RU2169989C2 - Method and system for establishing communications - Google Patents

Abstract

FIELD: establishing communications by means of space vehicles. SUBSTANCE: proposed method and system may be used for data exchange among various objects placed in orbits about planet, in its water or subsurface areas. Contact with objects in medium and long-wave (super long-wave) bands is established when cable system separated from space vehicle is lowered to altitude near lower boundary of ionosphere layer E and when signals coming from mentioned cable system are radiated/received. In the process contact between space vehicle and cable system can be maintained over high-frequency channels. Next lifting of cable system reconnects the latter to space vehicle. Sessions may be periodically repeated when, for example, several cable systems and space vehicle system are used and their orbital motion is coordinated with this cable system. EFFECT: enlarged frequency band for satellite communication system. 8 cl, 8 dwg, 2 tbl

Description

 The invention relates to the field of communication, carried out using space means, and can be used for information exchange between various objects located in orbits around the planet, on the surface of the planet, in its water area or under the surface.

 The preferred wavelength range for the present invention is medium, long and extra-long waves (~ 1 MHz to 1 KHz), used, in particular, for communication with underwater and underground objects, as well as for the study (radar) of natural and artificial formations in these areas the planet.

State of the art
Known global satellite communications systems, including a network of geostationary, 12-hour or low-orbit spacecraft (SC), transmitting data of various types between certain regions of the Earth. Such data are transmitted mainly through television and radio channels in the meter ... centimeter wavelength ranges (~ 10 MHz ... 10 GHz), for which the lower ionosphere of the Earth (layers F, E, D) is transparent - see , for example, [1]: A.M. Bonch-Bruevich, V.L. Bykov et al. Satellite communications systems. M., "Radio and Communications". 1992.S. 11-31.

 These systems, which are widely used for consumer, commercial, and navigation communications, are nevertheless limited by the region of sufficiently low frequencies (medium... Long waves), for which the lower ionosphere is opaque, so the use of traditional satellite systems is difficult (for example, it depends on the time of day ) or not possible at all.

 However, some special tasks characterizing the field of predominant use of the invention require work precisely in these wavelengths.

 Known communication methods and systems based on the use of space cable systems (TS), the dimensions of which (~ 10 ... 100 km) allow the generation of DV and SDV signals during the interaction of electrically conductive elements of the TS with near-Earth plasma - see, for example, [ 2]: A.V. Andreev, N.N. Khlebnikov. Flexible communications space systems. Results of science and technology. Rocket science and space technology. T. 12.M., 1991. S. 134-136; 153.

 Such signals are transmitted mainly through ionospheric waveguides, the natural position of which relative to the Earth ("hot spots" on the surface, mainly in the polar regions) cannot be selected at will, and, in addition, a small part of the signal energy enters the waveguide.

 Other methods and systems of information communication between the spacecraft and the planet are also known, for example, based on the separation of a part of the orbital spacecraft (capsule with accumulated information), its transfer to the trajectory of approach to the planet and subsequent descent in the atmosphere, where this part is then selected and contained in her information is used by the consumer. Energy-efficient separation and transfer to the path of approach to the planet of the indicated part of the spacecraft can be carried out using vehicles of sufficient length - see the indicated source [2], p. 54.

 The disadvantage of methods and systems of this type are, obviously, extremely stringent restrictions on the spatio-temporal characteristics of information exchange, the practical impossibility of operational two-way communication of spacecraft with ground (especially deep-sea and underground) objects, etc.

 Nevertheless, in certain techniques and means of such communication, which in their selected aggregate can be taken as the closest analogues of the proposed method and system, there is a positive moment, such as the possibility of multiple and energy-efficient convergence of the transceiving parts of the spacecraft with the planet - so much so that it becomes possible (due to the distinguishing features of the present invention) medium and long-wave radio communication with objects of interest.

 In this regard, the objective and purpose of the invention is to develop such a method and such a communication system that implements it, with which it is possible to continuously (periodically) and without significant energy costs transmit and / or exchange data mainly on medium, long and extra-long waves between orbital spacecraft and various , preferably special (immersed and buried) objects.

SUMMARY OF THE INVENTION
The solution to the problem and the purpose of the present invention are achieved in that the proposed method for communicating includes the following operations:
launching into orbit around the planet, mainly circular, at least one spacecraft equipped with means for information exchange in a given wave range, and associated with the spacecraft;
placing part of these funds on the vehicle connected to the spacecraft;
placement of the vehicle in the region lying below the orbit of the center of mass of the spacecraft, on which this spacecraft moves as a result of the indicated withdrawal;
separation of the vehicle from the spacecraft, as a result of which it passes to the descending section of the trajectory of approach to the planet;
radiation and / or reception of vehicle signals when it moves along a trajectory in the area of the pericenter (with minimum heights above the planet's surface);
the connection of the vehicle with the spacecraft after its movement along the ascending section of the approach path to the planet.

 In this case, in the process of moving the vehicle along the path of approach to the planet between it and the spacecraft, remote communication can be maintained (via radio, laser and other channels), mainly when the vehicle emits / receives signals in the area of the pericenter, thus forming a communication line between itself Spacecraft and objects on Earth through the vehicle.

 The trajectory of the approach of the vehicle to the planet should be chosen so that in the pericenter region the receiving-radiating ("lower") part of the vehicle is below the ionospheric layer F (~ 180 km) or even below the layer E (~ 100 km). The latter condition is critical for reasons of dynamic heating of the cable of the vehicle by atmospheric flow, and also because of the possible development of instability of the relative movement of the cable [2], p. 82-90. However, the relatively short time of the communication session at such heights and some special measures can minimize these negative phenomena.

 Several spacecraft can be placed in a circular orbit (orbits) distributed along the orbit (in orbits) so that each vehicle — after separation from one spacecraft, conducting a communication session in the pericenter region and moving along the ascending section of the approach path to the planet — can approach and connect to another spacecraft (vehicle transfer scheme from one spacecraft to another).

 In the general case, the orbits of the spacecraft and the trajectory of the vehicle can be corrected by various means (including in the "orbital engine / generator" mode [2], pp. 72-74) to ensure the cyclic operation of the communication system according to the invention.

A communication system implementing the proposed method comprises:
at least one spacecraft, placed mainly in a circular orbit around the planet and equipped with means of information exchange in a given wavelength range;
TS equipped with means of docking and separation from the spacecraft, on which a part of the indicated means for information exchange is located;
auxiliary controls for the movement (navigation, correction systems, etc.) and the operation of the supporting on-board systems (orientation, stabilization, antenna pointing, etc.) of the spacecraft and the vehicle in their joint and separate flight.

 The indicated means of information exchange may include means for maintaining remote communication between the spacecraft and the vehicle during their separate flight.

 A communication system may comprise several spacecraft located along one or more orbits.

 The analysis of the prior art did not reveal technical solutions with an identical set of features, which is why the invention is novel. Separately, well-known techniques and elements are combined in the present invention so as to achieve an unobvious final result, which indicates that the invention meets the condition of an inventive step. The industrial applicability of the invention is justified by the following examples of its implementation.

 The invention is illustrated by the following graphic materials.

 In FIG. 1 shows a simplified structure of the lower ionosphere of the Earth.

 In FIG. 2 schematically shows the effect of layer E on the radiation pattern of the radiating element of the vehicle located below this layer.

 In FIG. Figure 3 shows a simplified diagram of the use of a "waveguide" between layers E and D.

 In FIG. 4 gives an example of the simplest orbital construction of a system according to the invention.

 In FIG. 5 presents a schematic structural diagram of a system for implementing the proposed communication method.

 In FIG. 6 shows the system of FIG. 5 after separation of the spacecraft and the vehicle.

 In FIG. Figure 7 shows the possible working configuration of the vehicle during its movement at minimum heights above the Earth.

 In FIG. 8 shows a possible modification of the structural circuit of FIG. 5.

где N - электронная концентрация (см^-3). В таблице 1 приведены ориентировочные характеристики ионосферы Земли с точки зрения пропускания радиоволн разного типа (см., например, [3]: Н.М. Изюмов и Д.П. Линде. Основы радиотехники. М.-Л. "Энергия". 1965. С. 171-189).Preferred Embodiments
As is known, in the lower ionosphere of the Earth it is possible to conditionally distinguish a number of layers (Fig. 1) with different, depending on the time of day, solar activity and other factors, electron concentration, directly affecting the propagation of radio waves. Strong refraction and reflection of radio waves (with vertical incidence) occurs near the critical frequency

where N is the electron concentration (cm ^-3 ). Table 1 shows the approximate characteristics of the Earth’s ionosphere in terms of transmission of various types of radio waves (see, for example, [3]: NM Izyumov and DP Linde. Fundamentals of radio engineering. M.-L. "Energy". 1965 S. 171-189).

 Medium, DW and SDW waves practically do not pass through layers E and F. The DV and SDW signals do not overcome the lowest (60 ... 90 km) layer D. It is important to note, however, that this layer almost completely disappears in night time (see Fig. 1, table. 1).

 According to the invention, communication sessions in the ranges of interest are carried out using receiving-emitting elements located below or at the lowest boundary of the layer E, i.e. at altitudes of about 110 ± 10 km (moreover, lengths of ~ 10 km can actually be attributed to active antenna elements). The reflective properties of layer E are used to increase the directivity of the antenna (see [3], pp. 150-153), as shown schematically in FIG. 2.

 Due to tangible aerodynamic drag, the receiving-radiating (antenna) element, with its corresponding performance and control, can occupy various intermediate - between vertical and horizontal - positions. This provides additional opportunities to adjust the characteristics of the reception-emission of radio waves.

 For radio communication on long and extra-long waves, a “waveguide” between layers E and D with an output / input on the night side of the Earth (where layer D disappears) can also be used - see FIG. 3.

 The object with which the vehicle communicates is located in the region ("spot") S on the night side of the Earth, where the signals from the "waveguide" get. From the object to the vehicle, the signals can be sent in the opposite way. In principle, “windows” in layer D can be temporarily made (on the day side) artificially (using plasma damping compounds), but this is undesirable for environmental reasons. In order to be able to lower part of the vehicle below layer D (i.e., up to 80-60 km), it is necessary to solve the complex problems of thermal heating and compensate for the very significant aerodynamic drag of the vehicle.

An example of constructing an elementary orbital system according to the invention is given in FIG. 4. In each communication session, the vehicle detaches from KA ₁ and moves onto the approach path O ' ₂ to the planet. In the lower section, information is exchanged between the vehicle (and, through it, between spacecraft ₁ ) and ground objects, as shown in FIG. 2-3. After that, the vehicle passes to the ascending section of the trajectory, which approaches the initial orbit, ahead of KA ₁ by a certain distance.

It should be noted that when the spacecraft and the vehicle are uncoupled, the orbit of the spacecraft will also change - in this case, the spacecraft ₁ will go to a higher orbit, touching the initial orbit O ₁ at the point of uncoupling (here, for simplicity, it is assumed that the mass KA _{1 is} much larger than the mass of the vehicle, so that the new orbit of the spacecraft practically coincides with O ₁ ).

To "pick up" the vehicle at the point of convergence with the orbit O ₁ in the system, a second spacecraft ₂ can be provided
In a preferred embodiment, the system according to the invention contains KA 1 (Fig. 5-6) and a cable system with a main cable-cable 2 (power part and an electric or fiber optic communication line) and a radiating and / or receiving (antenna) section 3. Docking devices - the separation of the spacecraft 1 and the vehicle can be combined with means 4 for remote communication between the spacecraft and the vehicle (for example, through a high-frequency or laser channel).

In the initial state, the center of mass of the bundle moves in the O ₁ orbit, and the center of mass of the vehicle - in the O ₂ orbit (Fig. 5). In this example, these orbits are circular.

 An end unit 5 may be provided in the system with the equipment necessary for the operation of the transceiver section 3 and the functional interface of this section with the rest of the information part — in the cable cable 2 and means 4.

 In addition to these functions, block 5 acts as a “counterweight” and, possibly, protects section 3 (at least partially) from heating in the atmosphere, as well as to control the position and movement of the entire cable (both in the atmosphere and outside it) .

 A useful modification of the system of FIG. 5 may serve as shown in FIG. 8. According to this scheme, the docking and separation device, combined with means 4 for remote communication, contains an additional power cable (cable-cable) with parts 6 and 7, respectively, on the vehicle and the spacecraft. These parts of the cable are equipped with the necessary release-pulling mechanisms (winches), end locks and means of mutual trapping at the location of the locks (that is, at least one of the cables 6 or 7 can be made active, see, for example, [2] p. 120-123).

The presence of an additional cable 6-7 facilitates the "pickup" of the vehicle when approaching spacecraft ₂ (Fig. 4), especially since the removal of the vehicle from the original O ₁ orbit increases due to some atmospheric braking in the perigee region.

It is clear that several elementary orbital systems similar to that shown in FIG. 4, by, for example, even distribution along several spacecraft orbit: KA _1, KA _2, ..., and there are several TS, respectively synchronized with the AC and interacting with them at the high points of the trajectories of type G _'2. This may be selected by methods known in the art, the required point communication sessions (in perigee trajectories G 'TC _2), linking them to the position of objects in the world, the frequency and duration of communications, etc.

 For a more specific idea of the characteristics of the proposed communication system, some simple estimates are given below.

The maximum removal of the vehicle vertically (decrease along the radius of the orbit) when uncoupling from the spacecraft — without preliminary buildup of the vehicle — is about 7δ, where δ is the distance between the initial orbits O ₁ and O ₂ in FIG. 5.

With a strong buildup we get about 14δ, and with a moderate ≈ 10δ [2; from. 52-53]. From here one can estimate the required length of the cable 2 of the vehicle (Fig. 5) - for a given altitude of the main orbit (O ₁ ) of the spacecraft and the minimum flight height of the site 3-5 TC (see Fig. 5-7). Take the last 100 km.

Lagging KA ₁ separated away from the vehicle through one orbit O ₁ (excluding changes orbit G _'2 by a small vehicle deceleration) will be approximately 12πδ ≈ 38δ. This distance determines the arrangement of several spacecraft: spacecraft ₁ , spacecraft ₂ , ... along the orbit O ₁ .

 In the table. 2 corresponding estimates are given.

It can be seen from the data presented that at the characteristic altitudes of a long spacecraft flight (~ 500 ... 450 km), the length of the vehicle is moderate and the mass of the power cable (for materials such as Kevlar and CBM) is small. The spacecraft lag (i.e. the distance between KA ₁ and KA ₂ in Fig. 4) is, for the same altitudes, approximately 2000 km / revolution.

T. about. , to build a system of "continuous" communication (in which each vehicle would interact with one of the spacecraft at the end of each revolution along the O ' ₂ trajectory), at least 20 spacecraft in orbit O ₁ would be required. Moreover, the number of vehicles could be from 1 to 20. The period between consecutive communication sessions of each vehicle in such a system would be about 1.5 hours,

Claims (8)

 1. A communication method, including putting into orbit around the planet, mainly circular, at least one spacecraft (SC), equipped with means for information exchange, and connected to the SC cable system (TS), which also contains means for information exchange , placing the vehicle in the region lying below the orbit along which the center of mass of the spacecraft moves as a result of the indicated withdrawal, characterized in that the said means are capable of information exchange in a given wavelength range not, at the same time, the vehicle is separated from the spacecraft, as a result of which it goes to the descending section of the approach path to the planet, the vehicle signals are emitted and / or received during its movement on the track section in the area of its pericenter, and then the vehicle is reconnected with the spacecraft after its movement along the ascending section of the trajectory of approach to the planet.  2. The method according to claim 1, characterized in that in the process of moving the vehicle along the path of approach to the planet between the vehicle and the spacecraft, remote communication is maintained.  3. The method according to claim 2, characterized in that the specified remote communication is supported mainly by emission / reception of TS signals in the region of the specified pericenter.  4. The method according to claim 1, characterized in that the trajectory of the approach of the vehicle to the planet is chosen so that at least a portion of the radiating and / or receiving-radiating means of the vehicle in the region of the indicated pericenter is located below the earth’s ionospheric layer E.  5. A communication system comprising at least one spacecraft, placed mainly in a circular orbit around the planet and equipped with means for information exchange, a vehicle on which means for information exchange are also located, as well as auxiliary means for controlling the movement of the spacecraft and vehicle, the fact that these means for information exchange are made with the possibility of this exchange in a given wavelength range, the vehicle is equipped with means for docking and separation from the spacecraft, and these means Aviation made with the ability to control the motion of the spacecraft and the vehicle in both their joint and separate flight.  6. The system according to claim 5, characterized in that the said means for information exchange include means for maintaining remote communication between the spacecraft and the vehicle during their separate flight.  7. The system according to claim 5, characterized in that it contains several spacecraft located along one or more orbits.  8. The system according to claim 7, characterized in that it contains several vehicles interacting alternately with these spacecraft.

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