阅读说明：本技术 适用于指向在轨航天器的地面天线导引方法 (Ground antenna guiding method suitable for pointing to in-orbit spacecraft ) 是由 俞航 杨珺 苏小明 吕旺 陆启省 郑渊 黄欣 李楠 于 2020-03-19 设计创作，主要内容包括：本发明提供适用于指向在轨航天器的地面天线导引方法,包括：惯性系卫星位置计算步骤：根据给定的目标时刻t<Sub>1</Sub>的星历信息,计算t<Sub>1</Sub>时刻卫星在惯性系下的位置R<Sub>wECI</Sub>；地固系卫星位置计算步骤：根据给定的目标时刻t<Sub>1</Sub>和所述卫星在惯性系下的位置R<Sub>wECI</Sub>,计算t<Sub>1</Sub>时刻卫星在地固系下的位置R<Sub>wECF</Sub>。本发明不依赖于仿真软件或过多假设内容,考虑卫星实际运行情况计算地面测站天线对卫星的指向,有效解决了地面站接收天线对卫星的指向控制问题,而且达到了比较高的指向精度。(The invention provides a ground antenna guiding method suitable for pointing to an on-orbit spacecraft, which comprises the following steps: calculating the position of the inertial system satellite: according to a given target time t 1 Computing t from ephemeris information of 1 Position R of time satellite under inertial system wECI (ii) a And a step of calculating the position of the earth-fixed satellite: according to a given target time t 1 And the position R of said satellite in the inertial system wECI Calculating t 1 Position R of time satellite under earth's fixation wECF . The invention does not depend on simulation software or excessive assumed contents, considers the actual running condition of the satellite to calculate the direction of the ground station antenna to the satellite, effectively solves the problem of controlling the direction of the ground station receiving antenna to the satellite, and achieves higher direction accuracy.)

1. A ground antenna guidance method suitable for pointing to an in-orbit spacecraft is characterized by comprising the following steps:

calculating the position of the inertial system satellite: according to a given target time t₁Computing t from ephemeris information of₁Position R of time satellite under inertial system_wECI；

And a step of calculating the position of the earth-fixed satellite: according to a given target time t₁And the position R of said satellite in the inertial system_wECICalculating t₁Position R of time satellite under earth's fixation_wECF；

And the antenna position calculation step of the earth-fixed system survey station: according to the longitude, latitude and elevation of the given ground measurement station antenna, the position R of the ground measurement station antenna under the ground fixation system is calculated_tECF；

And a step of calculating the position of the satellite in the station center system: according to the t₁Position R of time satellite under earth's fixation_wECFAnd the position R of the ground survey station antenna under the ground fixing system_tECFCalculating t₁Position R of time satellite under the system of the center of the station_wCT；

The method comprises the following steps of (1) calculating the pointing guide angle of the survey station antenna: calculating t according to the position of the satellite under the station center system₁The antenna pointing guidance angle of the ground survey station at the moment: high and low angleHorizontal angle psi. The antenna pointing guiding process is completed through the two pointing guiding angles.

2. A method for guiding a ground antenna adapted to be pointed at an in-orbit spacecraft as claimed in claim 1, wherein the calculation t in said inertial system satellite position calculation step₁Position R of time satellite under inertial system_wECIThe method comprises the following steps:

inputting a target time t₁Includes: the device comprises a track semi-major axis a, a track eccentricity e, a track inclination angle i, a rising intersection declination omega, an argument omega of a near place and an average and near point angle M;

calculating t₁Position R of time satellite under inertial system_wECI：

R_wECI＝Q*r_p

Wherein the rotation matrix Q is described in a 3-1-3 rotation order:

vector r_p：

Wherein M is₁True proximal angle:

3. a method for guiding a terrestrial antenna adapted to be directed to an in-orbit spacecraft as claimed in claim 1, wherein the calculation t in the step of calculating the position of the geostationary satellite is₁The method of the position of the time of day satellites in the earth's fixation is as follows:

according to a given target time t₁Calculating a second count value t of epoch J2000.0 to a predetermined target time_cInputting t₁Year, month, day, hour, minute, second of the moment, calculate julian day JD:

wherein, floor () is a round-down operation;

calculating a second count value t from epoch J2000.0 to a given target time based on the julian day JD_c：

t_c＝(JD-2455197.5)×86400+315547200

According to the epoch J2000.0 obtained by calculation to the second counting value t of the given target time_cCalculating a rotation matrix ER, a nutation matrix NR and a precision matrix PR of the earth, and calculating a conversion matrix M from an inertia system to a ground-fixed system_ECI2ECF：

M_ECI2ECF＝ER*NR*PR

T is obtained according to the calculation₁Position R of time satellite under inertial system_wECIAnd the calculated transformation matrix M from the inertial system to the earth-fixed system_ECI2ECFCalculating t₁Position R of time satellite under earth's fixation_wECF：

R_wECF＝M_ECI2ECF*R_wECI

4. The method of claim 1, wherein the step of calculating the position of the ground station antenna calculates the position R of the ground station antenna in the ground system_tECFThe method comprises the following steps:

inputting longitude lon, latitude lat and elevation h of an antenna of the ground station;

computing coordinate components G1, G2:

wherein the content of the first and second substances,

re represents the Earth's equatorial radius;

f is the geometric oblateness of the earth ellipsoid, and f is 1/298.257;

calculating the position R of the ground survey station antenna under the ground fixing system_tECF：

5. A method for guiding a ground antenna adapted to be directed to an in-orbit spacecraft as claimed in claim 1, wherein said calculating t in said step of calculating the position of the satellite in the constellation is performed₁The method for the position of the time of day satellite under the station center system is as follows:

under the system of the station center, a conversion matrix M from the earth fixation system to the system of the station center is calculated_ECF2CTDescribed as one rotation about the Z-axis of the earth fixation system and one rotation about the X-axis of the earth fixation system:

M_ECF2CT＝R_x(90°-lat)R_z(90°+lon)

wherein lon is the geographic longitude of the antenna of the ground survey station; lat is the geographical latitude of the antenna of the ground station;

t is obtained according to the calculation₁Position R of time satellite under earth's fixation_wECFPosition R of the ground station antenna under the ground anchor_tECFAnd a transformation matrix M tied to the site-centric system_ECF2CTTranslating the origin of coordinates from the geocentric to the antenna of the ground survey station, and calculating t₁Position R of time satellite under the system of the center of the station_wCT：

R_wCT＝M_ECF2CT*(R_wECF-R_tECF)

6. A ground antenna guidance method suitable for pointing at an in-orbit spacecraft as claimed in claim 2, wherein said station antenna pointing guidance angle calculation step calculates a ground station antenna pointing guidance angle:

the high and low angles and the horizontal angle are defined under the station center system O_CTX_CTY_CTZ_CTIn, O_CTRepresenting the origin of the coordinate system, X_CTX-axis, Y, representing a coordinate system_CTY-axis, O, representing a coordinate system_CTX_CTY_CTThe plane, elevation angle, of X-axis and Y-axis of the coordinate systemTo point to a vector R_wCTAnd O_CTX_CTY_CTAngle of plane, define R_wCTVector sum of O_CTZ_CTThe included angle is less than 90 degrees and is positive; the horizontal angle psi being the director vector R_wCTAt O_CTX_CTY_CTProjection of plane and O_CTX_CTAngle of axis, defined around O_CTZ_CTShaft driven O_CTX_CTShaft clockwise steering pointing vector R_wCTAt O_CTX_CTY_CTThe projection of the surface is positive, and the antenna pointing angle is determined according to this definition. Assuming that the position of the ground survey station is located at the origin of the station center system, the projection of the antenna pointing vector of the survey station under the station center system is R_wCTRecord R_wCTComprises the following steps:

wherein the content of the first and second substances,

x_CT、y_CT、z_CTrespectively representing the pointing vectors R of antennas of the stations_wCTAt the station center is O_CTX_CTY_CTZ_CTCoordinate components of corresponding X-axis, Y-axis and Z-axis;

calculating elevation angle of antenna pointing guiding angleThe horizontal angle ψ is:

and according to x_CT、y_CT、z_CTPositive and negative of (2), angle of elevation

if z is_CTMore than or equal to 0, the height and angle will be changedDivision into ranges

If x_CT≥0,y_CTThe horizontal angle psi is divided into ranges

If x_CT＜0,y_CTThe horizontal angle psi is divided into ranges

If x_CT＜0,y_CTIf < 0, the horizontal angle psi is divided into ranges

If x_CT≥0,y_CTIf < 0, the horizontal angle psi is divided into ranges

Technical Field

The invention relates to the field of satellite attitude and orbit control, in particular to a ground antenna guiding method suitable for pointing to an in-orbit spacecraft.

Background

The radar plays a very important role in the scientific and technological construction of China, and along with the requirements of detecting and controlling an outer space target, the practical radar is rapidly developed and is applied to a plurality of important fields such as guidance, beyond-the-horizon detection and the like at present. With the development of the space detection technology, higher and higher requirements are put forward on the tracking and searching capabilities of a radar antenna, and as satellite signals are weak and have strong directivity, in order to capture communication signals on a moving satellite, the deviation between the attitude of the antenna and the position of the satellite must be adjusted in real time to meet the communication requirements, because the signal-to-noise ratio of link transmission information is reduced due to the satellite-to-ground directional deviation, and if the signal-to-noise ratio exceeds the maximum station position tolerance, the phenomenon of signal loss even occurs. This requires that the radar antenna must be pointed according to the command to track the moving target in real time. Therefore, the dynamic precision of the radar antenna pointing process becomes one of the important indexes of the antenna system function, and the design of the pointing calculation method with high pointing precision has general practical significance.

The method is characterized in that the pointing guidance of the ground survey station antenna to the satellite is mainly to calculate the antenna pointing guidance angle at a target moment according to the orbit information and the time information of the satellite and the position information of the ground survey station antenna, and realize the accurate pointing to the satellite at the target moment through the antenna pointing control.

The existing research on satellite-ground pointing algorithms in China mostly focuses on the optimization design of pointing of a satellite to a ground survey station under the condition that the position of the ground survey station is fixed, and the research on the pointing guidance of a ground survey station antenna to the satellite is less. Under the condition that the ground survey station is movable, under the condition that the geographical longitude, latitude and elevation of the ground survey station are known and the track information of the on-orbit aircraft is tracked, the pointing guidance of the aircraft is automatically finished, and the pointing guidance angle of the antenna is calculated in real time. Aiming at the actual situation, the invention provides a ground station real-time positioning method with higher precision for a ground station antenna, and the ground station antenna can be used for realizing the autonomous pointing guidance of a satellite.

The patent "design method of deep space probe antenna pointing" (patent number: CN104369877A) describes a method for pointing the deep space probe antenna to the center of the earth, which is used to realize the direction of the deep space probe antenna to the center of the earth. The patent is directed to the orientation of the antenna to the earth's center rather than a given position of the earth's surface, and directly gives the pointing vector of the detector antenna to the earth's center, without an algorithm for calculating the satellite position through orbital parameters. The method is different from the method in that a method for calculating the satellite pointing direction of the ground station aiming at the given position of the earth surface is designed, the positioning calculation of the ground station is completed, and a calculation process for calculating the ground station-satellite pointing vector through the satellite orbit parameter at the given moment is designed.

The patent "simulation analysis method of pointing angle of data transmission antenna" (patent number: CN105184002A) introduces a method for calculating pointing direction of satellite-borne data transmission antenna to ground station, which uses existing satellite orbit simulation software STK to perform simulation solution on actual position of satellite and calculates two-dimensional pointing angle of data transmission antenna. The defects of the patent are that the satellite position calculation depends on satellite orbit simulation software STK, no specific calculation process is needed, the description of coordinate system conversion is simple, and an algorithm of a conversion matrix is not given. The invention has the advantages of providing a method for calculating the actual position of the satellite according to the orbit parameters of the satellite at the appointed time without depending on STK software and designing a set of detailed calculation flow of a related coordinate system conversion matrix.

The patent "a method for controlling the pointing direction of a dual-axis antenna to the ground around a moon satellite" (patent number: CN101204994A) discloses a method for calculating the pointing direction of a satellite to the center of the earth around a moon satellite, wherein the position of the satellite is calculated according to ephemeris data on the ground, the visible area of the satellite to the earth is calculated, and the pointing angle of the dual-axis antenna is calculated. The patent is directed to the geocenter, does not orient the surface location, and is mainly calculated in combination with a moon-related coordinate system. The invention is different from the method in that the position calculation of the antenna of the ground survey station and the directional calculation of the antenna of the ground survey station to the satellite are completed mainly by combining the calculation of the relative coordinate systems of the earth and the earth surface position, and the definition and the calculation method of the directional angle of the antenna are different.

The literature, "pointing algorithm and simulation of satellite sharp beam antenna" (see "Chinese space science and technology", 2008, 2 nd), introduces an algorithm for pointing a satellite-borne sharp beam antenna to an earth surface target point, and the method has the disadvantages that many influence factors are ignored in the process of converting a coordinate system, influences such as time difference and nutation are not considered, and pointing accuracy is low. The invention deduces formulas on the influence caused by the possible error factors, so that the coordinate system conversion process is more accurate.

Disclosure of Invention

In view of the defects in the prior art, the invention aims to provide a ground antenna guiding method suitable for pointing to an on-orbit spacecraft.

The ground antenna guiding method suitable for pointing to the on-orbit spacecraft provided by the invention comprises the following steps:

calculating the position of the inertial system satellite: according to a given target time t₁Computing t from ephemeris information of₁Position R of time satellite under inertial system_wECI；

And a step of calculating the position of the earth-fixed satellite: according to a given target time t₁And the position R of said satellite in the inertial system_wECICalculating t₁Position R of time satellite under earth's fixation_wECF；

And the antenna position calculation step of the earth-fixed system survey station: according to the longitude, latitude and elevation of the given ground measurement station antenna, the position R of the ground measurement station antenna under the ground fixation system is calculated_tECF；

And a step of calculating the position of the satellite in the station center system: according to the t₁Position R of time satellite under earth's fixation_wECFAnd the ground survey station antenna is on the groundPosition R under anchoring_tECFCalculating t₁Position R of time satellite under the system of the center of the station_wCT；

The method comprises the following steps of (1) calculating the pointing guide angle of the survey station antenna: calculating t according to the position of the satellite under the station center system₁The antenna pointing guidance angle of the ground survey station at the moment: high and low angleHorizontal angle psi. The antenna pointing guiding process is completed through the two pointing guiding angles.

Preferably, the calculation t in the inertial system satellite position calculation step₁Position R of time satellite under inertial system_wECIThe method comprises the following steps:

inputting a target time t₁Includes: the device comprises a track semi-major axis a, a track eccentricity e, a track inclination angle i, a rising intersection declination omega, an argument omega of a near place and an average and near point angle M;

calculating t₁Position R of time satellite under inertial system_wECI：

R_wECI＝Q*r_p

Wherein the rotation matrix Q is described in a 3-1-3 rotation order:

vector r_p：

Wherein M is₁True proximal angle:

preferably, the calculation t in the geostationary satellite position calculation step₁The method for the position of the time satellite under the earth's fixation is as follows:

according to a given target momentt₁Calculating a second count value t of epoch J2000.0 to a predetermined target time_cInputting t₁Year, month, day, hour, minute, second of the moment, calculate julian day JD:

wherein, floor () is a round-down operation;

calculating a second count value t from epoch J2000.0 to a given target time based on the julian day JD_c：

t_c＝(JD-2455197.5)×86400+315547200

According to the epoch J2000.0 obtained by calculation to the second counting value t of the given target time_cCalculating an earth self-torque matrix ER, a nutation matrix NR and a precision matrix PR, and calculating a conversion matrix M from an inertia system to a ground-fixed system_ECI2ECF：

M_ECI2ECF＝ER*NR*PR

T is obtained according to the calculation₁Position R of time satellite under inertial system_wECIAnd the calculated transformation matrix M from the inertial system to the earth-fixed system_ECI2ECFCalculating t₁Position R of time satellite under earth's fixation_wECF：

R_wECF＝M_ECI2ECF*R_wECI

Preferably, the position R of the ground station antenna under the ground system is calculated in the step of calculating the position of the ground station antenna under the ground system_tECFThe method comprises the following steps:

inputting longitude lon, latitude lat and elevation h of an antenna of the ground station;

computing coordinate components G1, G2:

wherein the content of the first and second substances,

re represents the Earth's equatorial radius;

f is the geometric oblateness of the earth ellipsoid, and f is 1/298.257;

calculating the position R of the ground survey station antenna under the ground fixing system_tECF：

Preferably, the calculation t in the step of calculating the position of the satellite in the satellite system of the center of the station₁The method for the position of the time of day satellites under the station center system is as follows:

under the system of the station center, a conversion matrix M from the earth fixation system to the system of the station center is calculated_ECF2CTDescribed as one rotation about the Z-axis of the earth fixation system and one rotation about the X-axis of the earth fixation system:

M_ECF2CT＝R_x(90°-lat)R_z(90°+lon)

wherein lon is the geographic longitude of the antenna of the ground survey station; lat is the geographical latitude of the antenna of the ground station;

t is obtained according to the calculation₁Position R of time satellite under earth's fixation_wECFPosition R of the ground station antenna under the ground anchor_tECFAnd a transformation matrix M tied to the site-centric system_ECF2CTTranslating the origin of coordinates from the geocentric to the antenna of the ground survey station, and calculating t₁Position R of time satellite under the system of the center of the station_wCT：

R_wCT＝M_ECF2CT*(R_wECF-R_tECF)

Preferably, the ground station antenna pointing guidance angle is calculated in the station antenna pointing guidance angle calculation step:

high-low angle and horizontal angleDefined under the station center system, defined under the station center system O_CTX_CTY_CTZ_CTIn, O_CTRepresenting the origin of the coordinate system, X_CTX-axis, Y, representing a coordinate system_CTY-axis, O, representing a coordinate system_CTX_CTY_CTThe plane, elevation angle, of X-axis and Y-axis of the coordinate system

To point to a vector R_wCTAnd O_CTX_CTY_CTAngle of plane, define R_wCTVector sum of O_CTZ_CTThe included angle is less than 90 degrees and is positive; the horizontal angle psi being the director vector R_wCTAt O_CTX_CTY_CTProjection of plane and O_CTX_CTIncluded angle of axis, defined around O_CTZ_CTShaft driven O_CTX_CTShaft clockwise steering pointing vector R_wCTAt O_CTX_CTY_CTThe projection of the surface is positive, and the antenna pointing angle is determined according to this definition. Assuming that the position of the ground survey station is located at the origin of the station center system, the projection of the antenna pointing vector of the survey station under the station center system is R_wCTRecord R_wCTComprises the following steps:

wherein the content of the first and second substances,

x_CT、y_CT、z_CTrespectively representing the pointing vectors R of antennas of the stations_wCTAt the station center is O_CTX_CTY_CTZ_CTCoordinate components of corresponding X-axis, Y-axis and Z-axis;

calculating elevation angle of antenna pointing guiding angleThe horizontal angle ψ is:

and according to x_CT、y_CT、z_CTPositive and negative of (2), angle of elevationDividing the horizontal angle psi into corresponding angle ranges to complete the antenna pointing guidance process:

if z is_CTMore than or equal to 0, the height and angle will be changed

Division into ranges

If x_CT≥0,y_CTThe horizontal angle psi is divided into ranges

If x_CT＜0,y_CTThe horizontal angle psi is divided into ranges

If x_CT＜0,y_CTIf < 0, the horizontal angle psi is divided into ranges

If x_CT≥0,y_CTIf < 0, the horizontal angle psi is divided into ranges

Compared with the prior art, the invention has the following beneficial effects:

the invention does not depend on simulation software or excessive assumed contents, considers the actual running condition of the satellite to calculate the direction of the ground station antenna to the satellite, effectively solves the problem of controlling the direction of the ground station receiving antenna to the satellite, and achieves higher direction accuracy.

Drawings

Other features, objects and advantages of the present invention will become more apparent upon reading of the detailed description of the non-limiting embodiments with reference to the following drawings:

fig. 1 is a schematic diagram illustrating a calculation process of a satellite pointing direction guidance by a ground station antenna.

Fig. 2 is a schematic diagram of the direction guidance of the ground station antenna to the satellite.

FIG. 3 shows a standing system O_CTX_CTY_CTZ_CTSchematic representation.

FIG. 4 shows the elevation angle of the standing heart systemAnd horizontal angle psi.

FIG. 5 is a schematic diagram of a variation curve of satellite positions under the inertial system.

FIG. 6 is a diagram illustrating a variation curve of the position of a satellite in the Earth's fixation system.

Fig. 7 is a schematic diagram of a projection variation curve of the pointing vector of the station antenna to the satellite under the station center system.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

The ground antenna guiding method suitable for pointing to the on-orbit spacecraft provided by the invention comprises the following steps:

calculating the position of the inertial system satellite: according to a given target time t₁Computing t from ephemeris information of₁Position R of time satellite under inertial system_wECI；

And a step of calculating the position of the earth-fixed satellite: according to a given target time t₁And the position R of said satellite in the inertial system_wECICalculating t₁Position R of time satellite under earth's fixation_wECF；

And the antenna position calculation step of the earth-fixed system survey station: according to the longitude, latitude and elevation of the given ground measurement station antenna, the position R of the ground measurement station antenna under the ground fixation system is calculated_tECF；

And a step of calculating the position of the satellite in the station center system: according to the t₁Position R of time satellite under earth's fixation_wECFAnd the position R of the ground survey station antenna under the ground fixing system_tECFCalculating t₁Position R of time satellite under the system of the center of the station_wCT；

The method comprises the following steps of (1) calculating the pointing guide angle of the survey station antenna: calculating t according to the position of the satellite under the station center system₁The antenna pointing guidance angle of the ground survey station at the moment: high and low angle

Horizontal angle psi. The antenna pointing guiding process is completed through the two pointing guiding angles.

Specifically, the calculation t in the inertial system satellite position calculation step₁Position R of time satellite under inertial system_wECIThe method comprises the following steps:

inputting a target time t₁Includes: the device comprises a track semi-major axis a, a track eccentricity e, a track inclination angle i, a rising intersection declination omega, an argument omega of a near place and an average and near point angle M;

calculating t₁Position R of time satellite under inertial system_wECI：

R_wECI＝Q*r_p

Wherein the rotation matrix Q is described in a 3-1-3 rotation order:

vector r_p：

Wherein M is₁True proximal angle:

specifically, the calculation t in the geostationary satellite position calculation step₁The method for the position of the time satellite under the earth's fixation is as follows:

according to a given target time t₁Calculating a second count value t of epoch J2000.0 to a predetermined target time_cInputting t₁Year, month, day, hour, minute, second of the moment, calculate julian day JD:

wherein, floor () is a round-down operation;

calculating a second count value t from epoch J2000.0 to a given target time based on the julian day JD_c：

t_c＝(JD-2455197.5)×86400+315547200

According to the epoch J2000.0 obtained by calculation to the second counting value t of the given target time_cCalculating an earth self-torque matrix ER, a nutation matrix NR and a precision matrix PR, and calculating a conversion matrix M from an inertia system to a ground-fixed system_ECI2ECF：

M_ECI2ECF＝ER*NR*PR

T is obtained according to the calculation₁Position R of time satellite under inertial system_wECIAnd the calculated transformation matrix M from the inertial system to the earth-fixed system_ECI2ECFCalculating t₁Position R of time satellite under earth's fixation_wECF：

R_wECF＝M_ECI2ECF*R_wECI

Specifically, the position of the antenna of the ground fixed system survey station is calculated in the step of calculating the position of the antenna of the ground survey station on the groundPosition R under anchoring_tECFThe method comprises the following steps:

inputting longitude lon, latitude lat and elevation h of an antenna of the ground station;

computing coordinate components G1, G2:

wherein the content of the first and second substances,

re represents the Earth's equatorial radius;

f is the geometric oblateness of the earth ellipsoid, and f is 1/298.257;

calculating the position R of the ground survey station antenna under the ground fixing system_tECF：

Specifically, the calculation t in the step of calculating the position of the satellite in the center of the station₁The method for the position of the time of day satellites under the station center system is as follows:

under the system of the station center, a conversion matrix M from the earth fixation system to the system of the station center is calculated_ECF2CTDescribed as one rotation about the Z-axis of the earth fixation system and one rotation about the X-axis of the earth fixation system:

M_ECF2CT＝R_x(90°-lat)R_z(90°+lon)

wherein lon is the geographic longitude of the antenna of the ground survey station; lat is the geographical latitude of the antenna of the ground station;

t is obtained according to the calculation₁Time of day satellite is fixed on groundPosition of being tethered R_wECFPosition R of the ground station antenna under the ground anchor_tECFAnd a transformation matrix M tied to the site-centric system_ECF2CTTranslating the origin of coordinates from the geocentric to the antenna of the ground survey station, and calculating t₁Position R of time satellite under the system of the center of the station_wCT：

R_wCT＝M_ECF2CT*(R_wECF-R_tECF)

Specifically, the calculation of the pointing guidance angle of the station antenna in the step of calculating the pointing guidance angle of the station antenna includes:

the high and low angles and the horizontal angle are defined under the station center system O_CTX_CTY_CTZ_CTIn, O_CTRepresenting the origin of the coordinate system, X_CTX-axis, Y, representing a coordinate system_CTY-axis, O, representing a coordinate system_CTX_CTY_CTThe plane, elevation angle, of X-axis and Y-axis of the coordinate systemTo point to a vector R_wCTAnd O_CTX_CTY_CTAngle of plane, define R_wCTVector sum of O_CTZ_CTThe included angle is less than 90 degrees and is positive; the horizontal angle psi being the director vector R_wCTAt O_CTX_CTY_CTProjection of plane and O_CTX_CTIncluded angle of axis, defined around O_CTZ_CTShaft driven O_CTX_CTShaft clockwise steering pointing vector R_wCTAt O_CTX_CTY_CTThe projection of the surface is positive, and the antenna pointing angle is determined according to this definition. Assuming that the position of the ground survey station is located at the origin of the station center system, the projection of the antenna pointing vector of the survey station under the station center system is R_wCTRecord R_wCTComprises the following steps:

wherein the content of the first and second substances,

x_CT、y_CT、z_CTare respectively provided withIndicating the direction vector R of the antenna of the survey station_wCTAt the station center is O_CTX_CTY_CTZ_CTCoordinate components of corresponding X-axis, Y-axis and Z-axis;

calculating elevation angle of antenna pointing guiding angleThe horizontal angle ψ is:

and according to x_CT、y_CT、z_CTPositive and negative of (2), angle of elevationDividing the horizontal angle psi into corresponding angle ranges to complete the antenna pointing guidance process:

if z is_CTMore than or equal to 0, the height and angle will be changed

Division into ranges

If x_CT≥0,y_CTThe horizontal angle psi is divided into ranges

If x_CT＜0,y_CTThe horizontal angle psi is divided into ranges

If x_CT＜0,y_CTIf < 0, the horizontal angle psi is divided into ranges

If x_CT≥0,y_CTIf < 0, the horizontal angle psi is divided into ranges

The present invention will be described more specifically below with reference to preferred examples.

Preferred example 1:

the technical problem to be solved by the invention is as follows: the method comprises the steps of performing satellite orbit correlation calculation and conversion calculation of a plurality of correlation coordinate systems by satellite ephemeris data and geographical position information of a ground station antenna at a given target moment, and finally converting the satellite ephemeris data and the geographical position information into an antenna pointing guidance angle under a station center system to complete the pointing guidance process of the ground station antenna to a satellite.

The invention combines a practical engineering situation: under the condition that the ground survey station is movable, under the condition that the geographical longitude, latitude and elevation of the ground survey station are known and the track information of the on-orbit aircraft is tracked, the pointing tracking of the aircraft is automatically completed, and the antenna pointing guiding angle is calculated in real time. The ground measurement station real-time positioning method is used for a ground measurement station antenna with high precision, and the ground measurement station antenna can guide the satellite in an autonomous pointing mode.

The ground antenna guidance method suitable for the pointing in-orbit spacecraft calculates the position of the satellite in real time through satellite ephemeris information, considers influence factors of a coordinate system conversion relation comprehensively, has high calculation precision, provides the pointing guidance angle definition suitable for the ground station antenna, and effectively meets the requirement of the ground station antenna on real-time satellite pointing guidance.

The technical solution of the invention comprises the following steps:

(1) according to a given target time (UTC time) t₁Computing t from ephemeris information of₁Position R of time satellite under inertial system_wECIThe method comprises the following steps:

inputting a target time t₁Includes: the track comprises a semi-major axis a of the track, an eccentricity e of the track, a track inclination angle i, a rising intersection declination omega, an amplitude angle omega at a near place and an average angle M at a near point. Calculating t₁Position R of time satellite under inertial system_wECI：

R_wECI＝Q*r_p

Wherein the rotation matrix Q is described in a 3-1-3 rotation order:

vector r_p：

Wherein M is₁True proximal angle:

(2) according to a given target time t₁And the position R of the satellite calculated in the step (1) under the inertial system_wECICalculating t₁Position R of time satellite under earth's fixation_wECFThe method comprises the following steps:

(2.1) according to a given target time t₁A second counting value t from epoch J2000.0 (1/12/2000) to a predetermined target time is calculated_c；

(2.2) calculating a second counting value t from epoch J2000.0 (1 month, 1 day, 12 hours in 2000) to a given target time according to the step (2.1)_cAnd calculating a terrestrial rotation matrix ER, a nutation matrix NR and a time offset matrix PR, wherein the term is not considered in the invention because polar shift has little influence on the calculation of the conversion matrix. Calculating a transformation matrix M from an inertial system to a ground-based system_ECI2ECF：

M_ECI2ECF＝ER*NR*PR

(2.3) calculating according to the step (1)T of₁Position R of time satellite under inertial system_wECIAnd the transformation matrix M of the inertial system to the earth-fixed system calculated in the step (2.2)_ECI2ECFCalculating t₁Position R of time satellite under earth's fixed system_wECF：

R_wECF＝M_ECI2ECF*R_wECI

(3) According to the longitude, latitude and elevation of the given ground measurement station antenna, the position R of the ground measurement station antenna under the ground fixation system is calculated_tECFThe method comprises the following steps:

and inputting longitude lon, latitude lat and elevation h of the antenna of the ground station.

Computing coordinate components G1, G2:

wherein f is the geometric oblateness of the earth ellipsoid, and f is 1/298.257.

Calculating the position R of the ground survey station antenna under the ground fixing system_tECF：

(4) T calculated according to the step (2)₁Position R of time satellite under earth's fixation_wECFAnd the position R of the ground survey station antenna calculated in the step (3) under the ground system_tECFCalculating t₁Position R of time satellite under the system of the center of the station_wCTThe method comprises the following steps:

(4.1) under the station center system, calculating a conversion matrix M from the earth fixed system to the station center system_ECF2CTDescribed as one rotation about the Z-axis of the earth fixation system and one rotation about the X-axis of the earth fixation system:

M_ECF2CT＝R_x(90°-lat)R_z(90°+lon)

wherein lon is the geographic longitude of the antenna of the ground survey station; lat is the geographic latitude of the ground station antenna.

(4.2) t calculated according to the step (2)₁Position R of time satellite under earth's fixation_wECFThe position R of the ground survey station antenna under the ground fixing system obtained by the calculation in the step (3)_tECFThe conversion matrix M from the earth fixation system to the station center system calculated in the step (4.1)_ECF2CTTranslating the origin of coordinates from the geocentric to the ground station antenna, and calculating t₁Position R of time satellite under the system of the center of the station_wCT：

R_wCT＝M_ECF2CT*(R_wECF-R_tECF)

(5) Calculating t according to the position of the satellite under the station center system calculated in the step (4)₁The antenna pointing guide angle of the ground survey station at the moment: high and low angleHorizontal angle ψ by the following method:

the high and low angles and the horizontal angle are defined under the station center systemTo point to a vector R_wCTAnd O_CTX_CTY_CTIncluded angle of plane, define R_wCTVector sum of O_CTZ_CTThe included angle is less than 90 degrees and is positive; the horizontal angle psi being the director vector R_wCTAt O_CTX_CTY_CTProjection of plane and O_CTX_CTAngle of axis, defined around O_CTZ_CTShaft driven O_CTX_CTShaft clockwise steering pointing vector R_wCTAt O_CTX_CTY_CTThe projection of the surface is positive, as shown in FIG. 4The antenna pointing angle is determined according to this definition. Assuming that the position of the ground survey station is located at the origin of the station center system, the projection of the antenna pointing vector of the survey station under the station center system is R_wCTRecord R_wCTComprises the following steps:

calculating elevation angle of antenna pointing guiding angleThe horizontal angle ψ is:

and according to x_CT、y_CT、z_CTPositive and negative of (2), angle of elevationDividing the horizontal angle psi into corresponding angle ranges to complete the antenna pointing guidance process:

preferred example 2:

the coordinate system required by the invention is as follows: the inertial system is a J2000.0 inertial coordinate system, and the earth fixation system is a WGS-84 coordinate system. The definition of the station center system is given below.

Standing heart system O_CTX_CTY_CTZ_CT

The center of the station is defined as the origin O_CTIs the ground antenna origin, the basic plane O_CTX_CTY_CTThe surface is a local horizontal surface, O_CTX_CTPointing to true north, O, along the meridian of the local area_CTZ_CTIs vertical and substantially flatSurface pointing to zenith, O_CTY_CTDetermined by the right hand rule, as shown in FIG. 3.

The calculation process of the present invention is detailed below:

the MATLAB is used for carrying out simulation verification on the algorithm, the earth related parameters and the station center system are set as described above, and ephemeris data of a certain type of satellite at UTC time of 2018, 12, 3 and 5 are as follows:

the satellite pointing tracking is carried out from 5 hours and 30 minutes in 12 months, 3 days and 5 days in 2018 of UTC time, the simulation step length is 1s, the antenna pointing guiding angles (high and low angles and horizontal angles) are continuously simulated for 30 minutes, and satellite ephemeris data of every 1s serving as input are obtained through STK simulation.

(1) According to a given target time (UTC time) t₁Computing t from ephemeris information of₁Position R of time satellite under inertial system_wECI. The specific calculation process is as follows:

according to t₁Includes: the track comprises a semi-major axis a of the track, an eccentricity e of the track, a track inclination angle i, a rising intersection declination omega, an amplitude angle omega at a near place and an average angle M at a near point. Calculating t₁Position R of time satellite under inertial system_wECIThe obtained satellite position variation curve under the inertial system is shown in fig. 5:

R_wECI＝Q*r_p

wherein the rotation matrix Q is described in a 3-1-3 rotation order:

vector r_p：

Wherein M is₁True proximal angle:

(2) according to a given target time t₁And the position R of the satellite calculated in the step (1) under the inertial system_wECICalculating t₁Position R of time satellite under earth's fixation_wECF. The method comprises the following specific steps:

(2.1) input of t₁Year (year), month (month), day (day), hour (hour), minute (min), and second (sec) of time (UTC time), julian day JD is calculated:

wherein floor () is a round-down operation.

Calculating a second counting value t from epoch J2000.0 (1 month, 1 day, 12 hours in 2000) to a given target time according to the julian day JD_c：

t_c＝(JD-2455197.5)×86400+315547200

(2.2) calculating a second counting value t from epoch J2000.0 (1 month, 1 day, 12 hours in 2000) to a given target time according to the step (2.1)_cAnd calculating a terrestrial rotation matrix ER, a nutation matrix NR and a precision matrix PR. The specific calculation method is explained below:

calculating a yellow meridian nutation delta psi, a yellow-red intersection angle and an intersection angle nutation delta:

wherein, T_2kRelative epoch J2000.0 (1 month, 1 day, 12 of 2000):

the earth rotation matrix ER calculation method comprises the following steps:

calculating the declination nutation delta mu:

Δμ＝Δψ*cos

calculating Greenwich mean time

Calculating greenwich mean time S_G：

Calculating an earth rotation matrix ER:

the nutation matrix NR calculation method comprises the following steps:

NR＝R_X(--Δ)R_Z(-Δψ)R_X()

wherein the content of the first and second substances,

the calculation method of the age matrix PR comprises the following steps:

calculating the age constant ζ_A、θ_A、Z_A：

Calculating a time offset matrix PR:

PR＝R_Z(-Z_A)R_Y(θ_A)R_Z(-ζ_A)

wherein the content of the first and second substances,

calculating a conversion matrix M from an inertia system to a ground-fixed system according to the earth rotation matrix ER, the nutation matrix NR and the precision matrix PR_ECI2ECF：

M_ECI2ECF＝ER*NR*PR

(2.3) t calculated according to the step (1)₁Position R of time satellite under inertial system_wECIAnd the transformation matrix M of the inertial system to the earth-fixed system calculated in the step (2.2)_ECI2ECFCalculating t₁Position R of time satellite under earth's fixed system_wECFThe obtained satellite position variation curve under the earth-fixed system is shown in fig. 6:

R_wECF＝M_ECI2ECF*R_wECI

(3) according to the longitude, latitude and elevation of the given ground measurement station antenna, the position R of the ground measurement station antenna under the ground fixation system is calculated_tECF. The specific calculation process is as follows:

calculating coordinate components G1 and G2 according to longitude lon, latitude lat and elevation h of the ground station antenna:

wherein f is the geometric oblateness of the earth ellipsoid, and f is 1/298.257.

Calculating the position R of the ground survey station antenna under the ground fixing system_tECF：

The calculation results are (unit is meter):

(4) t calculated according to the step (2)₁Position R of time satellite under earth's fixation_wECFAnd the position R of the ground survey station antenna calculated in the step (3) under the ground system_tECFCalculating t₁Position R of time satellite under the system of the center of the station_wCT。

The method comprises the following specific steps:

(4.1) under the station center system, calculating a conversion matrix M from the earth fixed system to the station center system_ECF2CTDescribed as the next rotation about the Z axis and one rotation about the X axis in the earth fixation system:

M_ECF2CT＝R_x(90°-lat)R_z(90°+lon)

wherein the content of the first and second substances,

(4.2) calculating according to the step (2)Obtained t₁Position R of time satellite under earth's fixation_wECFThe position R of the ground survey station antenna under the ground fixing system obtained by the calculation in the step (3)_tECFThe conversion matrix M from the earth fixation system to the station center system calculated in the step (4.1)_ECF2CTTranslating the origin of coordinates from the geocentric to the ground station antenna, and calculating t₁Position R of time satellite under the system of the center of the station_wCTNamely, the projection of the direction vector of the station antenna to the satellite under the station center system, and the obtained projection change curve of the direction vector of the station antenna to the satellite under the station center system is shown in fig. 7:

R_wCT＝M_ECF2CT*(R_wECF-R_tECF)

(5) calculating t according to the position of the satellite under the station center system calculated in the step (4)₁The antenna pointing guide angle of the ground survey station at the moment: high and low angleHorizontal angle psi. The specific calculation process is as follows:

assuming that the position of the ground survey station is located at the origin of the station center system, the projection of the antenna pointing vector of the survey station under the station center system is R_wCTRecord R_wCTComprises the following steps:

calculating elevation angle of antenna pointing guiding angleThe horizontal angle ψ is:

and according to x_CT、y_CT、z_CTPositive and negative of (2), angle of elevation

Dividing the horizontal angle psi into corresponding angle ranges to complete the antenna pointing guidance process:

in the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

Those skilled in the art will appreciate that, in addition to implementing the systems, apparatus, and individual modules thereof provided by the present invention in purely computer readable program code, the same procedures can be implemented entirely by logically programming method steps into logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Therefore, the system, the device and the modules thereof provided by the present invention can be considered as a hardware component, and the modules included in the system, the device and the modules thereof for implementing various programs can also be considered as structures in the hardware component; modules for performing various functions may also be considered to be both software programs for performing the methods and structures within hardware components.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.