RU2797443C1 - Method for constructing an optimal satellite communication system for pointing an aircraft at a moving surface object - Google Patents

Abstract

FIELD: radio communications.

SUBSTANCE: this technical solution is primarily intended to build an optimal satellite communication system for guiding an aircraft to a mobile surface object in the conditions where the initial location, direction and speed of movement are random. The invention suggests optimizing the orbital structure of a group of spacecraft by dividing the zone of the possible position of a mobile surface object into sectors and determining, taking into account the characteristics of the aircraft, the surface object and the transmitted control signals, the optimal parameters of the orbits using one of the statistical test methods by simulation modelling.

EFFECT: maximizing the possibility of bringing information to the aircraft when pointing it at a moving surface object by determining the optimal parameters of the grouping orbits of communication spacecraft, taking into account the signal-code design used and the parameters of the transmitted messages.

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Description

The invention relates to the field of radio communications using relay satellites.

This technical solution is primarily intended to build an optimal satellite communication system in the interests of guiding an aircraft to a mobile object (in particular, surface) in conditions where the initial location, direction and speed of movement are random.

The current level of development of rocket and space technology involves the presence of spacecraft in orbit, including communication satellites, which have the ability to change the orbit depending on the tasks that arise. The orbit can be modified by sending an additional pulse to the communication satellite. For example, the speed of a communications satellite can be changed by briefly switching on a maneuvering rocket engine, having previously oriented the satellite in such a way as to obtain a given result.

In such conditions, objectively there is a problem of optimal distribution of communication satellites in space to achieve the maximum effect within the framework of the problem being solved.

If we consider the practice of launching modern communication satellites into orbit, which involves the simultaneous launch of, for example, a cluster launch of about 100 satellites or more, then the task of optimizing their relative position for a specific problem being solved arises naturally.

In the proposed invention, changing the parameters of the orbits is understood as the maneuvering of satellites of an existing constellation, and the formation of a new constellation, taking into account the optimal parameters.

One of the tasks that have to be solved using satellite communications is the control of aircraft, which in the context of the present invention include unmanned aerial vehicles and guided missiles.

The task of control becomes more complicated when, due to the technical features of satellites and aircraft, it is not possible to ensure continuous communication. Such difficulties may be due to the energy, functional and hardware capabilities of satellites and aircraft, terrain, the presence of a plasma trail when moving at high speeds, weather phenomena and other factors. The process of transmission of control messages is quite complex and multifactorial.

The task of controlling an aircraft becomes even more difficult when the destination is not known exactly. That is, the object on which guidance is carried out can have random coordinates. Such an object can be an iceberg, in the direction of which a controlled flight of an unmanned aerial vehicle or a missile must be made to destroy a given target. Another example is a drifting laboratory or ship to which equipment or supplies must be delivered by means of an unmanned aerial vehicle.

In the context of the proposed method, a moving surface object has random coordinates and a random change in direction of movement. At the same time, it should be possible to point an aircraft at it using a constellation of a satellite communication system.

The main idea of the method lies in the fact that the orbital construction of the spacecraft constellation is optimized by dividing the zone of the possible position of the mobile surface object into sectors and determining, taking into account the characteristics of the aircraft, the surface object and the transmitted control signals, the optimal parameters of the orbits using one of the statistical test methods (brute force, Monte Carlo) in the framework of simulation modeling.

Known invention "Optimization of the system using the formation of the antenna pattern" (patent RU No. 2265956, 2003).

The essence of this invention is as follows.

A method for increasing system throughput in a satellite communication system (as an integral part of an analogue invention) containing a plurality of communication satellites, in which the satellite contains an antenna array and an antenna beamformer for creating a plurality of beams, which consists in the following: determining the location of the said satellite with using latitude, which is an angular distance measured in degrees from the equator; generating a plurality of beams based on said location; identifying a first beam in said plurality of beams; determining whether a direction change of the first beam is required based on the location of said satellite; determining whether a change in the cell size is required for said first beam, and changing the diameter of the cell to effect said change in the cell size, characterized in that: further determining whether a change in the beam pointing angle is required for said first beam; changing the distance between the centers of the honeycomb cells to carry out said change in the angle of pointing the beam; further determining whether a change in cell size is required for said first beam, and changing the minor axis of the cell to effect said change in cell size; further determining whether a beam pointing angle change is required for said first beam, and changing the distance between the focal points of the cells to effect said beam pointing angle change; further identifying a second beam in said plurality of beams, and determining whether a change in the second beam is required based on the location of said satellite; further identifying a second beam in said plurality of beams, identifying a location of a second cell associated with the second beam, and determining whether a second beam needs to be changed based on the satellite location and the location of the second cell; further identifying a location of a first cell associated with said first beam, and determining if a change in the first beam is required based on the location of the satellite and the location of the first cell; further identifying a location of a first cell associated with said first beam, and determining if a change in the first beam is required based on the satellite location and the time of day at that satellite location; further identifying a first beam group in said plurality of beams and determining whether a change in the first beam group is required based on the location of said satellite; further identifying a first beam group in said beam set, identifying a location of a first group of cells associated with the first beam group, and determining whether a change in the first beam group is required based on the location of the satellite and the location of the first group of cells; further identifying a second group of beams in said plurality of beams, identifying a location of a second group of cells associated with said second group of beams, and determining whether a second beam group needs to be changed based on the location of the satellite and the location of the second group of cells; the first beam group and the second beam group are identified using a table stored on the satellite, said table providing information on at least cell sizes and beam pointing angles; the first beam group and the second beam group are identified using annular cell groups; the first beam group and the second beam group are identified using rows of cells; further determining whether cell size changes are required for said first group of cells, changing cell diameters to effect said cell size changes, determining whether changes in beam pointing angles are required for said first group of beams, and changing distances between cell centers for making said beam pointing angle changes; further determining whether changes in cell sizes are required for said first group of cells, changing the minor axes of the cells to effect said changes in cell sizes, determining whether changes in beam pointing angles are required for said first group of beams, and changing the distances between the focal points of the cells cells for carrying out said changes in beam pointing angles; further identifying a second group of beams in said plurality of beams, identifying a location of a second group of cells associated with the second group of beams, and determining whether changes to the second beam group are required based on the location of the satellite and the operating state of the first beam group.

The analogue method has the following disadvantages.

1. Do not provide optimization of spacecraft constellation.

2. They do not maximize the possibility of bringing information to an aircraft moving towards a moving surface target.

3. Simulation modeling is not used to evaluate the effectiveness of all possible options for constructing a satellite communication system within the allowable values of variable parameters.

The analogue method does not allow to determine the optimal orbit parameters for the existing set of communication satellites when solving the problem of guiding an aircraft to a mobile surface object using this grouping to bring control signals.

Known "Method for managing multipath coverage of the service area in a satellite system using satellite relays in a highly elliptical orbit" (patent RU No. 2522715, 2014).

The essence of this invention is as follows.

A method for managing multipath coverage of a service area in a satellite system using relay satellites in a highly elliptical orbit equipped with a multibeam antenna for communication with earth stations during the period the relay satellite is above the service area of the indicated stations, in which a multipath coverage of the service area is formed on the relay satellite , during the movement of the relay satellite in orbit, they record data on the aiming points of the beams of the multibeam antenna and their zones, and also store data on the service area, characterized in that the angular size of the coverage area of the multibeam antenna is set not less than the angular size of the service area in the widest its part, visible at the time the satellite-relay is at the beginning or end of the working section of the highly elliptical orbit, during the movement of the satellite-relay along the working section of the highly elliptical orbit, the direction of the axis of the central beam of the multibeam antenna to the center of the service area is determined at the beginning of the working section of the highly elliptical orbit on Based on the data on the antenna beams and the service area stored on board the relay satellite, the active beams, the zones of which overlap with the service area, and the passive beams, the zones of which do not overlap with the service area, connect the active beams to the onboard transceiver equipment, periodically monitor the coincidence of the beam zones with a service area, according to the results of the specified control, those active beams are disconnected from the onboard transceiver equipment, the zones of which do not overlap with the service area, and those passive beams, the zones of which overlap with the service area, are connected to the onboard transceiver equipment.

The analogue method has the following disadvantages.

1. Maximizes coverage area with satellite beam steering alone.

2. They do not maximize the quality of communication for the entire route of the subscriber.

3. They do not provide optimization of the spacecraft constellation.

4. Do not maximize the possibility of bringing information to an aircraft moving towards a moving surface target.

5. Simulation modeling is not used to evaluate the effectiveness of all possible options for constructing a satellite communication system within the allowable values of variable parameters.

The analogue does not allow to determine the parameters of the satellite communication system, which will be optimal for a communication session with an aircraft moving towards a moving surface target, the location and speed of which are not exactly known.

The closest in technical essence to the claimed method and selected as a prototype is the "Method for constructing a space relay and communication system" (patent RU No. 2 755019, 2021).

The essence of this invention is as follows.

A method for constructing a space relay and communication system, in which information exchange between low-energy terrestrial and space subscribers and central earth stations is carried out through relay satellites in highly elliptical orbits containing multibeam antennas, characterized in that , at least two relay satellites in geostationary orbit, the angular separation between which is set close to 180 °, each relay satellite in geostationary orbit is equipped with steerable antennas of the radio frequency or optical range, with the help of which information is exchanged with high-energy space subscribers, satellites - repeaters in highly elliptical and geostationary orbit are equipped with retargetable antennas for communication between relay satellites in highly elliptical and geostationary orbits, with the help of which information exchange is carried out between low-energy space and terrestrial subscribers and central earth stations during the period when relay satellites are in highly elliptical orbit outside the visibility zone of central earth stations, on all relay satellites carry out current control of the spatial position of communication lines between relay satellites in highly elliptical and geostationary orbits, select the specified communication line with the shortest length and exclude information exchange over it during its eclipse by the Earth or the adjacent atmospheric layer.

The prototype method has the following disadvantages.

1. Adapt the satellite communication system to the current conditions by controlling the parameters of the radiation, and not the parameters of the orbits.

2. They do not maximize the quality of communication for the entire route of the subscriber.

3. They do not provide optimization of the spacecraft constellation.

4. Do not maximize the possibility of bringing information to an aircraft moving towards a moving surface target.

5. Simulation modeling is not used to evaluate the effectiveness of all possible options for constructing a satellite communication system within the allowable values of variable parameters.

The prototype does not allow you to determine the parameters of the constellation of a satellite communication system that will be optimal for a communication session with an aircraft moving towards a moving surface target, the location and speed of which are not exactly known.

The technical result of the proposed method consists in maximizing the integral coefficient of bringing information to the aircraft when pointing it at a moving surface object, by determining, using simulation modeling, the optimal parameters of the orbits of the constellation of communication spacecraft, taking into account the signal-code design used and the parameters of the transmitted messages.

The problem that the proposed method solves is to build an optimal satellite communication system for guiding an aircraft to a mobile surface object, while: setting the initial parameters of the spacecraft constellation in the form of Keplerian orbital parameters for the available communication satellites; set the parameters of the transmitted messages, including the frequency of repetition of the message, the amount of the message, the data rate and the rate of error-correcting coding; set the initial conditions for modeling the constellation in the form of the location of spacecraft in space; set the launch site of the aircraft, the trajectory of its movement; set the possible location and speed of movement of the surface object; dividing the zone of possible location of a mobile surface object into sectors with a size depending on the speed of the aircraft, the distance to the zone and the speed of the surface object; sorting through the method of statistical tests grouping parameters by rotating the orbits of spacecraft around the center of mass of the Earth in three planes; determine by means of simulation the probability of delivering a message during the movement of the aircraft to each sector of the zone of the possible presence of a surface object for all possible angles of rotation of the orbits of the constellation of communication spacecraft; determine the integral coefficient of the possibility of bringing information to the aircraft during its movement for the entire zone of possible location of the surface object as the arithmetic mean of the probabilities of bringing the message when moving to each sector from the partition zone; choose the option of constructing the orbital constellation of the satellite communication system with the maximum integral coefficient of the possibility of bringing; form a constellation taking into account the optimal parameters by adjusting the orbits of the spacecraft.

The operation of the invention is illustrated by the following graphics:

Fig. 1 is a functional diagram of a method for constructing an optimal satellite communication system for pointing an aircraft at a moving surface object.

To solve this problem, a method is proposed for constructing an optimal satellite communication system for pointing an aircraft at a moving surface object, which consists in the following:

set the initial parameters of the constellation of spacecraft in the form of Keplerian parameters of the orbits for the available communication satellites and enter them into block 1 of the initial data of the constellation;

set the parameters of the transmitted messages, including the repetition rate of the message, the size of the message, the data rate and the rate of error-correcting coding and enter them in block 2 of the original data of the transmitted message;

set the initial conditions for modeling the constellation in the form of the location of the spacecraft in space and enter them into block 3 of the initial conditions of the simulation;

set the launch site of the aircraft, the trajectory of its movement and enter them into block 4 of the initial data of the aircraft;

set the possible location and speed of the surface object and enter them into block 5 of the source data of the surface object;

transmitting the initial data of the aircraft from block 4 and the initial data of the surface object from block 5 to block 6 dividing the possible location area of the mobile surface object into sectors;

dividing the zone of possible location of a mobile surface object into sectors with a size depending on the speed of the aircraft, the distance to the zone and the speed of the surface object in block 6;

transmitting the orbit parameters for available communication satellites from block 1 to block 7 enumeration of orbit parameters;

enumerate the parameters of the grouping by rotating the orbits of spacecraft around the center of mass of the Earth in three planes in block 7 enumeration parameters of the orbits;

transmitting the initial data of the transmitted message from block 2, the initial conditions of the simulation from block 3, the parameters of the partition sectors of the zone of possible location of the mobile surface object from block 6 and the current parameters of the orbits from block 7 to block 8 simulation;

using simulation modeling, the probability of delivering a message when the aircraft is moving to each sector of the zone of possible location of a surface object for all possible angles of rotation of the orbits of the constellation of communication spacecraft, taking into account the initial data of the transmitted message and the initial conditions of modeling in block 8;

transmitting the probability of bringing the message obtained during the simulation to block 9 for determining the integral coefficient of the possibility of bringing information;

determine the integral coefficient of the possibility of bringing information to the aircraft during its movement for the entire zone of possible location of a surface object as the arithmetic mean of the probabilities of bringing the message when moving to each sector from the partition zone in block 9;

choose the option of constructing an orbital constellation of the satellite communication system with the maximum integral coefficient of the possibility of bringing in block 10 the selection of the optimal constellation parameters;

transmit the parameters of the optimal grouping from block 10 to the mission control center 11;

a new grouping is formed through the mission control center 11, taking into account the optimal parameters, or the existing one is used by adjusting the orbits of spacecraft using thrusters.

The “industrial applicability” of the method is due to the ability to implement simulation elements on standard computers or using programmable logic integrated circuits, as well as the technical ability of modern and promising spacecraft to change the orbit on commands from the flight control center.

Comparison of the claimed method for constructing an optimal satellite communication system for guiding an aircraft to a moving surface object and the prototype shows that the claimed method differs significantly from the prototype.

General features of the proposed method and prototype

1. Use the existing constellation of communication and relay spacecraft.

2. Provide radio communication with moving objects.

3. Adapt the parameters of the communication system to the current conditions.

4. Provide maximum radio visibility.

Distinctive features of the proposed solution

1. Maximize the quality of communication for the entire route of the subscriber.

2. Optimize the grouping of communication and relay spacecraft.

3. Maximize the possibility of bringing information to an aircraft moving towards a moving surface target.

4. Simulation modeling is used to evaluate the effectiveness of all possible options for constructing a satellite communication system within the allowable values of variable parameters.

5. Adjust the parameters of the orbits of spacecraft for communication and data relay.

Thus, the claimed method for constructing an optimal satellite communication system for guiding an aircraft to a mobile surface object makes it possible to determine the parameters of the satellite communication system that will be optimal for a communication session with an aircraft moving towards a mobile surface target, the location and speed of which are not exactly known. At the same time, the integral coefficient of information delivery to the aircraft is maximized when it is pointed at a moving surface object, by determining, using simulation modeling, the optimal parameters of the orbits of the constellation of communication space vehicles, taking into account the signal-code design used and the parameters of the transmitted messages.

Literature

1. Patent RU No. 2265956, 2003

2. Patent RU No. 2522715, 2014

3. Patent RU No. 2755019, 2021

Claims (1)

A method for constructing an optimal satellite communications system for guiding an aircraft to a mobile surface object, which consists in setting the initial parameters of the spacecraft constellation in the form of Keplerian orbital parameters for available communication satellites; set the parameters of the transmitted messages, including the frequency of repetition of the message, the amount of the message, the data rate and the rate of error-correcting coding; set the initial conditions for modeling the constellation in the form of the location of spacecraft in space; specifying the launch site of the aircraft and the trajectory of its movement; set the possible location and speed of movement of the surface object; determine by means of simulation the probability of delivering a message during the movement of the aircraft to each sector of the zone of the possible presence of a surface object for all possible angles of rotation of the orbits of the constellation of communication spacecraft; grouping is formed taking into account the optimal parameters by adjusting the orbits of spacecraft, characterized in that the zone of possible location of a mobile surface object is divided into sectors with a size depending on the speed of the aircraft, the distance to the zone and the speed of the surface object; sorting out the grouping parameters by rotating the orbits of the spacecraft around the Earth's center of mass in three planes; determine the integral coefficient of the possibility of bringing information to the aircraft during its movement for the entire zone of possible location of the surface object as the arithmetic mean of the probabilities of bringing the message when moving to each sector from the partition zone; choose the option of constructing the orbital constellation of the satellite communication system with the maximum integral coefficient of the possibility of bringing.

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