RU2800530C1 - Method for controlling the flight of a low-orbit spacecraft through navigation spacecraft of the glonass system using a backup transmission channel with code division of command-program information - Google Patents

Abstract

FIELD: code division radio communication systems.

SUBSTANCE: to control the flight of a low-orbit spacecraft, navigation satellites of the GLONASS system are used as relay satellites. Command-program information is recorded with code division when organizing a backup control channel in the backup bits of navigation frames. Navigation frames are received on a low-orbit spacecraft using the consumer's onboard navigation equipment.

EFFECT: increased stability and efficiency of control of a low-orbit spacecraft, simplification of algorithms for establishing and maintaining communication between a navigation satellite-relay and a spacecraft.

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Description

The field of technology to which the invention belongs

The invention relates to the field of radio communication systems with code division channels or using spread spectrum signals and can be used for the transmission of command and program information (CPI) in the control loop of a low-orbit spacecraft (LEV), as well as in the construction of communication systems and information transmission for organization of management of promising satellites equipped with consumer onboard navigation equipment (OBNAP) in the mode of their regular operation or under special conditions in the information interaction loop with the onboard control complex as a backup channel for transmitting the CPI.

State of the art

At present, to control the satellite, approaches are mainly used similar to the method of controlling the flight of a spacecraft (SC) through the flight control center (MCC), which is capable of receiving telemetry information and operational control information from the spacecraft (control object) through radio telemetry and transmitting it to the spacecraft command and program information, only in those parts of the orbital flight in which the flight path of the spacecraft (control object) passes in the radio visibility zone of command and measuring stations from the means of the ground control complex of the spacecraft or through special spacecraft repeaters (Grigoriev K.L. Theoretical foundations of automated control of space facilities, Part 1. Fundamentals of technology of automated control of space facilities: textbook / K.L. Grigoriev, S.A. Osipenko. - St. Petersburg: VKA named after A.F. Mozhaisky, 2015. - 60 p. ).

The disadvantage of this method is the need to distribute a wide network of ground control systems over the surface of the globe to ensure continuous communication between the MCC and the spacecraft and the system of satellite relays, which in modern conditions is a very costly approach, especially considering the trend towards the creation of multifunctional satellite systems.

If we talk about the special operating conditions, which are understood as the difficulties caused by the degradation of the spacecraft constellation as a result of malfunctions or the impact on the space infrastructure as a result of military operations, then the use of the resource of space navigation systems for organizing backup control channels for spacecraft is a very urgent technical problem.

From the prior art there is a method of space communication (RU2549832C2, published on 07/27/2015), according to which the slave satellites are equipped with radio navigation equipment, a navigation and traffic control system; inter-satellite communication is supplemented with official two-way communication channels; leading satellites are located in the visibility zones of targeted ground communication points that are inaccessible to slave satellites; control of slave satellites and control over their technical condition is carried out by means of a master satellite, which is constantly in the visibility zones of at least one ground command and measuring point and ground communication point - antipodes to targeted ground communication points.

The disadvantage of this method is the large delays in the transmission of information and the need to allocate part of the bandwidth from the total inter-satellite resource or early equipping the spacecraft with specialized transceiver equipment for organizing two-way service communication.

A multi-level satellite communication system is also known from the prior art (RU2575632C2, published on February 20, 2016), which is a constellation of three repeater satellites uniformly spaced relative to each other in the geostationary orbit (GSO) and an orbital constellation of observation and communication spacecraft, consisting of a low-altitude constellation of surveillance spacecraft and medium-altitude constellation of communication spacecraft, the ground segment consists of ground-based complexes for receiving and transmitting target information and controlling a low-altitude constellation of surveillance spacecraft and a medium-altitude constellation of communication spacecraft, as well as ground-based complexes for receiving and transmitting target information and controlling the orbital constellation of repeater satellites on GSO.

The disadvantages of this method-analogue are:

1) Large delays in satellite communication channels, which reduce the efficiency of receiving telemetry information from the control object and bringing control information to the control object, due to the fact that the orbital altitude of the relay satellites in the GSO is about 36,000 km.

2) Low survivability of the communication system, due to the fact that if one relay satellite on the GSO fails, communication with the group of spacecraft located in its radio visibility zone will be lost.

3) The need for constant pointing of highly directional antenna systems of geostationary relay satellites to the spacecraft that is the object of control, arising due to the large length of the inter-satellite radio link.

The closest in technical essence to the claimed method and selected as a prototype is the invention "SC flight control system using low-orbit satellites as repeaters interconnected by inter-satellite communication lines (RU2713293C1, published on 02/05/2020)".

The prototype invention is a spacecraft flight control system using low-orbit satellites as repeaters, interconnected by inter-satellite communication lines, which is a satellite digital transport network for transmitting control information from the mission control center to the spacecraft control object in forward and reverse communication channels, via low-orbit spacecraft relays, each of which is connected by inter-satellite radio links with neighboring spacecraft and with the air-to-Earth radio link, characterized in that each low-orbit satellite-relay is equipped with two low-directional transmit-receive antennas located along the minus Y and +Y axes, representing they are open ends of waveguides, or helical antennas, or a system of helical antennas that provide information exchange with the spacecraft control object, while each spacecraft control object is equipped with two or four low-directional transmit-receive antennas located along the minus Y and +Y axes and representing the open ends of waveguides, or helical antennas, or a system of helical antennas.

The disadvantages of the known technical solution-prototype include the need to launch additional low-orbit spacecraft repeaters, as well as meeting the requirements for a high-precision synchronization system.

Disclosure of invention

The technical result of the invention consists in increasing the stability and efficiency of control of a low-orbit spacecraft, simplifying the algorithms for establishing and providing communication in an inter-satellite radio link between a navigation satellite relay and a low-orbit spacecraft (control object) due to the absence of the need to point highly directional antennas through the use of a backup command transmission channel -program information through GLONASS navigation spacecraft with code division and global coverage of the navigation field. The consumer's on-board navigation equipment is used as a receiving device for receiving command and program information as part of the reserve bits of navigation frames.

To do this, it is proposed to expand the control system of a low-orbit spacecraft (control object), containing: a low-orbit spacecraft, a ground-based control complex for a low-orbit spacecraft, a control center for the space complex of the GLONASS system (functionally), as well as a GLONASS satellite navigation system (functionally), containing navigation satellites as relay satellites. At the same time, the GLONASS navigation spacecraft emit a radio navigation signal with a code division and contain an onboard command and measurement system connected to the inter-satellite communication equipment that communicates between the navigation satellites. The low-orbit spacecraft contains consumer navigation equipment connected to the onboard control complex and operating on the navigation field of the GLONASS system.

The task that the proposed method solves is to control the flight of a low-orbit spacecraft through the navigation spacecraft of the GLONASS system using a backup transmission channel with code division of command-program information, by using reserve digits of navigation frames to generate control commands for low-orbit spacecraft.

The inventive reserve flight control channel of a low-orbit spacecraft with code division is formed using GLONASS navigation satellites as repeaters, each of which is connected by inter-satellite radio links with neighboring navigation satellites and an air-to-Earth radio link with a station for laying and receiving command and program information GLONASS systems, and the low-orbit spacecraft is equipped with on-board navigation equipment of the consumer, which is connected by an information channel with the onboard control complex of the low-orbit spacecraft and is capable of extracting command and program information from the backup bits of navigation frames. At the same time, as part of the command-program information, there is a marker indicating that the transmitted information belongs to a specific controlled SV, with the help of which the code separation mechanism of control channels is implemented.

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

Fig. 1 - Scheme of organizing control of a low-orbit spacecraft using two navigation satellites of the GLONASS system as relay satellites.

In FIG. 1 positions mean the following:

1 - flight control center for a low-orbiting spacecraft;

2 - command and measuring station from the ground control complex of the low-orbit spacecraft;

3 – main feeder radio link for transmission of command and program information (main control channel);

4 - low orbit spacecraft - control object;

5 – GLONASS space complex control center;

6 - station for bookmarking and receiving command and program information of the GLONASS system;

7 - reserve feeder radio link for transmission of command and program information (backup control channel);

8 - navigation satellite of the GLONASS system;

9 - inter-satellite radio link of the GLONASS system;

10 - navigation satellite of the GLONASS system;

11 - radio navigation signal of the GLONASS system;

12 - on-board navigation equipment of the consumer.

To solve the problem of controlling the flight of a low-orbit spacecraft through navigation spacecraft of the GLONASS system using a backup transmission channel with code division of command-program information, a method is proposed, which consists in the following:

control in the normal operation mode through the flight control center 1, by transmitting command and software information through the command and measuring station 2 from the ground control complex via the main feeder radio link 3, low-orbit spacecraft 4;

introducing into the command-program information a marker of belonging to the required low-orbit spacecraft 4, thereby implementing the mechanism of code division of control channels;

transmit command and program information with code division of control channels, in an emergency or when the NSC 4 is outside the radio visibility zone of the command and measuring station 2, to the control center of the space complex of the GLONASS system 5;

transmit command and program information with code division of control channels from the control center of the space complex of the GLONASS system 5 to the station bookmark and receive command and program information 6;

using a mathematical model of a constellation of navigation satellites of the GLONASS system, a navigation satellite-relay from the constellation is determined, having the best radio visibility conditions with a low-orbit spacecraft 4 according to the criterion of the maximum signal-to-noise ratio;

command and program information is transmitted with code division of control channels from the station for laying and receiving command and program information 6 through the backup feeder line for transmitting command and program information 7 to the navigation satellite relay of the GLONASS system 8;

transmit command-and-program information with code division through the inter-satellite radio link 9 to the navigation satellite-relay of the GLONASS system with the best radio visibility conditions 10 with a low-orbiting spacecraft 4;

write command-program information with code division in the reserve bits of the navigation frames;

transmit navigation frames containing command-program information with code division, radio navigation signals 11;

receive navigation frames containing command-program information with code division, on the low-orbit spacecraft 4, using the onboard navigation equipment of the user of the GLONASS system 12;

determine the belonging of the navigation frame that has received it to the low-orbit spacecraft 4;

extract from the navigation frame in the low-orbit spacecraft 4 command-program information in case of belonging to this spacecraft;

perform in the low-orbit spacecraft 4 received command and software information.

The "industrial applicability" of the method is due to the possibility of implementing it using the standard functionality of the GLONASS system.

Comparison of the claimed method for controlling the flight of a low-orbit spacecraft through the navigation spacecraft of the GLONASS system using a backup transmission channel with code separation of command-program information and a prototype shows that the claimed method differs significantly from the prototype.

General features of the proposed method and prototype:

1. Command and program information is transmitted through two repeater satellites.

2. The low-orbit spacecraft is controlled using command and program information.

3. Command and program information is transmitted from the flight control center.

4. Use backup control channels for low-orbit spacecraft.

5. Choose the best relay satellite according to the criterion of the maximum signal-to-noise ratio.

Distinctive features of the proposed solution.

1. GLONASS navigation satellites are used as repeater satellites.

2. Command and program information is recorded with code division when organizing a backup control channel in the backup bits of the navigation frames of the GLONASS system.

3. Command and program information is received via a backup control channel using only one antenna, which is part of the onboard navigation equipment of the user of the GLONASS system.

Thus, the claimed method for controlling the flight of a low-orbit spacecraft through the navigation spacecraft of the GLONASS system using a backup transmission channel with code division of command-program information is a satellite digital transport network for transmitting command-program information designed to relay control information from the flight control center to the low-orbit spacecraft (control object) in case of unavailability of the direct communication channel.

The use of a backup channel for transmitting command and software information with code division to low-orbit spacecraft, implemented using backup bits of navigation frames of the GLONASS satellite navigation system, will allow you to have access to all low-orbit spacecraft simultaneously, which will ensure high reliability, stability and efficiency of the control system.

Claims (1)

A method for controlling the flight of a low-orbit spacecraft through navigation spacecraft of the GLONASS system using a backup transmission channel with code division of command-program information, which consists in the following: control in the normal operation mode through the flight control center of a low-orbit spacecraft; introducing into the command-program information a marker of belonging to the required low-orbit spacecraft; transmit command and program information with code division of control channels, in an emergency situation or when the low-orbit spacecraft is outside the radio visibility zone of the command and measuring station, to the control center of the space complex of the GLONASS system; transmit command and program information with code division of control channels from the control center of the space complex of the GLONASS system to the station of bookmarking and receiving command and program information; determine, using a mathematical model of the GLONASS navigation satellite constellation, a navigation satellite-relay from the constellation, having the best radio visibility conditions with a low-orbit spacecraft according to the criterion of the maximum signal-to-noise ratio; command and program information is transmitted with code division of control channels from the station for laying and receiving command and program information through a backup feeder line for transmitting command and program information to a navigation satellite-relay of the GLONASS system; transmit command-and-program information with code division via an inter-satellite radio link to a navigation satellite-relay of the GLONASS system with the best radio visibility conditions with a low-orbit spacecraft; write command-program information with code division in the reserve bits of the navigation frames; transmit navigation frames containing command-program information code division; receive navigation frames on a low-orbiting spacecraft; determining the ownership of the navigation frame; extract from the navigation frame in the low-orbit spacecraft command-program information in case of belonging to this spacecraft; carry out in a low-orbit spacecraft the received command and program information, characterized in that: they use navigation satellites of the GLONASS system as relay satellites; write command-program information with code division when organizing a backup control channel in the backup bits of the navigation frames of the GLONASS system; receiving navigation frames containing command-program information with code division on a low-orbit spacecraft using on-board navigation equipment of the user of the GLONASS system.