An astronomical satellite integrated navigation and positioning system and method independent of horizontal reference and satellite signals

Abstract

The present invention relates to an astronomical satellite combined navigation and positioning system and method that does not rely on horizontal reference and satellite signals, characterized in that the system includes an observation system, an observation control system and a data processing system; the method includes: determining the position and altitude data of reference stars and satellites; obtaining the shooting trigger time, the trigger pulse interval and the number of trigger pulses, completing the shooting of star maps, latching the shooting time according to the time system information, and performing error correction on the observation data and the shooting time data; solving the corrected observation data to obtain the angular distance information between the reference star and the satellite at each time, and using the angular distance information to solve the right ascension value and declination value of the satellite in the second equatorial coordinate system relative to the observer at each time; solving the coordinate value of the observer's geocentric inertial coordinate system at each time. The present invention breaks through the traditional astronomical positioning theory, eliminates the direction and horizontal reference errors, has strong anti-interference, high positioning accuracy and realizes continuous positioning at all times.

Description

Technical Field

[0001] The invention relates to the technical field of celestial navigation and positioning, and in particular to a method for calculating the position of an observer by observing the right ascension and declination values ​​of a projection point of a satellite on the celestial sphere. Background Art

[0002] Astronomical navigation is a traditional positioning method. It uses natural celestial bodies with known accurate spatial positions as references, measures the positions of celestial bodies through relevant instruments, and determines the position information of the carrier where the measurement point is located through calculation. Astronomical navigation does not require the support of other ground equipment, so it has autonomous navigation characteristics, is not affected by artificial or naturally formed electromagnetic fields, does not radiate electromagnetic waves, has good concealment, and has relatively high positioning and orientation accuracy. Positioning errors do not accumulate over time. Therefore, today when satellite navigation is widely used, celestial navigation technology has been valued by countries around the world, especially major military powers, and is equipped on various carriers such as space-based, air-based, and sea-based.

[0003] Although the existing astronomical automatic navigation equipment is not exactly the same, they all use the height or azimuth of celestial bodies as the observation quantity, and their height and azimuth observations need to rely on the inertial platform to provide horizontal and directional references. At present, the horizontal accuracy of foreign inertial platforms is generally 20 to 40 arc seconds, and it is extremely difficult to further improve its accuracy. The resulting positioning theoretical error of the astronomical automatic navigation system is about 1,000 meters, which is not suitable for high-precision navigation in modern operations. The limitation of horizontal reference error has become a bottleneck for the development of astronomical navigation in the direction of high precision. Therefore, getting rid of the constraints of the horizontal reference, breaking through the traditional theoretical constraints with the height difference principle as the core content, and developing a new astronomical navigation theory system are the practical needs for achieving high-precision astronomical navigation.

[0004] Since the launch of the first artificial satellite in 1954, countries around the world have launched thousands of satellites into space. With the gradual implementation of Musk's Starlink plan, it is expected that the number of artificial satellites, especially low-Earth orbit satellites, will surge to tens of thousands in the next few years. These artificial celestial bodies provide new observable celestial bodies for astronomical navigation. Wang Anguo of the Dalian Naval Academy and Xuan Yang of the Central China Institute of Optoelectronics Technology have also proposed the use of radio to detect satellites, which provides new ideas for the development of astronomical navigation, but the traditional astronomical positioning theory is still continued.

[0005] In the early stages of the development of celestial navigation, scientists believed that using the angular distance of the moon to the stars to determine the position was the best solution. This idea is that if the celestial body is close to the earth, the position of the projection point of the celestial body observed by the observer on the celestial sphere is related to the observer's position, that is, when the observer's position on the earth's surface changes, the projection of the celestial body on the celestial sphere will change accordingly. If the accurate movement information of the celestial body is mastered, the observer's position can be solved. Among all natural celestial bodies, the moon is the closest to the earth. Therefore, in the early stages of development, scientists from various countries were exploring how to measure the angular distance between the moon and other stars. The establishment of the Greenwich Observatory and the invention of the sextant were directly or indirectly related to this plan. For the same purpose, Academician Euler of the Russian Academy of Sciences established the theory of lunar motion. In 1763, the Greenwich Observatory also compiled and published an almanac for determining longitude using the angular distance between the moon and the stars. However, in the subsequent development of the theory, it was found that the distance between the moon and the earth was too far relative to the radius of the earth, and the position of the observed projection point of the moon on the celestial sphere did not change much, so this plan was abandoned.

[0006] Currently, satellites can be accurately detected through optical, radio and other technical means. Abandoning the traditional idea of ​​measuring azimuth and altitude, positioning can also be achieved using the idea of ​​the angular distance between the moon and stars that was used hundreds of years ago. Moreover, since the distance between satellites and the earth is relatively close, more accurate positioning effects can be achieved. Summary of the invention

[0007] Aiming at the deficiencies of existing navigation means, the present invention provides an astronomical satellite combined navigation and positioning system and method which are independent of horizontal reference and satellite signals.

[0008] The basic principles of the technical solution of the present invention are as follows:

[0009] like Figure 1 As shown in the figure, in the geocentric inertial coordinate system, the center of the earth is the coordinate origin, the x-axis points to the vernal equinox, the z-axis points to the celestial north pole, and the y-axis is determined by the right-hand guide. This coordinate system is an inertial coordinate system, and the directions of each axis are fixed relative to the stars. Satellite positions generally use this coordinate system, and the coordinate values ​​are three-dimensional rectangular coordinates. Geographical locations generally use geographic coordinate systems, and the coordinate values ​​are expressed in longitude and latitude. However, in the fields of satellite navigation, satellite measurement and control, etc., it is often necessary to convert geographic coordinates into geocentric inertial coordinates for solution.

[0010] Assume that the observer is located somewhere on the surface of the earth, with geographic coordinates (λ, Ф), and a satellite is located on the observer's true horizon and can be observed, with coordinates of the geocentric inertial coordinate system (X, Y, Z). When the observer observes the satellite, what is observed is the projection point of the satellite on the celestial sphere. At this time, the coordinates of the satellite projection point can be expressed using the coordinate values ​​of the second equatorial coordinate system, namely, right ascension and declination. The angular distance between the satellite projection point and the star can be measured by optical, radio and other observation equipment, and the right ascension and declination values ​​of the satellite projection point can be solved using the basic principles of astronomical triangles.

[0011] In the geocentric inertial coordinate system, if the errors such as atmospheric refraction and aberration of light are not considered, the observer, satellite and the satellite's projection point on the celestial sphere are in a straight line. The satellite position and the coordinates of the satellite projection point on this straight line are known conditions. The satellite coordinates can be solved by the orbit equation, and the coordinates of the satellite projection point can be observed and solved. The intersection of this spatial straight line and the earth's surface is the observer's position.

[0012] Assume that the surveyor is on the sea surface, and his coordinates in the geocentric inertial coordinate system are (x, y, z). The coordinates satisfy the equation of the earth ellipsoid. The angle between the space vector determined by the surveyor, satellite and satellite projection point and the x-axis is α, and the angle between the space vector and the z-axis is δ. Similarly, two equations can be established to form a three-variable equation system. Solving this equation system can solve the coordinates of the surveyor in the geocentric inertial coordinate system, thereby determining the surveyor's position.

[0013] The existing astronomical automatic navigation theories all require the measurement of celestial bodies in the observer's horizon coordinate system. Since the horizon and directional references have errors that cannot be eliminated, the existing astronomical automatic navigation equipment has large positioning errors. The present invention uses the angular distance of satellites relative to other celestial bodies as the observation quantity. The observation quantity does not need to be based on the observer's true horizon, does not include horizontal reference and azimuth errors, and can be observed by optical, infrared, radio and other means. The angular distance measurement between the satellite projection point and the reference star can also obtain a measurement accuracy of arc seconds. Therefore, compared with the existing astronomical automatic navigation methods, the present invention can obtain higher measurement accuracy and has extremely high promotion and application value.

[0014] An astronomical satellite integrated navigation and positioning system that does not rely on horizontal references and satellite signals, which is special in that it includes an observation system, an observation control system and a data processing system;

[0015] The observation system is used for observing natural celestial bodies and satellites, and includes a horizon space stable observation platform carried on a ship, and star observation equipment and satellite observation equipment fixed on the horizon space stable observation platform;

[0016] The observation control system is used to control the observation system and celestial body identification and solution, and includes an observation control module, a star identification and solution module and a satellite identification and solution module;

[0017] The data processing system is mainly used for calculating the position of the surveyor, and includes an error correction module, a projection point calculation module and a position calculation module.

[0018] In one embodiment of the present invention, the horizontal space stable observation platform is fixed on the ship platform through a horizontal servo system, and the horizontal servo system controls the horizontal space stable observation platform to reach a horizontal stable state through the ship heading attitude information sent by the observation control system;

[0019] In one embodiment of the present invention, the star observation device is fixed to a stable observation platform in the horizontal space through a star observation servo system, and the star observation device is pointed to a predetermined spatial angle according to the azimuth and altitude angle sent by the observation control system to search and identify the predetermined star;

[0020] In one embodiment of the present invention, the satellite observation device is fixed to a stable observation platform in the horizontal space through a satellite observation servo system, and the satellite observation device is pointed to a predetermined spatial angle according to the azimuth and altitude angle sent by the observation control system to search and identify the predetermined satellite;

[0021] In one embodiment of the present invention, the star observation equipment and satellite observation equipment may be optical equipment, or infrared or radio detection equipment, and may be provided in one or more groups.

[0022] In one embodiment of the present invention, the observation control module includes a control data calculation module and a shooting control module. The control data calculation module is mainly used to calculate the azimuth and altitude of the selected stars and satellites, and send them together with the ship's heading attitude information to the observation system, which is used to stabilize the horizon space stable observation platform and provide observation guidance data for the observation equipment. The shooting control module is used to send the shooting trigger time, trigger pulse interval and trigger pulse number to the observation system. The observation system completes the star map shooting according to the instructions and latches the shooting time according to the time system information.

[0023] In one embodiment of the present invention, the star identification module includes a star catalog database and a star map matching module. The star catalog database is mainly used to store the position, motion, star and other data of natural celestial bodies. The star map matching module is mainly used to match and identify the star map taken by the star sensor or other observation equipment using the star map matching algorithm, and screen out the reference star for angular distance measurement.

[0024] In one embodiment of the present invention, the satellite identification module includes a satellite database and a satellite identification module. The satellite database module is used to store relevant data of all satellites in orbit and can update the satellite data through a communication system. The satellite identification module first calculates information such as satellite magnitude and angular velocity, and is used together with the star map matching module for satellite identification.

[0025] In one embodiment of the present invention, the error correction module is used to perform error correction on the detection data, including sensor internal error correction and external error correction. Internal errors are mainly caused by the deviation of various parameters from the nominal values, and are related to the specific structure of the sensor, and generally have specific correction methods. External errors usually refer to errors caused by factors other than the sensor itself when the sensor is in a normal working state. Internal errors mainly include camera assembly errors, thermal deformation errors, pixel resolution, etc. External errors mainly include atmospheric refraction and aberration of light, etc.

[0026] In one embodiment of the present invention, the projection point solution module includes a pseudo-azimuth height solution module, a celestial angular distance solution module and a right ascension and declination solution module. The pseudo-azimuth height solution module is used to solve the azimuth and altitude of the reference star and the satellite in the observation platform coordinate system. Although the observation data has been error corrected, it still contains the azimuth and horizontal reference errors of the observation platform. Therefore, the azimuth and altitude information measured in the observation platform coordinate system are called pseudo-azimuth and pseudo-altitude. The celestial angular distance module solves the angular distance between the satellite and the reference star based on the pseudo-azimuth and pseudo-altitude data of the reference star and the satellite. Since the pseudo-azimuth and pseudo-altitude data observed at the same time contain the same reference error, the solved celestial angular distance value can eliminate the platform reference error. The right ascension and declination solution module further solves the right ascension and declination of the satellite in the second equatorial coordinate system based on the angular distance between the satellite and the reference star.

[0027] In one embodiment of the present invention, the position solution module is used to solve the surveyor's longitude and latitude information, including a real-time position solution module and a smoothing filter module. The real-time position solution module establishes a line of sight equation based on the satellite right ascension and declination and the real-time position of the satellite, and together with the earth ellipsoid equation, forms an equation group. Solving the equation group can solve the three-dimensional coordinates in the surveyor's geocentric inertial coordinate system, and can be converted into longitude and latitude coordinates. The smoothing filter module performs smoothing filtering on the surveyor's position coordinates updated in real time, combined with the real-time estimated ship position, to obtain more accurate surveyor's longitude and latitude information.

[0028] Based on the above system, the present invention also proposes an astronomical satellite integrated navigation and positioning method that does not rely on horizontal references and satellite signals, which is special in that it includes:

[0029] Based on the acquired ship heading and attitude information, the system stabilizes the horizon space stable observation platform to a horizontal state;

[0030] Based on the acquired satellite orbit data, the system updates the satellite database of the satellite identification module in real time;

[0031] The system obtains the ship's estimated position data and time information, and combines the star catalog data and satellite data to select reference stars and satellites and determine the location and altitude data of the reference stars and satellites;

[0032] The star observation equipment and satellite observation equipment point to the reference star and satellite locations respectively. The star observation equipment captures the star map and completes the identification and tracking of the reference star through star map matching; the satellite observation equipment identifies and tracks the satellite.

[0033] The system obtains the shooting trigger time, trigger pulse interval and number of trigger pulses, completes the star map shooting according to the instructions, latches the shooting time according to the time system information, and performs error correction on the observation data and shooting time data;

[0034] The corrected observation data is solved to obtain the angular distance information between the reference star and the satellite at each moment, and the angular distance information between the reference star and the satellite is further used to solve the right ascension value and declination value of the satellite in the second equatorial coordinate system relative to the observer at each moment;

[0035] Based on the satellite right ascension and declination values ​​together with the earth ellipsoid equation, a set of equations is established to solve the coordinate values ​​of the observer's geocentric inertial coordinate system at each moment.

[0036] In one embodiment of the present invention, it also includes:

[0037] The final calculated coordinate values ​​of the surveyor's geocentric inertial coordinate system are smoothed and filtered to obtain more accurate surveyor position information.

[0038] In one embodiment of the present invention, the corrected observation data is solved to obtain the angular distance information between the reference star and the satellite at each moment. The specific solution process is as follows:

[0039] (1) According to the spherical triangle formula, assuming that the reference stars are two natural celestial bodies A and B, the angular distance between the two natural celestial bodies A and B is:

[0040]

[0041] where h′ A , h′ B is the pseudo-altitude angle of the two natural celestial bodies A and B in the horizontal coordinate system of the observation platform, A′ A , A′ B is the pseudo-azimuth of the two natural celestial bodies A and B in the horizontal coordinate system of the observation platform. In addition, the angular distance between the two natural celestial bodies A and B can also be calculated using the right ascension and declination values ​​in the aerospace astronomical almanac database:

[0042]

[0043] Among them, δ A ,δB is the declination value of two natural celestial bodies A and B, α A , α B is the right ascension value of two natural celestial bodies A and B.

[0044] (2) The angular distance between natural celestial body A and satellite S is:

[0045]

[0046] where h′ A , h′ s is the pseudo-elevation angle of the natural celestial body A and the satellite S in the horizontal coordinate system of the observation platform, A′ A , A′ S is the pseudo-azimuth of the natural celestial body A and the satellite S in the observation platform's horizontal coordinate system. Since the observation platform contains azimuth and horizontal reference errors, the azimuth and altitude in the observation platform's horizontal coordinate system are called pseudo-azimuth and pseudo-altitude.

[0047] (3) The angular distance between the natural celestial body B and the satellite S is:

[0048]

[0049] where h′ B , h′ s is the altitude angle of natural celestial body B and satellite S in the horizontal coordinate system of the observation platform, A′ B , A′ S is the azimuth of the natural celestial body B and the satellite S in the horizontal coordinate system of the observation platform.

[0050] In one embodiment of the present invention, the angular distance information between the reference star and the satellite is used to calculate the right ascension value and declination value of the satellite in the second equatorial coordinate system relative to the observer at each time. The specific calculation process includes:

[0051] (1) Solution of the spherical angle ∠PAB (P is the north celestial pole)

[0052] According to the spherical triangle formula

[0053]

[0054] in,

[0055]

[0056] (2) Solution of spherical angle ∠SAB

[0057]

[0058]

[0059] (3) Solution of spherical angle ∠PAS

[0060] ∠PAS=∠PAB-∠SAB

[0061] (4) Solution of ∠APS

[0062]

[0063]

[0064] (5) Satellite's apparent right ascension α S Solution

[0065] α S =α A +∠APS

[0066] (6) Satellite apparent declination δ S Solution

[0067]

[0068]

[0069]

[0070] In one embodiment of the present invention, the process of calculating the coordinate values ​​of the earth-centered inertial coordinate system of the observer at each moment is as follows:

[0071] (1) Solve the coordinates of the observer's geocentric inertial coordinate system

[0072] The observer coordinates satisfy the following equations

[0073]

[0074] Among them, x, y, z are the coordinates of the observer in the geocentric inertial coordinate system, X, Y, Z are the coordinates of the satellite in the geocentric inertial coordinate system, α S , δ S are the right ascension and declination values ​​of the satellite relative to the observer, a is the length of the major axis of the Earth ellipsoid, and b is the length of the minor axis of the Earth ellipsoid.

[0075] (2) Solve the latitude and longitude of the surveyor

[0076] Convert the surveyor's geocentric inertial coordinate system coordinates x, y, z into longitude and latitude coordinates λ and Φ.

[0077] The present invention discloses an astronomical satellite combined navigation and positioning system and method which is independent of horizontal reference and satellite signals, takes satellites with known accurate spatial positions and motion parameters as beacons, and calculates the observer's position by measuring the observed right ascension and declination values ​​of the satellite's projection point on the celestial sphere. The system and method can overcome the shortcomings of traditional astronomical positioning, such as limited observation opportunities, susceptibility of satellite navigation to interference, and expensive error accumulation of inertial navigation equipment, and provide ships with a new navigation system with strong anti-interference ability, accurate positioning, and more observation opportunities, which is an effective supplement to existing navigation means. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 This is a schematic diagram of the principle of an astronomical satellite integrated navigation and positioning system that does not rely on horizontal references and satellite signals according to the present invention;

[0079] Figure 2 This is a principle block diagram of an astronomical satellite integrated navigation and positioning system that does not rely on horizontal references and satellite signals as described in the present invention;

[0080] Figure 3 This is a composition diagram of an observation control system according to a first specific implementation mode of the present invention;

[0081] Figure 4 This is a composition diagram of an observation system according to a first specific implementation mode of the present invention;

[0082] Figure 5 It is a composition diagram of a data processing system for a specific implementation mode 1 of the present invention;

[0083] Figure 6 This is a system workflow diagram for a specific implementation mode 1 of the present invention;

[0084] Figure 7 Schematic diagram of celestial coordinates and data solution process. Example

[0085] The present embodiment is an astronomical satellite integrated navigation and positioning system that does not rely on horizontal reference and satellite signals, such as Figures 2 to 6 As shown, the system mainly includes an observation system, an observation control system and a data processing system; the data received by the system includes ship heading attitude information, ship estimated position, time system information and satellite orbit data;

[0086] The observation system is mainly used for observing natural celestial bodies and satellites, including a stable horizon space observation platform carried on a ship, and star observation equipment and satellite observation equipment fixed on the stable horizon space observation platform.

[0087] The horizon space stable observation platform is fixed on the ship platform through a horizon servo system, and the horizon servo system controls the horizon space stable observation platform to reach a horizontal stable state through the ship heading attitude information sent by the observation control system.

[0088] The star observation device is fixed to a stable observation platform in the horizontal space through a star observation servo system. The star observation device is pointed to a predetermined spatial angle according to the azimuth and altitude angle sent by the observation control system to search and identify the predetermined star.

[0089] The satellite observation device is fixed to a stable observation platform in the horizontal space through a satellite observation servo system. The satellite observation device is directed to a predetermined spatial angle according to the azimuth and altitude angle sent by the observation control system to search and identify the predetermined satellite.

[0090] The star observation equipment and satellite observation equipment can be optical equipment, or infrared or radio detection equipment, and can be set in one or more groups. In order to ensure the satellite observation capability, when using optical means, a high-magnification astronomical telescope should be used.

[0091] The observation control system is mainly used to control the observation system and celestial body identification and solution, and includes an observation control module, a star identification and solution module and a satellite identification and solution module.

[0092] The observation control module includes a control data calculation module and a shooting control module. The control data calculation module is mainly used to calculate the azimuth and altitude of the selected stars and satellites, and send them together with the ship's heading attitude information to the observation system, which is used to stabilize the horizon space stable observation platform and provide observation guidance data for the observation equipment. The shooting control module is used to send the shooting trigger time, trigger pulse interval and trigger pulse number to the observation system. The observation system completes the star map shooting according to the instructions and latches the shooting time according to the time system information.

[0093] The star identification module includes a star catalog database and a star map matching module. The star catalog database is mainly used to store the position, motion, star and other data of natural celestial bodies. The star map matching module is mainly used to match and identify the star maps taken by the star sensor or other observation equipment using the star map matching algorithm, and select the reference stars for angular distance measurement.

[0094] The satellite identification module includes a satellite database and a satellite identification module. The satellite database module is used to store the relevant data of all satellites in orbit and can update the satellite data through the communication system. The satellite identification module first calculates the satellite magnitude, angular velocity and other information, and is used together with the star map matching module for satellite identification.

[0095] The data processing system is mainly used for calculating the position of the surveyor, and includes an error correction module, a projection point calculation module and a position calculation module.

[0096] The error correction module is used to correct the detection data, including sensor internal error correction and external error correction. Internal errors are mainly caused by the deviation of various parameters from the nominal values, and are related to the specific structure of the sensor. Generally, there are specific correction methods. External errors usually refer to errors caused by factors other than the sensor itself when the sensor is in normal working state. Internal errors mainly include camera assembly errors, thermal deformation errors, pixel resolution, etc. External errors mainly include atmospheric refraction and aberration of light, etc.

[0097] The projection point solution module includes a pseudo-azimuth height solution module, a celestial body angular distance solution module and a right ascension and declination solution module. The pseudo-azimuth height solution module is used to solve the azimuth and altitude of the reference star and the satellite in the observation platform coordinate system. Although the observation data has been error corrected, it still contains the azimuth and horizontal reference errors of the observation platform. Therefore, the azimuth and altitude information measured in the observation platform coordinate system are called pseudo-azimuth and pseudo-altitude. The celestial body angular distance module solves the angular distance between the satellite and the reference star based on the pseudo-azimuth and pseudo-altitude data of the reference star and the satellite. Since the pseudo-azimuth and pseudo-altitude data observed at the same time contain the same reference error, the solved celestial body angular distance value can eliminate the platform reference error. The right ascension and declination solution module further solves the right ascension and declination of the satellite in the second equatorial coordinate system based on the angular distance between the satellite and the reference star.

[0098] The position solving module is used to solve the surveyor's longitude and latitude information, including a real-time position solving module and a smoothing filter module. The real-time position solving module establishes a line of sight equation based on the satellite right ascension and declination and the real-time position of the satellite, and together with the earth ellipsoid equation, forms an equation group. Solving the equation group can solve the three-dimensional coordinates in the surveyor's geocentric inertial coordinate system, and can be converted into longitude and latitude coordinates. The smoothing filter module performs smoothing filtering on the surveyor's position coordinates updated in real time, combined with the real-time estimated ship position, to obtain more accurate surveyor's longitude and latitude information.

[0099] The navigation and positioning system of this embodiment, its workflow, i.e., the positioning method, is referred to as Figure 6 As shown, including:

[0100] 1. The observation control system obtains the ship's heading and attitude information. After the observation control module calculates the servo data, it is sent to the observation platform module of the observation system. The observation platform servo system of the observation platform module starts working to control the horizontal space stable observation platform to maintain a horizontal and stable state;

[0101] 2. The observation and control system obtains satellite orbit data and updates the satellite database of the satellite identification module in real time;

[0102] 3. The observation and control system obtains the ship position estimation data and time information respectively, combines the star catalog database under the star identification module and the satellite database under the satellite identification module, selects reference stars and satellites, calculates the azimuth and altitude data of the reference stars and satellites, and sends them to the observation system;

[0103] 4. The observation system receives the azimuth and altitude data of the reference star and the satellite, and the star observation servo system and the satellite observation servo system respectively drive the star observation equipment and the satellite observation equipment to point to the space area where the reference star and the satellite are located;

[0104] 5. The star observation equipment takes star maps and matches them to identify and track reference stars; the satellite observation equipment searches for satellites to identify and track them;

[0105] 6. After both the star observation equipment and the satellite observation equipment have completed the identification and tracking of the reference star and the satellite, the shooting control module of the observation control system sends the shooting trigger time, the trigger pulse interval and the number of trigger pulses to the observation system;

[0106] 7. The observation system completes the star map shooting according to the instructions, locks the shooting time according to the time system information, and sends the observation data and shooting time data to the data processing system;

[0107] 8. The error correction module of the data processing system corrects the internal and external errors of the sensor of the observed data respectively;

[0108] 9. The pseudo-azimuth height calculation module calculates the observation data after error correction, and obtains the angular distance information between the reference star and the satellite at each moment according to the pseudo-horizontal coordinate value;

[0109] The solution process includes:

[0110] (1) According to the spherical triangle formula, assuming that the reference stars are two natural celestial bodies A and B, the angular distance between the two natural celestial bodies A and B is:

[0111]

[0112] where h′ A , h′ B is the pseudo-altitude angle of the two natural celestial bodies A and B in the horizontal coordinate system of the observation platform, A′ A , A′ B is the pseudo-azimuth of the two natural celestial bodies A and B in the horizontal coordinate system of the observation platform. In addition, the angular distance between the two natural celestial bodies A and B can also be calculated using the right ascension and declination values ​​in the aerospace astronomical almanac database:

[0113]

[0114] Among them, δA ,δ B is the declination value of two natural celestial bodies A and B, α A , α B is the right ascension value of two natural celestial bodies A and B.

[0115] (2) The angular distance between natural celestial body A and satellite S is:

[0116]

[0117] where h′ A , h′ s is the pseudo-elevation angle of the natural celestial body A and the satellite S in the horizontal coordinate system of the observation platform, A′ A , A′ S is the pseudo-azimuth of the natural celestial body A and the satellite S in the observation platform's horizontal coordinate system. Since the observation platform contains azimuth and horizontal reference errors, the azimuth and altitude in the observation platform's horizontal coordinate system are called pseudo-azimuth and pseudo-altitude.

[0118] (3) The angular distance between the natural celestial body B and the satellite S is:

[0119]

[0120] where h′ B , h′ s is the altitude angle of natural celestial body B and satellite S in the horizontal coordinate system of the observation platform, A′ B , A′ S is the azimuth of the natural celestial body B and the satellite S in the horizontal coordinate system of the observation platform.

[0121] 10. The right ascension and declination module uses the angular distance information between the reference star and the satellite to calculate the right ascension and declination values ​​of the satellite in the second equatorial coordinate system at each moment relative to the observer;

[0122] The solution process is:

[0123] (1) Solution of the spherical angle ∠PAB (P is the north celestial pole)

[0124] According to the spherical triangle formula

[0125]

[0126] in,

[0127]

[0128] (2) Solution of spherical angle ∠SAB

[0129]

[0130]

[0131] (3) Solution of spherical angle ∠PAS

[0132] ∠PAS=∠PAB-∠SAB

[0133] (4) Solution of ∠APS

[0134]

[0135]

[0136] (5) Satellite's apparent right ascension α S Solution

[0137] α S =α A +∠APS

[0138] (6) Satellite apparent declination δ S Solution

[0139]

[0140]

[0141]

[0142] 11. The position calculation module receives the satellite right ascension and declination values, and establishes a set of equations together with the earth ellipsoid equation to calculate the coordinate values ​​of the earth-centered inertial coordinate system of the observer at each moment;

[0143] The solution process is:

[0144] (1) Solve the coordinates of the observer's geocentric inertial coordinate system

[0145] The observer coordinates satisfy the following equations

[0146]

[0147] Among them, x, y, z are the coordinates of the observer in the geocentric inertial coordinate system, X, Y, Z are the coordinates of the satellite in the geocentric inertial coordinate system, α S ,δ S are the right ascension and declination values ​​of the satellite relative to the observer, a is the length of the major axis of the Earth ellipsoid, and b is the length of the minor axis of the Earth ellipsoid.

[0148] (3) Solve the latitude and longitude of the surveyor

[0149] Convert the surveyor's geocentric inertial coordinate system coordinates x, y, z into longitude and latitude coordinates λ and Φ.

[0150] 12. The smoothing filter module performs smoothing filtering on the position of the observer at each moment to obtain more accurate observer position information.

[0151] Beneficial effects of the present invention:

[0152] 1. Break through the traditional astronomical positioning theory and eliminate the direction and horizontal reference errors. The traditional astronomical positioning theory needs to rely on the direction or horizontal reference to obtain the azimuth and altitude information of the celestial body. The direction and horizontal reference errors cannot be eliminated, resulting in poor positioning accuracy. The observation quantity based on the present invention is the angular distance between the satellite and other celestial bodies, which does not contain the direction and horizontal reference errors, so it can greatly improve the positioning accuracy.

[0153] 2. An observation method that does not rely on a horizontal reference platform can be developed. Although the present invention still uses a horizontal reference platform for observation, it is only for the purpose of completing the search for celestial bodies, and the error requirements for the platform are greatly reduced. Subsequently, a star map matching algorithm that does not require a stable observation platform can be developed, which does not rely on azimuth and altitude information to complete star map matching, and directly measures the angular distance between the satellite and the reference star to complete positioning. Existing astronomical automatic navigation equipment all requires inertial navigation to provide a stable observation platform, and inertial navigation equipment is expensive. If it can be separated from the horizontal reference platform to complete detection and positioning, the system cost can be greatly reduced.

[0154] 3. Strong anti-interference ability. If the satellite orbit data in the satellite database is relatively accurate, positioning can be completed autonomously without relying on external information. If the satellite data is inaccurate, the base needs to send satellite orbit update data to the ship, and the comprehensive anti-interference ability of various communication means of the ship is much stronger than satellite navigation.

[0155] 4. High positioning accuracy. The present invention is completely unaffected by horizontal and azimuth reference errors, and the optical and other detection means have high angle measurement accuracy, so it has higher positioning accuracy than existing astronomical automatic navigation equipment.

[0156] 5. Continuous positioning can be achieved at all times. Due to the large number of available satellites and the comprehensive use of optical, infrared, radio and other detection methods, continuous positioning can be achieved at all times under good weather conditions.

Claims

1. An astronomical satellite integrated navigation and positioning system that does not rely on horizontal reference and satellite signals, characterized in that: Including observation system, observation control system and data processing system; The observation system is used for observing natural celestial bodies and satellites, and includes a horizon space stable observation platform carried on a ship, and star observation equipment and satellite observation equipment fixed on the horizon space stable observation platform; The observation control system is used to control the observation system and celestial body identification and solution, and includes an observation control module, a star identification and solution module and a satellite identification and solution module; The data processing system is mainly used for calculating the position of the surveyor, including an error correction module, a projection point calculation module and a position calculation module; wherein, The error correction module is used to perform error correction on the detection data, including sensor internal error correction and external error correction; the internal error includes camera assembly error, thermal deformation error and pixel resolution, while the external error includes atmospheric refraction and aberration; The projection point calculation module includes a pseudo-azimuth height calculation module, a celestial body angular distance calculation module and a right ascension and declination calculation module; the pseudo-azimuth height calculation module is used to calculate the azimuth and altitude of the reference star and the satellite in the observation platform coordinate system; the celestial body angular distance module calculates the angular distance between the satellite and the reference star according to the pseudo-azimuth and pseudo-altitude data of the reference star and the satellite, and the right ascension and declination calculation module further calculates the right ascension and declination of the satellite in the second equatorial coordinate system according to the angular distance between the satellite and the reference star; The position solving module is used to solve the surveyor's longitude and latitude information, including a real-time position solving module and a smoothing filtering module; the real-time position solving module establishes a line of sight equation according to the satellite right ascension and declination and the satellite's real-time position, and together with the earth ellipsoid equation, forms an equation group, and solving the equation group can solve the surveyor's three-dimensional coordinates in the geocentric inertial coordinate system, and can be converted into longitude and latitude coordinates; the smoothing filtering module performs smoothing filtering on the surveyor's position coordinates updated in real time, combined with the real-time calculated ship position, to obtain more accurate surveyor's longitude and latitude information.

2. The astronomical satellite integrated navigation and positioning system that does not rely on horizontal reference and satellite signals as claimed in claim 1, characterized in that: The horizontal space stable observation platform is fixed on the ship platform through a horizontal servo system, and the horizontal servo system controls the horizontal space stable observation platform to reach a horizontal stable state through the ship heading attitude information sent by the observation control system; The star observation device is fixed to the stable observation platform in the horizontal space through the star observation servo system, and the star observation device is pointed to a predetermined spatial angle according to the azimuth and altitude angle sent by the observation control system to search and identify the predetermined star; The satellite observation device is fixed to the stable observation platform in the horizontal space through the satellite observation servo system, and the satellite observation device is pointed to the predetermined spatial angle according to the azimuth and altitude angle sent by the observation control system to search and identify the predetermined satellite; The star observation equipment and satellite observation equipment are arranged in one or more groups, which use optical equipment or infrared / radio detection equipment.

3. The astronomical satellite integrated navigation and positioning system that does not rely on horizontal reference and satellite signals as claimed in claim 1, characterized in that: The observation control module includes a control data calculation module and a shooting control module; the control data calculation module is used to calculate the azimuth and altitude of the selected stars and satellites, and send them together with the ship's heading attitude information to the observation system, which is used to stabilize the horizon space stable observation platform and provide observation guidance data for the observation equipment; the shooting control module is used to send the shooting trigger time, trigger pulse interval and trigger pulse number to the observation system, and the observation system completes the star map shooting according to the instructions, and latches the shooting time according to the time system information; The star identification and solution module includes a star catalog database and a star map matching module; the star catalog database is used to store the position, movement and star data of natural celestial bodies; the star map matching module is used to match and identify the star map taken by the star sensor or other observation equipment using the star map matching algorithm, and screen out the reference star for angular distance measurement; The satellite identification and solution module includes a satellite database and a satellite identification module; the satellite database module is used to store relevant data of all on-orbit satellites and can update the satellite data through the communication system; the satellite identification module first calculates the satellite magnitude and angular velocity information, and is used together with the star map matching module for satellite identification.

4. An astronomical satellite integrated navigation and positioning method based on the system according to any one of claims 1 to 3 that does not rely on horizontal references and satellite signals, characterized in that: include: Based on the acquired ship heading and attitude information, the system stabilizes the horizon space stable observation platform to a horizontal state; Based on the acquired satellite orbit data, the system updates the satellite database of the satellite identification module in real time; The system obtains the ship's estimated position data and time information, and combines the star catalog data and satellite data to select reference stars and satellites and determine the location and altitude data of the reference stars and satellites; The star observation device and the satellite observation device point to the reference star and the satellite respectively. The star observation device captures the star map and completes the identification and tracking of the reference star through star map matching. Satellite observation equipment identifies and tracks satellites; The system obtains the shooting trigger time, trigger pulse interval and number of trigger pulses, completes the star map shooting according to the instructions, latches the shooting time according to the time system information, and performs error correction on the observation data and shooting time data; The corrected observation data is solved to obtain the angular distance information between the reference star and the satellite at each moment, and the angular distance information between the reference star and the satellite is further used to solve the right ascension value and declination value of the satellite in the second equatorial coordinate system relative to the observer at each moment; Based on the satellite right ascension and declination values ​​together with the earth ellipsoid equation, a set of equations is established to solve the coordinate values ​​of the observer's geocentric inertial coordinate system at each moment.

5. The astronomical satellite integrated navigation and positioning method according to claim 4, which is independent of horizontal reference and satellite signals, is characterized in that: Also includes: The final calculated coordinate values ​​of the surveyor's geocentric inertial coordinate system are smoothed and filtered to obtain more accurate surveyor position information.

6. The astronomical satellite integrated navigation and positioning method according to claim 4, which is independent of horizontal reference and satellite signals, is characterized in that: The corrected observation data is solved to obtain the angular distance information between the reference star and the satellite at each moment. The specific solution process is as follows: (1) According to the spherical triangle formula, assuming that the reference stars are two natural celestial bodies A and B, the angular distance between the two natural celestial bodies A and B is: where h′ A , h′ B is the pseudo-altitude angle of the two natural celestial bodies A and B in the horizontal coordinate system of the observation platform, A′ A , A′ B is the pseudo-azimuth of the two natural celestial bodies A and B in the horizontal coordinate system of the observation platform. In addition, the angular distance between the two natural celestial bodies A and B is also calculated using the right ascension and declination values ​​in the aerospace astronomical almanac database: Among them, δ A , δ B is the declination value of two natural celestial bodies A and B, α A , α B are the right ascension values ​​of two natural celestial bodies A and B; (2) The angular distance between natural celestial body A and satellite S is: where h′ A , h′ s is the pseudo-elevation angle of the natural celestial body A and the satellite S in the horizontal coordinate system of the observation platform, A′ A , A′ S is the pseudo-azimuth of the natural celestial body A and the satellite S in the observation platform's horizontal coordinate system; since the observation platform contains azimuth and horizontal reference errors, the azimuth and altitude in the observation platform's horizontal coordinate system are called pseudo-azimuth and pseudo-altitude; (3) The angular distance between the natural celestial body B and the satellite S is: where h′ B , h′ s is the altitude angle of natural celestial body B and satellite S in the horizontal coordinate system of the observation platform, A′ B , A′ S is the azimuth of the natural celestial body B and the satellite S in the horizontal coordinate system of the observation platform.

7. The astronomical satellite integrated navigation and positioning method that does not rely on horizontal reference and satellite signals as claimed in claim 6, characterized in that: The angular distance information between the reference star and the satellite is used to calculate the right ascension value and declination value of the satellite relative to the observer at each moment in the second equatorial coordinate system. The specific calculation process includes: (1) Solution of the spherical angle ∠PAB, where P is the north celestial pole According to the spherical triangle formula in, (2) Solution of spherical angle ∠SAB (3) Solution of spherical angle ∠PAS ∠PAS=∠PAB-∠SAB (4) Solution of ∠APS (5) Satellite's apparent right ascension α S Solution a S =a A +∠APS (6) Satellite apparent declination δ S Solution 8. The astronomical satellite integrated navigation and positioning method according to claim 4, which is independent of horizontal reference and satellite signals, is characterized in that: The calculation process of the coordinate values ​​of the earth-centered inertial coordinate system of the observer at each moment is as follows: (1) Solve the coordinates of the observer's geocentric inertial coordinate system The observer coordinates satisfy the following equations Among them, x, y, z are the coordinates of the observer in the geocentric inertial coordinate system, X, Y, Z are the coordinates of the satellite in the geocentric inertial coordinate system, α S , δ S is the right ascension and declination of the satellite relative to the observer, a is the length of the major axis of the Earth ellipsoid, and b is the length of the minor axis of the Earth ellipsoid; (2) Solve the latitude and longitude of the surveyor Convert the surveyor's geocentric inertial coordinate system coordinates x, y, z into longitude and latitude coordinates λ and Φ.

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