosswind speed:

[0030]

[0031] By transposing formula (5), the crosswind speed is obtained:

[0032]

[0033] In formulas (5) and (6), a v represents the acceleration perpendicular to the flight direction of the balloon satellite, W represents the crosswind speed, and sign(a v ) represents the sign of the acceleration.

[0034] In the above method for retrieving the atmospheric wind field based on a balloon satellite applicable to ultra-low orbits, in step P4, only the influence of a the solution error on the uncertainty of atmospheric parameter retrieval is considered, and the standard deviation of the random error of atmospheric density is obtained as:

[0035]

[0036] where Δρ is the standard deviation of the random error of atmospheric density, and Δa a is the standard deviation of the random error of air damping acceleration.

[0037] In the above method for retrieving the atmospheric wind field based on a balloon satellite applicable to ultra-low orbits, in step P4, only the influence of v the solution error on the uncertainty of atmospheric parameter retrieval is considered, and the standard deviation of the random error of crosswind velocity is obtained as:

[0038]

[0039] where ΔW is the standard deviation of the random error of crosswind velocity, and Δa v is the standard deviation of the random error of the acceleration perpendicular to the flight direction of the balloon satellite.

[0040] The technical solution of the present invention has achieved the following beneficial technical effects:

[0041] 1. Through the precise orbit (x, y, z; v x , v y , v z ; a x , a y , a z ) data of the balloon satellite, the atmospheric density and crosswind parameters are retrieved.

[0042] 2. The present patent proposes a means for detecting atmospheric density and crosswind based on a balloon satellite, and uses the advantage of the constant surface-to-mass ratio of the balloon satellite to provide feasibility for high-precision retrieval of atmospheric density and crosswind field.

[0043] 3. Under the condition of a certain acceleration solution accuracy, the influence of the surface-to-mass ratio S / m of the balloon satellite on the measurement accuracy of atmospheric density and crosswind is: the larger the surface-to-mass ratio, the higher the measurement accuracy. Specific embodiments

[0045] In ultra-low Earth orbit atmospheric environment exploration, traditional satellites are difficult to enter the ultra-low Earth orbit state for continuous on-orbit monitoring of the atmospheric environment. This patent proposes a method for detecting atmospheric density and crosswind based on a balloon satellite, which takes advantage of the constant surface-to-mass ratio of the balloon satellite to provide feasibility for high-precision inversion of atmospheric density and crosswind fields. This patent uses a drag resolution method to generate atmospheric density and crosswind data along the orbit. The specific method is as follows.

[0046] Step P1: Obtain the air drag acceleration using the three-dimensional acceleration of the balloon satellite;

[0047] Through precise orbit calculation of the balloon satellite, the three-dimensional acceleration of the balloon satellite is obtained

[0048] where a x is the acceleration of the balloon satellite in the x direction, a y is the acceleration of the balloon satellite in the y direction, a z is the acceleration of the balloon satellite in the z direction.

[0049] The air drag acceleration a a along the satellite flight direction is:

[0050]

[0051] In Equation (1), represents the along-track velocity of the balloon satellite relative to the air. Since the air wind speed is very small compared to the satellite's motion speed and can be ignored, so is approximately equal to the motion speed of the balloon satellite, V x is the motion speed of the balloon satellite in the x direction, v y is the motion speed of the balloon satellite in the y direction, v z is the motion speed of the balloon satellite in the z direction; represents the acceleration generated by other acting forces except the atmospheric drag force;

[0052] The specific form of

[0053]

[0054] In Equation (2), represents the gravitational force of the Earth's mass point, represents the non-spherical gravitational force, represents the gravitational force of the Sun's mass point, represents the gravitational force of the large planet's mass point, represents the radiation pressure acting force, and these parameters can be calculated using various models.

[0055] Step P2: Obtain the atmospheric density from the air-damping acceleration;

[0056] The formula for calculating the atmospheric density is:

[0057]

[0058] In Equation (3), C d is the air resistance coefficient; ρ is the atmospheric density; S is the frontal area of the object; V is the relative motion speed of the object with respect to the air. Since the air speed is a small quantity compared to the satellite speed and can be neglected, V is approximately equal to the motion speed of the balloon satellite, and m represents the mass of the balloon satellite.

[0059] Step P3: Obtain the crosswind speed from the acceleration perpendicular to the flight direction;

[0060] The acceleration a v perpendicular to the flight direction is calculated by the formula:

[0061]

[0062] In Equation (4), represents the normal direction perpendicular to the orbital plane,

[0063]

[0064] where represent the position and motion velocity vectors of the balloon satellite respectively; x, y, and z are the positions of the x-axis, y-axis, and z-axis respectively, represents the motion vector velocity of the balloon satellite, v x is the motion speed of the balloon satellite in the x direction, v y is the motion speed of the balloon satellite in the y direction, v z is the motion speed of the balloon satellite in the z direction.

[0065] Using the calculated acceleration a v perpendicular to the flight direction of the balloon satellite, calculate the crosswind speed:

[0066]

[0067] By transposing Equation (5), the crosswind speed is obtained:

[0068]

[0069] In Equations (5) and (6), a v represents the acceleration perpendicular to the flight direction of the balloon satellite, W represents the crosswind speed, and sign(a v ) represents the sign of the crosswind acceleration.

[0070] Step P4. Obtain the uncertainties of atmospheric density and crosswind speed

[0071] Only consider a a Solve for the influence of the solution error on the uncertainty of atmospheric parameter inversion, and the uncertainty of atmospheric density is obtained as follows:

[0072]

[0073] Δρ is the standard deviation of the random error of atmospheric density, and Δa a is the standard deviation of the random error of the air damping acceleration. (The uncertainty can be defined as the random error.)

[0074] Only consider a v Solve for the influence of the solution error on the uncertainty of atmospheric parameter inversion, and the uncertainty of crosswind speed is obtained as follows:

[0075]

[0076] where, ΔW is the standard deviation of the random error of crosswind speed, and Δa v is the standard deviation of the random error of the acceleration perpendicular to the flight direction of the balloon satellite.

[0077] As can be seen from Equation (7) and Equation (8), under the condition that the solution accuracy of the acceleration (a a and Δa v ) is certain, the influence of the surface-to-mass ratio S / m on the measurement accuracy of atmospheric density and crosswind is as follows: the larger the surface-to-mass ratio, the higher the measurement accuracy.

[0078] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the claims of this patent application.

Claims

1. A method for retrieving atmospheric wind fields based on balloon satellites applicable to ultra-low Earth orbits, characterized in that, It includes the following steps: Step P1: Obtain the air damping acceleration by using the three-dimensional acceleration of the balloon satellite; Step P2: Obtain the atmospheric density from the air damping acceleration; Step P3: Obtain the crosswind speed by using the acceleration perpendicular to the flight direction; Step P4: Obtain the uncertainties of the atmospheric density and the crosswind speed.

2. The method for inverting atmospheric wind field based on balloon satellite applicable to ultra-low orbit according to claim 1, characterized in that, In step P1, By performing precise orbital calculations on the balloon satellite, the three-dimensional acceleration of the balloon satellite is obtained. where a x is the acceleration of the balloon satellite in the x-direction, a y is the acceleration of the balloon satellite in the y-direction, a z is the acceleration of the balloon satellite in the z-direction.

3. A method for retrieving atmospheric wind fields based on balloon satellites applicable to ultra-low orbits according to claim 2, characterized in that, The air damping acceleration a in the satellite flight direction a is as follows: In formula (1), represents the along-track velocity of the balloon satellite relative to the air, approximately equal to the motion velocity of the balloon satellite, v x is the motion velocity of the balloon satellite in the x direction, v y is the motion velocity of the balloon satellite in the y direction, v z is the motion velocity of the balloon satellite in the z direction; represents the acceleration generated by other acting forces except the atmospheric damping force; The specific form is as follows: In formula (2), represents the gravitational force of the Earth's mass point, represents the non-spherical gravitational force, represents the gravitational force of the Sun's mass point, represents the gravitational force of the major planet's mass point, represents the radiation pressure force.

4. A method for retrieving atmospheric wind fields based on balloon satellites applicable to ultra-low orbits according to claim 3, characterized in that, In step P2, the calculation formula for the atmospheric density is: In Equation (3), C d is the air resistance coefficient; ρ is the atmospheric density; S is the frontal area of the object; V is the relative motion speed of the balloon satellite and the air. Since the air speed is a small quantity compared to the satellite speed and can be neglected, V is approximately equal to the motion speed of the balloon satellite. m represents the mass of the balloon satellite.

5. A method for inverting atmospheric wind fields based on balloon satellites applicable to ultra-low orbits according to claim 4, characterized in that, In step P3, the acceleration a perpendicular to the flight direction v is calculated by the formula: In formula (4), represents the normal direction perpendicular to the orbital plane, Among them, respectively represent the position and the velocity vector of the balloon satellite; x, y, and z are the positions on the x-axis, y-axis, and z-axis respectively, is the vector representing the velocity of the balloon satellite, v x is the velocity of the balloon satellite in the x direction, v y is the velocity of the balloon satellite in the y direction, v z is the velocity of the balloon satellite in the z direction.

6. A method for inverting atmospheric wind fields based on balloon satellites applicable to ultra-low orbits according to claim 5, characterized in that, Using the calculated acceleration a perpendicular to the flight direction of the balloon satellite v Calculate the crosswind speed: By transposing equation (5), the crosswind speed is obtained: In Equations (5) and (6), a v represents the acceleration perpendicular to the flight direction of the balloon satellite, W represents the crosswind speed, and sign(a v ) represents the sign of the acceleration.

7. A method for retrieving atmospheric wind fields based on balloon satellites applicable to ultra-low orbits according to claim 6, characterized in that, In step P4, only a is considered a By solving the influence of the solution error on the uncertainty of the atmospheric parameter inversion, the standard deviation of the random error of the atmospheric density is obtained as follows: where Δρ is the standard deviation of the random error of the atmospheric density, and Δa a is the standard deviation of the random error of the air damping acceleration.

8. A method for retrieving atmospheric wind fields based on balloon satellites applicable to ultra-low orbits according to claim 6, characterized in that, In step P4, only a is considered v By solving the influence of the solution error on the uncertainty of the atmospheric parameter inversion, the standard deviation of the random error of the crosswind speed is obtained as follows: where ΔW is the standard deviation of the random error of the crosswind speed, and Δa v is the standard deviation of the random error of the acceleration perpendicular to the flight direction of the balloon satellite.

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