RU2596194C1 - Spacecraft for calibrating radar stations - Google Patents

Abstract

FIELD: astronautics.

SUBSTANCE: invention relates to space engineering, particularly, to design of spacecrafts (SC) for calibrating radar stations. SC comprises a body with instrument compartment, engine unit, orientation and stabilization systems, solar batteries. SC body is made in the form of a rectangular prism, one of the faces of which has a radio-reflecting surface, and is equipped with a flat rectangular plate of radio-reflecting material pivotally connected to the face of the rectangular prism, having radio-reflecting surface. Flat rectangular plate is equipped with a opening mechanism and the fixing unit to one of the faces of the SC body rectangular prism. SC additionally has command radio link equipment (CRLE), consumer navigation equipment (CNE) of GLONASS and/or GPS space systems, onboard computer system (OCS), microcontroller (MC), unit for interfacing the orientation and stabilization systems and fixing assembly with the microcontroller. CRLE, CNE, OCS, MC, unit for interfacing the orientation and stabilization systems and fixing assembly with the microcontroller are interconnected.

EFFECT: high efficiency of calibrating a radar station, expanded performances of the SC during calibration of ground and sea-based radar stations operating on circularly polarized waves with parallel reception of reflected signals, as well as possibility of calibration by value of the SCS of the potential radar stations at small elevation angles (3-5) of degrees and in the operation mode with low radiation power.

11 cl, 6 dwg

Description

The invention relates to space technology, in particular to the design of spacecraft for radar calibration.

There are various options for spacecraft designed to calibrate radar stations, for example spherical spacecraft with a reference reflective surface [1] p. 47-49. In the United States, starting in 1964, standard spherical artificial Earth satellites were launched to calibrate the radar [2] p. 37. In the USSR, Typhoon-2 spacecraft were created and used at various time periods. The spacecraft includes 24 shooting devices with spherical reference reflectors [3] p. 198-200.

Spheres are convenient reference scatterers whose EPR can be calculated accurately [4] p. 204. The reference sphere has the advantage of calibrating the radar because, due to its symmetry, the EPR value is constant [4] p. 205.

A disadvantage of a spherical spacecraft with a reference reflective surface is the impossibility of using it for EPR calibration of radars operating on circular polarized waves during parallel reception of reflected signals, since a spherical reflector is invisible for such radars [5] p. 103.

Known spacecraft with reference reflectors for alignment and calibration of complexes of ground and space-based - patent RU 2481248 "Spacecraft with reference reflectors". This spacecraft with reference reflectors is taken as a prototype.

The prototype also uses spherical reference reflectors to calibrate the radar.

The disadvantage of the prototype is the inability to use the proposed spherical reflectors for calibration by the magnitude of the EPR of radars operating on circular polarized waves with parallel reception of reflected signals. Another disadvantage of the prototype for radars operating on waves of horizontal, vertical, as well as circular polarization with orthogonal reception of reflected signals is the small EPR of the spherical reference reflectors used. So, for example, with a sphere diameter of 25 cm and a radar wavelength of 7 cm, its EPR will be only 0.04 m ² , and with a radar wavelength of 1.9 m, the EPR of such a spherical reflector is 0.013 m ² [1] p. 49, table 2.1.3. Significantly increase the EPR of a spherical reflector, i.e. its radius is impossible due to the overall limitations of the launcher placed on board the spacecraft.

The technical result of the proposed invention is to increase the efficiency of radar calibration, expand the functionality of the spacecraft when calibrating ground-based and sea-based radars operating on circular polarization waves with parallel reception of reflected signals, as well as the ability to calibrate the ESR value of high-potential radars at small elevation angles (3 -5) degrees and in the operating mode with reduced radiation power.

The specified technical result is achieved in that the spacecraft body is made in the form of a direct prism 1, one of the faces 2 of which has a radio-reflective surface. In addition, the spacecraft body is supplemented by a flat rectangular plate 3 of radio-reflective material pivotally connected to a face of a direct prism having a radio-reflective surface (see Fig. 1). Moreover, a flat rectangular plate 3 of radio-reflective material is deployed relative to the face 2 of a direct prism having a radio-reflective surface so that a dihedral angular reflector is formed with faces turned through an angle α in the range from (90-Δ) degrees to (90 + Δ) degrees, where Δ - is determined from the ratio:

0 <Δ <18λ / a,

λ is the wavelength of the calibrated radar;

a is the face size of the corner reflector (see Fig. 1, Fig. 2).

In this case, a flat rectangular plate of radio-reflecting material is equipped with a disclosure mechanism 4 and a fixing unit 5 (see Fig. 2, Fig. 3). The spacecraft has additionally introduced command radio link equipment (AKRL), consumer navigation equipment (NAP) of the GLONASS and / or GPS space systems, on-board computer system (BVS), a microcontroller, an interface unit for the orientation and stabilization system, and a fixation unit with a microcontroller.

Moreover, the ACRL input and output are informationally connected to the BVS, the NAP output is connected to the first input of the on-board computer system, the first output of the on-board computer system is connected to the first input of the microcontroller, the first output of the microcontroller is connected to the first input of the interface unit, the first output of the interface unit is connected to the input of the orientation system and stabilization. The output of the orientation and stabilization system is connected to the second input of the interface unit, the second output of the interface unit is connected to the second input of the microcontroller, the second output of the microcontroller is connected to the second input of the onboard computer system, which controls the process of orientation of the spacecraft relative to the calibrated radar. In addition, the third output of the on-board computer system is connected to the third input of the microcontroller, the third output of the microcontroller is connected to the third input of the interface unit, and the third output of the interface unit is connected to the input of the fixation unit of a flat rectangular plate of radio-reflecting material to the direct prism of the spacecraft body.

In addition, a flat rectangular plate of radio-reflective material is made with the possibility of its folding, while in the transport position it is laid and fixed so that it is adjacent to one of the faces of a direct prism, and in the open position it is turned at an angle α relative to the face of a direct prism having a radio-reflective surface (see Fig. 2, Fig. 3).

In addition, the fixation unit of a flat rectangular plate of radio-reflecting material to the spacecraft body is made with an electromechanical system for checking and stripping.

In addition, the mechanism for opening a flat radio-reflecting plate is made, for example, in the form of a spring drive.

In addition, the face of a direct prism having a radio-reflective surface and a flat rectangular plate of radio-reflective material have the same dimensions.

In addition, the flat rectangular plate has a radio-reflective surface on the inside of the formed dihedral corner reflector.

In addition, the outer side of the flat radio-reflective plate is covered with thin-film photoelectric converters.

In addition, the flat radio-reflecting plate is equipped with a mechanical device for fixing the open position.

In addition, the faces of the direct prism of the spacecraft hull, which do not have a radio-reflecting surface, are coated with photoelectric converters.

In addition, the European navigation system Galileo, or the Galileo system in conjunction with the GLONASS or GPS navigation systems are used as the consumer’s navigation equipment to determine the position of the center of mass of the spacecraft relative to the calibrated radar station.

In addition, the opening mechanism of the flat radio-reflecting plate is made of elastic tape.

The proposed spacecraft for radar calibration is illustrated by the drawings of FIG. 1 - FIG. 6.

FIG. 1 is a general view of a spacecraft with a body in the form of a direct prism, one of the faces of which has a radio-reflecting surface, and a flat rectangular plate of radio-reflecting material in the working (orbital) position.

FIG. 2 is a top view of a spacecraft with a flat radio-reflecting plate 3, where 4 is a disclosure mechanism; 6 - swivel; 7 is a mechanical device for fixing the open position of a flat radio-reflecting plate.

FIG. 3 is a top view of the spacecraft in the transport position before launching into orbit around the Earth, where 4 is the disclosure mechanism; 5 - fixation unit to the face of the direct prism of the spacecraft; 6 - swivel.

In FIG. 4 is a block diagram of an informational relationship of command line equipment, an on-board computer system, consumer navigation equipment, a microcontroller, an orientation and stabilization system interface unit and a fixing unit, comprising:

- command radio equipment (AKRL);

- microcontroller (MK);

- On-board computer system (BVS);

- consumer navigation equipment (NAP);

- interface unit (BS);

- orientation and stabilization system (SOIS);

- fixing unit (UV).

The information interconnection between the command radio line equipment, the on-board computer system, the consumer navigation equipment, the microcontroller, the orientation and stabilization system interface unit and the fixation unit is carried out via information exchange lines (indicated by a thin solid line in the drawing).

ACRL input and output are informationally connected to the BVS. The NAP output is connected to the first input of the on-board computer system, the first output of the on-board computer system is connected to the first input of the microcontroller, the first output of the microcontroller is connected to the first input of the BS, the first output of the BS is connected to the SOIS input. The SOIS output is connected to the second input of the BS, the second output of the BS is connected to the second input of the microcontroller, the second output of the microcontroller is connected to the second input of the onboard computer system, which controls the process of orientation of the spacecraft relative to the calibrated radar. The third output of the on-board computer system is connected to the third input of the microcontroller, the third output of the microcontroller is connected to the third input of the BS, the third output of the BS is connected to the UV input.

FIG. 5 is the relative position of the spacecraft and the calibrated radar after the disclosure of a flat radio-reflecting plate, where 8 is the bisector of the angle of the dihedral angular reflector formed by a flat radio-reflecting plate together with the radio-reflecting surface of the face of the direct prism of the spacecraft’s hull; 9 - the main lobe of the scattering indicatrix of the formed corner reflector; 10 - maximum of the main lobe of the scattering indicatrix formed by the RO; 11 - line of sight calibrated radar 12.

FIG. 6 is a diagram of a radar calibration session, where 8 is the bisector of the angle of the dihedral angle reflector formed by a flat radio-reflecting plate together with the radio-reflecting surface of the face of the direct prism of the spacecraft; 11 - line of sight calibrated radar 12; 10 is the maximum of the main lobe of the scattering indicatrix of the UO formed by a flat radio-reflecting plate together with the radio-reflecting surface of the face of the direct prism of the spacecraft’s hull.

The proposed spacecraft for calibrating a radar station contains a housing made in the form of a direct prism 1, one of the faces of which has a radio-reflecting surface 2 (see Fig. 1). Inside the spacecraft’s hull, there is an instrument compartment, a propulsion system, orientation and stabilization systems, command radio link equipment, an on-board computer system, GLONASS and / or GPS spacecraft navigation equipment, a microcontroller, an interface for the orientation and stabilization system, and a fixation unit with a microcontroller ( not shown in the drawing).

A flat rectangular plate is mounted on the side edge of the direct prism, pivotally connected to the spacecraft body so that the axis of rotation of the flat rectangular plate is parallel to the side edge of the direct prism. In this case, a flat rectangular plate of radio-reflecting material is deployed relative to the edge of a direct prism having a radio-reflecting surface, at an angle α, forming a dihedral corner reflector (see Fig. 1, Fig. 2).

The angle α is in the range from (90-Δ) degrees to (90 + Δ) degrees, where Δ is determined from the ratio:

0 <Δ <18 λ / a,

λ is the wavelength of the calibrated radar;

and - the size of the face of the corner reflector.

A flat rectangular plate of radio-reflecting material is equipped with an opening mechanism 4 and a fixing unit 5 to the spacecraft body (see Fig. 2, Fig. 3).

The functioning of the spacecraft for calibrating the radar according to the EPR value is as follows: for the time the spacecraft was put into orbit, a flat rectangular plate of radio-reflecting material was placed in the transport position and fixed so that it adjoins one of the faces of the direct prism of the spacecraft body (Fig. 3). Thus, the minimum space occupied by the spacecraft before being put into the target orbit is ensured.

After putting the spacecraft into the target orbit, the ground control complex with the command radio line and the onboard equipment of the spacecraft command radio line are used to control the spacecraft. Moreover, the coordinates of the radar station to be calibrated by the magnitude of the effective scattering surface are transmitted to the spacecraft from the ground control complex via a command radio link. Then, using the receivers of a navigation system of the GLONASS and / or GPS type and the on-board computer system, the current coordinates of the spacecraft's center of mass and the angles of the current spatial orientation of the spacecraft are determined. Using the on-board computer system, the position of the center of mass of the spacecraft relative to the coordinates of the calibrated radar station transmitted from the ground control complex is determined, as well as the orientation of the axes of the associated coordinate system of the spacecraft relative to the line of sight of the calibrated radar station. At the same time, the on-board computer system calculates and calculates the spatial position of the bisector of angle 8 of the dihedral angle reflector relative to the line of sight 11 of the calibrated radar station 12 at the current time. In the calculation, the coordinates (in the associated spacecraft coordinate system) of the middle of the rib and the position of the bisector of the angle of the dihedral angular reflector formed by a flat radio-reflecting plate together with the radio-reflecting surface of the face of the direct prism of the spacecraft’s hull are entered into the onboard computer system before the spacecraft is launched into orbit.

The calculated data from the first output of the on-board computer system are fed to the first input of the microcontroller, which forms control commands, which from the first output of the microcontroller go to the first input of the BS, and then from the first output of the BS arrive at the input of the SOIS. SOIS implements a spacecraft rotation and alignment of the angle bisector of the dihedral angle reflector with the line of sight of the calibrated radar station.

The SOIS output is connected to the second input of the BS, the second output of the BS is connected to the second input of the microcontroller, the second output of the microcontroller is connected to the second input of the onboard computer system, which controls the process of orientation of the spacecraft relative to the calibrated radar in real time.

When combining the position of the bisector of the angle of the dihedral angular reflector with the line of sight of the calibrated radar from the third output of the on-board computer system, a signal is transmitted to the third input of the microcontroller and converted from the third output of the microcontroller to the third input of the BS, and from the third output of the BS the signal goes to the UV input , as a result of UV triggering, a flat radio-reflecting plate is released from fixation to the spacecraft body and is opened using opening mechanisms, thus forming azom dihedral corner reflector (FIG. 5). The angle α between the faces of the corner reflector is in the range from (90-Δ) degrees to (90 + Δ) degrees, where Δ - is determined from the ratio:

0 <Δ <18 λ / a,

λ is the wavelength of the calibrated radar,

and - the size of the face of the corner reflector formed by the face of a direct prism having a radio-reflective surface, and a flat rectangular plate of radio-reflective material.

Then, using mechanical devices for fixing the open position, the flat radio-reflecting plates are rigidly fixed at a given angle a. At the same time, thin-film photoconverters glued to the back of flat radio-reflecting plates serve as an additional source of electric power for the spacecraft.

In the future, the information interaction of the onboard computer system, consumer navigation equipment, microcontroller, interface unit, spacecraft orientation and stabilization system ensures that the angle bisector of the formed dihedral angle reflector is kept aligned with the sight line of the calibrated radar station until the end of the radar calibration session, the coordinates of which were transmitted from the ground-based complex spacecraft control.

Moreover, the main lobe of the scattering indicatrix of a dihedral angular reflector formed by the face of a direct prism having a radio-reflecting surface and a flat rectangular plate of radio-reflecting material is directed to a calibrated radar station during the calibration session, and the maximum of the main lobe of the scattering indicatrix of a dihedral angular reflector coincides with the line of sight of the calibrated radar station.

Using a spacecraft, the structural elements of which form a dihedral angular reflector in the target orbit with faces turned at a given angle α in the range from (90-Δ) degrees to (90 + Δ) degrees, it is possible to achieve “flattening” of the shape of the main lobe of the scattering indicatrix of the corner reflector in the horizontal plane. Thus, the angle sector of the scattering indicatrix of the angular reflector in the horizontal plane, in which its EPR is almost constant, is 20 ° (± 10 °), [5] p. 150, fig. 4.7, curves 2, 3.

It should be noted that with an increase in the ESR of the reference reflector, the calibration efficiency increases [9] p. 65. So, as an example, the value of the ESR of the proposed spacecraft in the direction of the radar operating at a wavelength of 7 cm, taking into account a decrease in its value by 3 dB due to the deviation of the angle between the faces of the MA from the straight to “flatten” the shape of the main lobe, with the face of the corner reflector 100 cm, will be 2500 m ² , which is more than 800 times the EPR of a spherical reflector with a diameter of 200 cm [1] p. 49, table 2.1. 3. Such a size had the calibration spacecraft "South" as part of the RSC "Typhoon" [1] p. 49, [9] p. 65.

The use of the proposed spacecraft with a UO formed by the face of a direct prism having a radio-reflecting surface and a flat rectangular plate of radio-reflecting material and an angle α between them, set in a certain range of degrees, significantly improves the calibration conditions of existing and future radar tools. Thus, an increase in the EPR of the proposed spacecraft with SV more than 800-fold makes it possible to increase the range at which it is possible to calibrate the radar by the value of the EPR by 5.3 times in comparison with a spherical reflector with a diameter of 200 cm. This, in turn, will cause the spacecraft with MA, it will be stably observed at small elevation angles (3-5) degrees, at which it is necessary to calibrate high-potential early warning radars [1] p. 48.

In addition, a significant increase in the EPR of a calibration spacecraft will increase the orbit altitude of the launched spacecraft, which in turn will significantly increase its lifetime in orbit [1] p. 48.

Moreover, the application of the proposed spacecraft with UO will make it possible to calibrate the EPR value of high-potential radars in the operating mode with reduced radiation power (the so-called "energy-saving mode").

Thus, the proposed design of the spacecraft for calibrating the radar and the informational relationship between the equipment of the command radio line, the on-board computer system, the navigation equipment of the consumer, the microcontroller, the interface unit of the orientation and stabilization system of the spacecraft allows you to get properties that are different from the properties of known solutions, namely:

- conducting land and sea-based radar calibration sessions, the coordinates of which are transmitted from the ground-based spacecraft control complex;

- a highly efficient scattering surface (large EPR) due to the use of an angular reflector;

- a constant value of the EPR in the direction of the calibrated radar due to the orientation of the main lobe of the scattering indicatrix UO on the radar and preservation of the specified orientation during the calibration session.

Including the introduction of information lines of communication of the on-board computer system, NAP of the GLONASS and / or GPS space systems, a microcontroller, an interface unit with an orientation and stabilization system provides:

- determining the position of the center of mass of the spacecraft relative to the location of a given calibrated radar station;

- determination of the spatial position of the bisector of the angle of the dihedral corner reflector relative to the line of sight of the calibrated radar station at the current time;

- keeping using the spacecraft orientation and stabilization system of combining the bisector of the angle of the corner reflector with the line of sight of the calibrated radar station until the end of the calibration session.

As a result, the orientation of the maximum of the main lobe of the scattering indicatrix of the RS along the line of sight of the calibrated radar station is preserved and, therefore, the ESR value of the angular reflector in the direction of the radar is constant during the radar calibration session by the magnitude of the effective scattering surface.

With the accuracy of orientation and stabilization of the spacecraft no more than 0.5 degrees [1] p. 259, [6] p. 412, the change in the EPR of the spacecraft from the EO in the direction of the maximum of the main lobe of the EO scattering indicatrix does not exceed 0.5 dB, which will provide the required accuracy EPR measurements from the reflected signal no worse than 1 dB [1] p. 50.

This allows us to conclude that it is possible to use the proposed spacecraft for calibrating ground and sea-based radars operating on circular polarized waves with parallel reception of reflected signals, as well as calibrating the high-potential radar at small elevation angles (3-5) degrees and in the mode functioning with reduced radiation power (the so-called "energy-saving mode").

Information sources

1. Small spacecraft information support / ed. Fateeva V.F. M .: Radio engineering. 2010.S. 47-50, p. 259.

2. Leonov A.I., Leonov S.A., Nagulinko F.V. et al. Tests of the radar / ed. Leonova A.I. M .: Radio and communication. 1990.S. 37.

3. Missiles and spacecraft Design Bureau "South" / ed. Konyukhova S.N. Dnepropetrovsk. GKB "South" them. M.K. Yangel. 2000.S. 198-200.

4. Maisels E.N., Torgovanov V.A. Measurement of scattering characteristics of radar targets / ed. Kolosova M.A. M .: Soviet radio. 1972. S. 144-145, p. 193-194, p. 204-213.

5. Kobak V.O. Radar Reflectors / Ed. Leontievsky O.N. M .: Soviet radio. 1975.S. 103, p. 139, p. 144, p. 146, p. 150, p. 152, p. 235.

6. Bakitko R.V., Boldenkov E.N., Bulavsky N.T. and other GLONASS. The principles of construction and operation / ed. Perova A.I., Kharisova V.N. M .: Radio engineering. 2010.S. 412.

7. Maisenya L.I. Handbook of mathematics: basic concepts and formulas. Minsk: Ab. school 2011.S. 201-203.

8. Patent RU No. 2481248, 12/27/2011. Spacecraft with Reference Reflectors / Savelyev B.I. Open joint-stock company "Military-Industrial Corporation" Scientific-Production Association of Mechanical Engineering ".

9. Fateev V.F. A modern view of the development of the space echelon of EKO information tools. Aerospace defense. 2014. No1. S. 65.

Claims (11)

1. A spacecraft (SC) for calibrating radar stations (RLS), comprising a housing with an instrument compartment, a propulsion system, orientation and stabilization systems, solar panels, characterized in that the spacecraft housing is made in the form of a direct prism, one of the faces of which has a radio-reflective surface, and on the side edge of the direct prism a flat rectangular plate of radio-reflecting material is mounted pivotally connected to the spacecraft body so that the axis of rotation of the flat rectangular plate of radio-reflecting material is It is laid parallel to the side edge of the direct prism, while a flat rectangular plate of radio-reflective material is rotated relative to the face of the direct prism having a radio-reflective surface, at an angle α, forming a dihedral corner reflector, and the angle α is in the range from (90-Δ) degrees to ( 90 + Δ) degrees, where Δ - is determined from the ratio:
0 <Δ <18λ / a,
λ is the wavelength of the calibrated radar;
a is the face size of the corner reflector,
in addition, a flat rectangular plate of radio-reflecting material is equipped with an opening mechanism and a fixing unit to the direct prism of the spacecraft hull; additionally, command radio line equipment (AKRL), consumer navigation equipment (NAP) of the GLONASS and / or GPS space systems, on-board computing are introduced into the spacecraft system (BVS), a microcontroller, an interface unit for the orientation and stabilization system, and a fixation unit with a microcontroller, the ACRL input and output being informationally connected to the BVS, the NAP output is connected to the first BVV input, first the BVS output is connected to the first input of the microcontroller, the first output of the microcontroller is connected to the first input of the interface unit, the first output of the interface unit is connected to the input of the orientation and stabilization system, the output of the orientation and stabilization system is connected to the second input of the interface unit, the second output of the interface unit is connected to the second input microcontroller, the second output of the microcontroller is connected to the second input of the BVS, which controls the process of orientation of the spacecraft relative to the calibrated radar, in addition, the third output of the BVS under it is connected to the third input of the microcontroller, the third output of the microcontroller is connected to the third input of the interface unit, and the third output of the interface unit is connected to the input of the fixation unit of a flat rectangular plate of radio-reflecting material to the direct prism of the spacecraft body. 2. The spacecraft according to claim 1, characterized in that the flat rectangular plate of radio-reflecting material is arranged to unfold, while in the transport position it is laid and fixed so that it is adjacent to one of the faces of the direct prism, and deployed in the open position at an angle α relative to the face of a direct prism having a radio-reflecting surface. 3. The spacecraft according to claim 1, characterized in that the fixation unit of a flat rectangular plate of radio-reflecting material to the spacecraft body is made with an electromechanical system for checking and stripping. 4. The spacecraft according to claim 1, characterized in that the mechanism for opening the flat radio-reflecting plate is made, for example, in the form of a spring drive. 5. The spacecraft according to claim 1, characterized in that the face of the direct prism having a radio-reflective surface and a flat rectangular plate of radio-reflective material have the same dimensions. 6. The spacecraft under item 1, characterized in that the flat rectangular plate has a radio-reflective surface on the inside of the formed dihedral corner reflector. 7. The spacecraft according to claim 6, characterized in that the outer side of the flat radio-reflecting plate is covered with thin-film photoelectric converters. 8. The spacecraft according to claim 1, characterized in that the flat radio-reflecting plate is equipped with a mechanical device for fixing the open position. 9. The spacecraft according to claim 1, characterized in that the faces of the direct prism of the spacecraft’s hull, which do not have a radio-reflective surface, are coated with photoelectric converters. 10. The spacecraft according to claim 1, characterized in that the European navigation system Galileo, or the Galileo system in conjunction with the GLONASS or GPS navigation systems are used as the navigation equipment of the consumer to determine the position of the center of mass of the spacecraft relative to the calibrated radar station. 11. The spacecraft according to claim 4, characterized in that the opening mechanism of the flat radio-reflecting plate is made of an elastic tape.

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