KR20130073624A - Method and apparatus for avoiding collision between satellite - Google Patents

Abstract

PURPOSE: A collision prevention method and a device thereof are provided to maintain two satellites at a narrower distance than before by measuring the distance between them and performing collision prevention function based on the measurement results. CONSTITUTION: A radio signal transmission/reception unit (310) receives a first radio signal necessary in measuring the distance between a reference satellite and a satellite coming up close to the reference satellite. A measurement unit (330) measures the distance between the reference satellite and the incoming satellite based on the first radio signal and a second radio signal sent by a neighboring satellite. A judge unit (350) determines whether the measured distance comes within the range of a preset collision distance or not. A control unit (370) controls the orbit or posture of the reference satellite regarding to the judge unit's decision. [Reference numerals] (310) Radio signal transmission/reception unit; (330) Measurement unit; (350) Judge unit; (370) Control unit

Description

Method and device for collision avoidance between satellites {METHOD AND APPARATUS FOR AVOIDING COLLISION BETWEEN SATELLITE}

The present invention relates to a method and apparatus for collision avoidance between satellites, and more particularly, to a method and apparatus for collision avoidance between geostationary satellites.

Geostationary satellites, such as the speed of the earth's rotation, are widely used in telecommunications, broadcasting, earth observation, and navigational reinforcement because they appear to always be in a constant position on Earth. The geostationary orbit, which is approximately 36,000 kilometers from the Earth's equator and whose orbital inclination is nearly 0 degrees, is a finite resource, with a limited number of satellites that can operate on the geostationary orbit. The limited number of satellites that can be operated on a geostationary track is due to radio interference between satellites and the possibility of physical collisions between satellites.

In order to prevent radio interference and mutual disputes between satellites, procedures for registering and notifying satellite services using a constant communication frequency on a geostationary track with international organizations are in place.

A satellite operator can register a specific longitude and frequency on a geostationary track and place satellites on a specific longitude to perform satellite service. Thus, placing two or more geostationary satellites in a single longitude section In the case of satellite broadcasting service, one terrestrial antenna has the advantage of simultaneously receiving satellite signals transmitted from several satellites.

In terms of satellite operators, if multiple satellites are operated in the same orbit, the satellite service can be provided without interruption even if one or two of the satellites fail, which is advantageous compared to operating only one satellite.

When juxtaposing the satellites in the same geostationary position, one consideration is the physical collision between the satellites. When satellite collision occurs in the geostationary track, the satellites cannot be used, and debris generated by the collision can be generated on the geostationary track, which can damage satellites operating in other geostationary sections. In order to prevent such a collision, the orbital positions of the satellites operating in the same geostationary track section are managed and operated by the ground control station.

With the current technology, the number of satellites that share the same geostationary section is limited to eight because of the orbital error and the satellite's orbital error. The position of the geostationary satellite is calculated using the distance measurement data between the ground control station and the satellite, wherein one antenna of the ground control station may be used or two or more may be used to increase accuracy.

Since the GPS navigation system cannot be used in the geostationary position, the ground control station antenna is used to measure the geostationary satellite. The position of the geostationary satellite calculated using the ground control station antenna is estimated to be hundreds of meters to kilometers, and the satellite's accuracy is obtained by adding the operating error of the thruster for positioning the satellites east-west and north-south.

In the current control operation, the distance between satellites is measured by determining the trajectory of each satellite and predicting the distance between them. The current satellite control operation apparatus calculates the distance between two satellites in consideration of the orbit position accuracy including the orbit determination and orbit adjustment error in the above-described manner. As a result of the calculation, if the distance between the two satellites is within 5 km, it is determined that there is a possibility of collision.

The control of satellites generally requires a distance of more than 5 km between satellites. Due to these limitations, the number of satellites that can coexist in the same geostationary track is limited to eight.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In order to prevent collisions of satellites in the same geostationary section, the distance between the satellites is directly measured between the satellites and the collision avoidance maneuver is performed by using the measurement results directly. It is an object of the present invention to provide a method and apparatus for collision avoidance between satellites that can be kept closer.

In addition, another object of the present invention is to juxtapose many satellites in the same geostationary zone as compared to the prior art by preventing collision between satellites of a short distance.

In another aspect, the present invention is to efficiently use the finite orbital resources of the satellite, and to reduce the human and material burden on the operation of the ground control station.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention, which are not mentioned above, can be understood by the following description, and more clearly by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to an aspect of the present invention, there is provided a method of avoiding collision between satellites located in a geostationary track, the method comprising: transmitting a first radio signal for distance measurement to a proximity satellite approaching a reference satellite, the first satellite signal from the proximity satellite; Receiving a second wireless signal corresponding to a first wireless signal, measuring a distance between the reference satellite and the proximity satellite by using the first and second wireless signals, and the measured distance is within a preset collision range The method may include determining whether to recognize the position of the reference satellite according to the determination result.

According to the present invention as described above, in order to prevent collisions of satellites in the same geostationary section, the distance between satellites is directly measured between the satellites, and collision avoidance maneuvers are performed directly using the measurement results to keep the distance between the satellites closer. Can be.

In addition, according to the present invention, by avoiding collisions between satellites in close proximity, it is possible to juxtapose many satellites in the same geostationary section, and to effectively use the finite orbital resources of the satellites, as well as the ground pipe. It can reduce the human and material burden on the operation of the empire.

1 is a view showing an embodiment when eight satellites are juxtaposed in the geostationary section;
2 is a graph illustrating a relative distance between a reference satellite and the remaining satellites among eight satellites in the embodiment of FIG. 1;
3 is a block diagram illustrating a configuration of an apparatus for avoiding collision between satellites according to an embodiment of the present invention;
4 is a block diagram for explaining in more detail the collision avoidance device between satellites according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating an exemplary embodiment in which 20 satellites are juxtaposed on a geostationary interval using an inter-satellite collision avoidance device according to an embodiment of the present invention; FIG.
6 is a flowchart illustrating a collision avoidance method between satellites according to an embodiment of the present invention.

The above and other objects, features, and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, which are not intended to limit the scope of the present invention. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to denote the same or similar elements.

FIG. 1 is a diagram illustrating an embodiment in which eight satellites are juxtaposed in a geostationary track section. FIG. 2 is a graph illustrating a relative distance between a reference satellite and the remaining satellites of eight satellites in the embodiment of FIG. 1.

Referring to FIG. 1, eight satellites are operated within one geostationary interval by separating an eccentricity vector and an inclination angle vector, respectively. Referring to FIG. 2, which is a graph measuring a relative distance between any reference satellite and the remaining satellites of eight satellites for 24 hours, graph 202 is a distance between satellite 1 and satellite 2, and graph 203 is a reference satellite. distance between satellite 1 and satellite 3, graph 204 is the distance between satellite 1 and satellite 4, graph 205 is the distance between satellite 1 and satellite 5, and graph 206 is the reference satellite. Distance between 1) and satellite 6, graph 207 shows the distance between satellite 1 and satellite 7, and graph 208 shows the distance between satellite 1 and satellite 8.

Referring to FIG. 2, the satellite closest to the reference satellite (satellite 1) is satellite 2 (202), and it can be seen that the nearest satellite is 2 km. Referring to the measurement result of FIG. 2, in the same principle, each satellite may access up to 2 km of another satellite twice a day.

Therefore, in order to juxtapose more satellites, there is a need for a method that can avoid collisions in real time by approaching the satellites approaching, unlike conventional methods of calculating and predicting the distance between satellites at the ground control station to prevent collisions. Do.

Hereinafter, an apparatus and a method of collision avoidance between satellites in which a satellite performs collision avoidance on its own will be described with reference to FIGS. 3 to 6.

3 is a block diagram illustrating a configuration of an apparatus for avoiding collision between satellites according to an embodiment of the present invention. Referring to FIG. 3, an apparatus for avoiding collision between satellites 300 according to an embodiment of the present invention includes a wireless signal transceiver 310, a measurer 330, a determiner 350, and a controller 370. .

The wireless signal transceiver 310 transmits a first wireless signal for distance measurement to a proximity satellite approaching a reference satellite. The second wireless signal corresponding to the first wireless signal is received from the near satellite. In this case, the first and second wireless signals may be radio waves as a kind of beacon signal, and may be a tone signal or a pseudo-noise (PN) code according to a distance measuring method, but are not limited thereto.

The measurement unit 330 measures the distance between the reference satellite and the proximity satellite by using the first radio signal transmitted from the radio signal transceiver 310 and the second radio signal received from the proximity satellite. For example, according to the multi-tone ranging method, the measurement unit 330 may measure the distance by comparing the phase difference of the tone signal transmitted from the reference satellite with the phase difference of the tone signal returned from the proximity satellite. The measurement unit 330 may measure the distance by using the wireless signal transmitted and received by the above-described multi-tone ranging method or hybrid harmonic / pseudo-random method, but is not limited thereto.

The determination unit 350 determines whether the distance measured by the measuring unit 330 is within a preset collision range. In addition, the determination unit 350 may generate an alarm signal according to the determination result and transmit it to the control unit 370. The collision range may vary depending on the setting, but in the case of the present invention, since many satellites are to be juxtaposed in the geostationary trajectory section, the collision range may be set closer than the conventional alarm operating range.

The controller 370 controls the trajectory or attitude of the reference satellite according to the determination result of the determination unit 350. That is, when the determination result indicates that the distance between the reference satellite and the near satellite is within the collision range, the controller 270 may generate a control signal for changing the trajectory or the attitude of the reference satellite. The control signal generated in this way changes the trajectory or attitude of the reference satellite in a direction to avoid collision with the near satellite, so that the reference satellite can avoid collision with an approaching satellite without a command from the ground control station.

4 is a block diagram illustrating in more detail the apparatus for avoiding collision between satellites according to an embodiment of the present invention. Referring to FIG. 4, the inter-satellite collision avoidance apparatus 400 according to an exemplary embodiment of the present invention further includes a remote controller 320, a power supply unit 340, and a satellite propulsion unit 390 in addition to the components described with reference to FIG. 3. The remote control unit 320 may include a remote communication unit 325 and a data processor 327.

The remote control unit 320 is a module that communicates with a ground control station. The remote control unit 320 receives a remote command from a ground control station to control a satellite, and transmits various data measured by the satellite to the ground control station. However, the present invention, unlike the prior art that controls the collision avoidance of the reference satellite in the ground control station, the collision is avoided by using the components 310, 330, 350, 370 described in FIG. Note that the remote control unit 320 is for processing remote commands other than collision avoidance.

Looking at the remote control unit 320 in more detail, the remote communication unit 325 receives a remote command from the ground control station, and transmits the measurement data.

The data processor 327 converts the received remote command into command data and transmits the command data to each module, and measures the state of each module to generate measurement data. The measurement data generated by the data processing unit 327 is transmitted to the control station on the ground through the above-described remote communication unit 325 may be used for remote control of the satellite.

The power supply unit 340 generates power for supplying the satellite and distributes power to each module. Although the flow of power is not illustrated in the drawing, each module may use power supplied from the power supply unit 340.

The satellite propulsion unit 390 is a module for propelling satellites to change the trajectory and attitude of the satellites and moves the satellites according to the control signal generated by the controller 370.

FIG. 5 is a diagram illustrating an exemplary embodiment in which 20 satellites are juxtaposed in a geostationary track section using an inter-satellite collision avoidance apparatus according to an exemplary embodiment of the present invention. According to the present invention, as shown in FIG. 5, up to 20 satellites can be juxtaposed on the same geostationary trajectory section. Each juxtaposed satellite measures the distance between the satellites to monitor mutual access, and if the satellite approaches and falls within the collision range, it can perform orbit adjustment for collision avoidance itself.

6 is a flowchart illustrating a collision avoidance method between satellites according to an embodiment of the present invention.

Referring to FIG. 6, first, a first wireless signal for distance measurement is transmitted to a near satellite approaching a reference satellite (S610), and a second wireless signal corresponding to the first wireless signal is received from the near satellite (S630). ). Next, the distance between the reference satellite and the near satellite is measured using the first and second radio signals (S650). It is determined whether the measured distance is within a preset collision range (S670), and the trajectory or attitude of the reference satellite is controlled (S690) according to the determination result. Although not shown in the drawing, the step of controlling the orbit or attitude of the reference satellite according to the determination result may be performed in more detail as follows. For example, when the measured distance is within a predetermined collision range, a control signal for controlling the trajectory or attitude of the reference satellite may be generated, and collision may be avoided by moving the satellite according to the control signal.

According to the present invention, it is possible to perform satellite service while avoiding collision between the satellites by juxtaposing 8 or more satellites in one section of the geostationary orbit which is a limited resource. Thus, finite geostationary resources can be utilized to the maximum, thereby saving human and physical resources required to monitor and operate multiple satellites at ground control stations.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, But the present invention is not limited thereto.

Claims (1)

In the method of avoiding collision between satellites located in the geostationary orbit,
Transmitting a first wireless signal for distance measurement to a proximity satellite approaching a reference satellite;
Receiving a second radio signal corresponding to the first radio signal from the proximity satellite;
Measuring a distance between the reference satellite and the proximity satellite using the first and second radio signals;
Determining whether the measured distance is within a preset collision range;
Controlling the orbit or attitude of the reference satellite according to the determination result;
Inter-satellite collision avoidance method comprising a.

Images