Inter-satellite laser communication load in-orbit receiving and transmitting optical axis coaxial self-calibration device and method thereof

Abstract

The invention discloses an inter-satellite laser communication load on-orbit receiving and transmitting optical axis coaxial self-calibration device and method, and belongs to the field of inter-satellite laser communication. Comprising a cube-corner prism, a coarse pointing mechanism, a beam expanding group lens, a color separation sheet, a fast reflecting mirror, a communication signal light emitting system, an optical filter, a light splitting sheet, an optical filter, a signal focusing mirror, a communication signal detector, a tracking focusing mirror and a tracking signal detector. Under the condition that beacon light is not used and a laser source is not additionally added, communication signal light is directly adopted to calculate and compensate the offset between the receiving optical axis and the transmitting optical axis through the cube-corner prism, the on-orbit alignment capture time is greatly shortened, and the cost, power consumption, size and weight of a self-calibration device are reduced.

Description

Technical Field

[0001] The present invention relates to the field of intersatellite laser communication, and more specifically, to an on-orbit coaxial self-calibration device and method for transmitting and receiving optical axes of an intersatellite laser communication payload. Background Art

[0002] Compared with traditional radio frequency communication technology, wireless laser communication technology has the advantages of high bandwidth, high transmission rate, low power consumption, no influence of electromagnetic frequency band, light equipment size and weight, strong anti-interception capability, etc., and has become one of the key technologies in the next generation of communication. Intersatellite laser communication is the best application scenario for wireless laser communication because there is no influence of atmospheric turbulence on the transmission link. It is very consistent with the current development trend and application needs of satellite communication lightweight and miniaturization, and has broad application prospects in the military and civilian fields of satellite communication networking.

[0003] In order to achieve lightweight manufacturing of intersatellite laser communication payloads and reduce the overall payload complexity, the optical path design of communication signal light transmission and reception with common aperture and no independent beacon light tracking has gradually become the mainstream application solution. The intersatellite laser communication payload with common aperture adopts the optical path structure design of parallel light transmission and parallel light reception, which is conducive to tracking and controlling the light beam and receiving communication. Therefore, the signal transmission optical axis, signal reception optical axis and tracking reception optical axis in the optical path system need to be kept parallel. However, during the process of launching from the ground to entering orbit, the satellite payload is affected by the impact and vibration generated by the thruster of the carrier rocket during launch, and the change of temperature of the optical path system, etc., which leads to an angle offset between the transmission optical axis and the receiving optical axis calibrated on the ground. For intersatellite laser communication payloads without independent beacon light, with a beam divergence of only tens of microradians and a communication distance of thousands of kilometers, a slight deviation in the parallelism of the receiving and transmitting optical axes will seriously affect the stability of the payload tracking and link establishment and the link communication performance, so it is necessary to control the parallelism between the receiving and transmitting optical axes within ten microradians (usually within one sixth of the beam divergence angle).

[0004] Existing coaxiality calibration technologies for the receiving and transmitting light axes of intersatellite laser communication payloads include: 1) coaxial self-calibration of the intersatellite laser communication payload with the ground optical station, and calculating the off-axis amount between the receiving and transmitting light axes for calibration. This type of calibration method is limited by weather and overhead time, has a long calibration cycle, and the entire calibration loop is complex, which affects the calibration efficiency; 2) on-orbit self-calibration of the intersatellite laser communication payload. Currently, the existing self-calibration methods are divided into: a) beacon light assisted calibration. The prior art CN202011291747.9 (An on-orbit self-calibration device for a space laser communication payload and its calibration method) uses a movable rotating shaft and beacon light in conjunction with a full-optical reflection prism for calibration. This method uses a conversion device to increase the complexity of the system, which is not conducive to the system Miniaturized integrated design; b) Beacon-free optical self-calibration. The prior art CN202210141497.3 (an on-orbit self-calibration device and calibration method for a satellite-borne laser communication device) uses an optical switch to switch the light transmitting and receiving circuits, and realizes calibration through a corner cube prism. This method uses a large-aperture corner cube prism to achieve total light reflection, and additional calibration lasers, optical switches and other devices are added, and the system design is complex; the prior art CN202310286368.8 (an on-orbit self-calibration device and method for a satellite-borne laser communication payload) needs to eliminate the chromatic aberration of the wavelengths of the transmitting and receiving light beams when using a transmission beam expansion system, and needs to scan the corner cube prism to return to the position of the maximum power of the receiving detector for calibration, and the software processing time is long. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an on-orbit coaxial self-calibration device and method for receiving and emitting light axes of an intersatellite laser communication payload. Under the premise of ensuring the coaxial self-calibration accuracy of the receiving and emitting light axes of the intersatellite laser communication payload, an on-orbit coaxial self-calibration device and method for receiving and emitting light axes of an intersatellite laser communication payload with a simple optical path system, low device complexity, simple software algorithm processing, and stable and reliable performance is designed and invented. The device and method can reasonably design and install a corner cube prism in the system without using beacon light and adding an additional laser source, and use communication signal light through the corner cube prism to calculate and compensate for the offset between the receiving and emitting light axes of the laser communication payload.

[0006] The object of the present invention is achieved through the following solutions:

[0007] An on-orbit coaxial self-calibration device for receiving and transmitting optical axes of an intersatellite laser communication payload, comprising:

[0008] Corner cube prism, coarse pointing mechanism, beam expander, color separation sheet, fast reflection mirror, communication signal light transmitting system, filter, beam splitter, filter, signal focusing mirror, communication signal detector, tracking focusing mirror and tracking signal detector;

[0009] After the signal light is emitted from the communication signal light transmitting system, it passes through the color separation plate, fast reflection mirror, beam expansion mirror group, and coarse pointing mechanism in sequence and is incident on the corner cube prism. Then, the incident light is reflected by the corner cube prism along the original path and passes through the coarse pointing mechanism, beam expansion mirror group, fast reflection mirror, color separation plate, and filter in sequence to reach the beam splitter. The beam splitter splits the laser into two beams, one of which is coupled into the communication signal detector through the signal focusing mirror, and the other is coupled into the tracking signal detector through the tracking focusing mirror. The communication signal detector is used to detect the received signal light power and perform communication processing. The tracking signal detector is used to collect the centroid of the received light spot and determine the tracking point position. The corner cube prism is installed on the intersatellite laser communication payload to ensure that the light beam emitted by the coarse pointing mechanism can be basically incident on the corner cube prism.

[0010] Furthermore, the light beam emitted from the coarse pointing mechanism is made incident on the corner cube prism to ensure that all the incident light beam is returned.

[0011] Furthermore, the light aperture of the corner cube prism is much smaller than the laser emission aperture, so that the aperture of the beam of incident light returning through the corner cube prism is very small, and the self-calibration point is obtained by calculating the centroid of the returned small-aperture beam.

[0012] Furthermore, the corner cube prism is a circular corner cube with a clear aperture of 6-12 mm, the clear aperture is smaller than the laser emission aperture, and the comprehensive angle difference is less than 2.5″.

[0013] Furthermore, the coarse pointing mechanism is specifically a two-dimensional swing mirror, an optical head, and a 45° reflector; the signal light is incident on the corner cube prism from the 45° reflector and the two-dimensional swing mirror of the coarse pointing mechanism, and after being reflected by the corner cube prism along the original path, it passes through the two-dimensional swing mirror and the 45° reflector of the coarse pointing mechanism in sequence and then enters the beam expander group mirror.

[0014] Furthermore, the beam expansion mirror assembly adopts a transmission-type beam expansion to form a transmitting and receiving common aperture optical antenna.

[0015] Furthermore, the beam expander lens group includes an off-axis reflective beam expander lens group or a coaxial reflective beam expander lens group.

[0016] Furthermore, the communication signal light transmitting system includes: a laser with spatial light output or a communication signal light transmitting system composed of a laser, an optical fiber, and a parabolic collimator. The light beam is generated by laser excitation, emitted through optical fiber coupling, and output to free space through off-axis reflection of the parabolic collimator.

[0017] Further, the communication signal detector includes an APD communication signal detector or a lens coupled to an optical fiber; the tracking signal detector includes a CCD tracking signal detector or a four-quadrant detector.

[0018] A method for self-calibrating the coaxial receiving and transmitting optical axis of an inter-satellite laser communication payload on-orbit, based on the above-mentioned self-calibrating device for self-calibrating the coaxial receiving and transmitting optical axis of an inter-satellite laser communication payload on-orbit, comprises the following steps:

[0019] Step S1: Use a collimator to complete the coaxiality calibration of the receiving and light axes to obtain the tracking point position P; adjust the direction of the coarse pointing mechanism so that the light beam emitted by the intersatellite laser communication payload is incident on the collimator in parallel; at this time, the parallel light beam emitted by the collimator passes through the receiving optical path of the intersatellite laser communication payload and is incident on the tracking signal detector, and the centroid of the light spot is the calibrated tracking point position P; when the centroid of the light spot of the receiving light beam is located at the calibrated tracking point position, the receiving and light axes are parallel to each other;

[0020] Step S2: Use a corner cube prism to complete the coaxial self-calibration of the receiving and transmitting light axis to obtain the self-calibration point Q; set the initial parameters of the coaxial self-calibration device of the receiving and transmitting light axis of the intersatellite laser communication payload, including setting the fast reflection mirror to the zero position; determine the power value of the light beam emitted by the intersatellite laser communication payload, so that the power returned to the tracking signal detector through the corner cube prism exceeds the threshold value, and the centroid of its light spot can be accurately calculated; adjust the direction of the coarse pointing mechanism so that the light beam emitted by the intersatellite laser communication payload is incident on the corner cube prism on the payload, and the light beam passes through the corner cube prism and the receiving optical path of the intersatellite laser communication payload to be received by the tracking signal detector, and the centroid of the light spot is called the self-calibration point Q; continue to adjust the direction of the coarse pointing mechanism so that the positions of the self-calibration point Q and the tracking point P coincide, and record the pointing position parameters of the coarse pointing mechanism at this time;

[0021] Step S3: Complete the on-orbit coaxial calibration of the receiving and light-axis according to the pointing position parameters of the coarse pointing mechanism calibrated in step S2; the coaxiality of the receiving and light-axis changes after being affected by the mechanical and thermal factors during the launch into orbit process; adjust the pointing direction of the coarse pointing mechanism to the position calibrated in step S2, obtain the on-orbit self-calibration point through the corner cube prism, set it as the tracking point for the on-orbit operation of the intersatellite laser communication payload, and realize the on-orbit coaxial calibration of the receiving and light-axis.

[0022] The beneficial effects of the present invention include:

[0023] The present invention directly uses communication signal light through a corner cube prism to calculate and compensate for the offset between the receiving and transmitting light axes without using beacon light and adding an additional laser source, thereby greatly reducing the on-orbit alignment and capture time and reducing the cost, power consumption, and volume and weight of the self-calibration device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 Schematic diagram of the structure of the device in the embodiment of the present invention. DETAILED DESCRIPTION

[0026] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0027] The specific implementation process of the present invention is as follows:

[0028] As a preferred embodiment of the present invention, the purpose of this embodiment is to address the deficiencies of the prior art methods and provide an on-orbit coaxial self-calibration device for the receiving and transmitting light axes of an inter-satellite laser communication payload. Without using beacon light and adding an additional laser source, the communication signal light is directly used through a corner cone prism to calculate and compensate for the offset between the receiving and transmitting light axes.

[0029] Specifically, if Figure 1 As shown, an on-orbit receiving and transmitting optical axis coaxial self-calibration device for an intersatellite laser communication payload includes: a corner cone prism, a coarse pointing mechanism (optical machine head, a two-dimensional swing mirror, a 45° reflector), a beam expander group mirror, a MEMS (Micro-electromechanical System) fast reflection mirror, a color separation plate, a parabolic collimator, an optical fiber, a laser, a filter, a spectrometer, a signal focusing mirror, an APD (Action Potential Duration) communication signal detector, a tracking focusing mirror, and a CCD (Charge Coupled Device) tracking signal detector.

[0030] Among them, the signal light is excited from the laser, passes through the optical fiber, and then passes through the color separator, MEMS fast mirror, beam expander, 45° mirror, and two-dimensional swing mirror to enter the corner cube prism. Then the incident light is reflected by the corner cube prism along the original path, and passes through the two-dimensional swing mirror, 45° mirror, beam expander, MEMS fast mirror, color separator, and filter to reach the beam splitter. The beam splitter divides the laser into two beams, one of which is coupled into the APD communication signal detector through the signal focusing mirror, and the other is coupled into the CCD tracking signal detector through the tracking focusing mirror. The APD communication signal detector is used to detect the received signal light power and perform communication processing; the CCD tracking signal detector is used to collect the centroid of the received light spot and determine the tracking point position.

[0031] Among them, the corner cube is installed on the intersatellite laser communication payload to ensure that the light beam emitted by the coarse pointing mechanism can basically be incident on the corner cube; optionally, the corner cube uses a circular corner cube with a clear aperture of 6-12mm, and its clear aperture is much smaller than the laser emission aperture, and the comprehensive angle difference is less than 2.5". The effective reflection area of ​​the corner cube decreases with the increase of the incident angle (the angle between the incident light and the normal line perpendicular to the incident surface), so the light beam emitted from the coarse pointing mechanism is made to be incident on the corner cube as much as possible to ensure that the incident light beam is fully returned. The clear aperture of the corner cube is much smaller than the laser emission aperture, so that the aperture of the light beam returned by the incident light through the corner cube is very small, and the self-calibration point is obtained by calculating the centroid of the returned small-aperture light beam. Since the aperture of the light beam returned through the corner cube is small, the centroid deviation of the light beam is very small when the angle incident on the corner cube changes within a small range, which can meet the high-precision test requirements.

[0032] The coarse pointing mechanism is specifically a two-dimensional swing mirror, an optical head, and a 45° reflector.

[0033] Among them, the beam expansion mirror group adopts a transmission-type beam expansion to form an optical antenna with a common aperture for transmission and reception, and chromatic aberration will occur when the transmission light beam and the receiving light beam of different wavelengths pass through the transmission-type beam expansion system. The intersatellite laser communication payload in-orbit coaxial self-calibration device for transmitting and receiving light axes proposed in this embodiment does not need to deliberately eliminate chromatic aberration. After two light beams of different wavelengths are incident on the coarse pointing mechanism at the same angle, they pass through the beam expansion mirror group and reach the CCD tracking signal detector. Although the centroid positions of the light spots are different, the angle difference between the two beams of light is unchanged. Optionally, this beam expansion mirror group can be replaced with an off-axis reflective type or a coaxial reflective type. In this case, there will be no influence of chromatic aberration, but the volume of the optical path system will be increased.

[0034] The laser, optical fiber, and parabolic collimator constitute a communication signal light transmission system, wherein the light beam is excited by the laser, emitted through optical fiber coupling, and output to free space through off-axis reflection of the parabolic collimator. Optionally, the communication signal light transmission system can be replaced by a laser with spatial light output.

[0035] The APD communication signal detector and CCD tracking signal detector respectively detect the received signal optical power and perform communication processing, collect the centroid of the received light spot and determine the tracking point position. The communication signal detector can be replaced by a lens coupled to the optical fiber; the tracking signal detector can be replaced by a four-quadrant detector.

[0036] As another preferred embodiment of the present invention, a method for self-calibration of the on-orbit optical and optical coaxial transmission of an inter-satellite laser communication payload is specifically provided, comprising the following steps:

[0037] Step S1: Use a collimator to complete the coaxiality calibration of the receiving and receiving light axes to obtain the tracking point position P. Adjust the direction of the coarse pointing mechanism so that the light beam emitted by the intersatellite laser communication payload is incident on the collimator in parallel, that is, the center of mass of the light spot of the payload is located at the center of the beam quality analyzer of the collimator; at this time, the parallel light beam emitted by the collimator passes through the receiving optical path of the intersatellite laser communication payload and is incident on the CCD tracking signal detector, and the center of mass of the light spot is the calibrated tracking point position P. Because it is an optical system with a common aperture for transmission and reception, the receiving and receiving light axes are parallel to each other when the center of mass of the light spot of the receiving light beam is located at the calibrated tracking point position.

[0038] Step S2: Use a corner cube prism to complete the coaxial self-calibration of the receiving and light axis, and obtain the self-calibration point position Q. Set the initial parameters of the coaxial self-calibration device of the receiving and light axis of the intersatellite laser communication payload, including setting the MEMS fast reflection mirror to zero position, which is equivalent to a reflector in a fixed position; determine the power value of the light beam emitted by the intersatellite laser communication payload, so that the power returned to the CCD tracking signal detector through the corner cube prism exceeds a certain threshold, and its spot centroid can be accurately calculated. Adjust the direction of the coarse pointing mechanism so that the light beam emitted by the intersatellite laser communication payload is incident on the corner cube prism on the payload, and the light beam passes through the corner cube prism and the receiving optical path of the intersatellite laser communication payload and is received by the CCD tracking receiving detector. The spot centroid is called the self-calibration point Q; continue to adjust the direction of the coarse pointing mechanism so that the positions of the self-calibration point Q and the tracking point P coincide, and record the pointing position parameters of the coarse pointing mechanism at this time.

[0039] Step S3: Complete the on-orbit coaxial calibration of the receiving and transmitting light axis according to the pointing position parameters of the coarse pointing mechanism calibrated in step S2. After being affected by the mechanical and thermal factors during the launch into orbit process, the coaxiality (tracking point position) of the receiving and transmitting light axis changes. Adjust the pointing direction of the coarse pointing mechanism to the position calibrated in step S2, obtain the on-orbit self-calibration point through the corner cube prism, and set it as the tracking point for the on-orbit operation of the intersatellite laser communication payload to achieve the on-orbit coaxial calibration of the receiving and transmitting light axis.

[0040] In summary, the present invention provides an on-orbit coaxial self-calibration device and method for the receiving and transmitting optical axes of an intersatellite laser communication payload, which uses a corner cube prism to reflect the outgoing light beam back to the receiving optical path of the payload by adjusting the pointing position of the coarse pointing mechanism, thereby coaxially calibrating the transmitting optical path and the receiving optical path in the optical system. This method does not require the cooperation of ground optical stations or other on-orbit intersatellite laser communication payloads to achieve on-orbit coaxial calibration of the receiving and transmitting optical axes, nor does it require additional lasers and beacon lights to assist in calibration. Calibration can be completed using signal lasers, which greatly reduces the on-orbit alignment and capture time of the intersatellite laser communication payload, and reduces the cost, power consumption, and volume and weight of the self-calibration device.

[0041] It should be noted that within the scope of protection defined in the claims of the present invention, the following embodiments can be combined and / or expanded or replaced in any logical way from the above specific implementation methods, such as disclosed technical principles, disclosed technical features or implicitly disclosed technical features.

[0042] Example 1

[0043] An on-orbit coaxial self-calibration device for receiving and transmitting optical axes of an intersatellite laser communication payload, comprising:

[0044] Corner cube prism, coarse pointing mechanism, beam expander, color separation sheet, fast reflection mirror, communication signal light transmitting system, filter, beam splitter, filter, signal focusing mirror, communication signal detector, tracking focusing mirror and tracking signal detector;

[0045] After the signal light is emitted from the communication signal light transmitting system, it passes through the color separation plate, fast reflection mirror, beam expansion mirror group, and coarse pointing mechanism in sequence and is incident on the corner cube prism. Then, the incident light is reflected by the corner cube prism along the original path and passes through the coarse pointing mechanism, beam expansion mirror group, fast reflection mirror, color separation plate, and filter in sequence to reach the beam splitter. The beam splitter splits the laser into two beams, one of which is coupled into the communication signal detector through the signal focusing mirror, and the other is coupled into the tracking signal detector through the tracking focusing mirror. The communication signal detector is used to detect the received signal light power and perform communication processing. The tracking signal detector is used to collect the centroid of the received light spot and determine the tracking point position. The corner cube prism is installed on the intersatellite laser communication payload to ensure that the light beam emitted by the coarse pointing mechanism can be basically incident on the corner cube prism.

[0046] Example 2

[0047] On the basis of Example 1, the light beam emitted from the coarse pointing mechanism is made incident on the corner cube prism to ensure that all the incident light beams are returned.

[0048] Example 3

[0049] Based on Example 1, the clear aperture of the corner cube prism (6-12mm) is much smaller than the laser emission aperture (usually 30-200mm), so that the aperture of the beam returned by the incident light through the corner cube prism is very small (6-12mm), and the self-calibration point is obtained by calculating the centroid of the returned small-aperture beam.

[0050] Example 4

[0051] On the basis of Example 1, the corner cube prism is a circular corner cube with a clear aperture of 6-12 mm, the clear aperture is smaller than the laser emission aperture, and the comprehensive angle difference is less than 2.5″.

[0052] Example 5

[0053] Based on Example 1, the coarse pointing mechanism is specifically a two-dimensional swing mirror, an optical head, and a 45° reflector; the signal light is incident on the corner cube prism from the 45° reflector and the two-dimensional swing mirror of the coarse pointing mechanism, and after being reflected by the corner cube prism along the original path, it passes through the two-dimensional swing mirror and the 45° reflector of the coarse pointing mechanism in turn and then enters the beam expansion group mirror.

[0054] Example 6

[0055] Based on Example 1, the beam expansion mirror assembly adopts a transmission-type beam expansion to form a transmitting and receiving common aperture optical antenna.

[0056] Example 7

[0057] Based on Example 1, the beam expander group lens includes an off-axis reflective beam expander group lens or a coaxial reflective beam expander group lens.

[0058] Example 8

[0059] Based on Example 1, the communication signal light transmission system includes: a laser with spatial light output or a communication signal light transmission system composed of a laser, an optical fiber, and a parabolic collimator. The light beam is generated by laser excitation and emitted through optical fiber coupling, and is output to free space through off-axis reflection from the parabolic collimator.

[0060] Example 9

[0061] Based on Example 1, the communication signal detector includes an APD communication signal detector or a lens coupled to an optical fiber; the tracking signal detector includes a CCD tracking signal detector or a four-quadrant detector.

[0062] Example 10

[0063] A method for self-calibrating the coaxial receiving and transmitting optical axis of an inter-satellite laser communication payload on-orbit, based on the above-mentioned self-calibrating device for self-calibrating the coaxial receiving and transmitting optical axis of an inter-satellite laser communication payload on-orbit, comprises the following steps:

[0064] Step S1: Use a collimator to complete the coaxiality calibration of the receiving and light axes to obtain the tracking point position P; adjust the direction of the coarse pointing mechanism so that the light beam emitted by the intersatellite laser communication payload is incident on the collimator in parallel; at this time, the parallel light beam emitted by the collimator passes through the receiving optical path of the intersatellite laser communication payload and is incident on the tracking signal detector, and the centroid of the light spot is the calibrated tracking point position P; when the centroid of the light spot of the receiving light beam is located at the calibrated tracking point position, the receiving and light axes are parallel to each other;

[0065] Step S2: Use a corner cube prism to complete the coaxial self-calibration of the receiving and transmitting light axis to obtain the self-calibration point Q; set the initial parameters of the coaxial self-calibration device of the receiving and transmitting light axis of the intersatellite laser communication payload, including setting the fast reflection mirror to the zero position; determine the power value of the light beam emitted by the intersatellite laser communication payload, so that the power returned to the tracking signal detector through the corner cube prism exceeds the threshold value, and the centroid of its light spot can be accurately calculated; adjust the direction of the coarse pointing mechanism so that the light beam emitted by the intersatellite laser communication payload is incident on the corner cube prism on the payload, and the light beam passes through the corner cube prism and the receiving optical path of the intersatellite laser communication payload to be received by the tracking signal detector, and the centroid of the light spot is called the self-calibration point Q; continue to adjust the direction of the coarse pointing mechanism so that the positions of the self-calibration point Q and the tracking point P coincide, and record the pointing position parameters of the coarse pointing mechanism at this time;

[0066] Step S3: Complete the on-orbit coaxial calibration of the receiving and light-axis according to the pointing position parameters of the coarse pointing mechanism calibrated in step S2; the coaxiality of the receiving and light-axis changes after being affected by the mechanical and thermal factors during the launch into orbit process; adjust the pointing direction of the coarse pointing mechanism to the position calibrated in step S2, obtain the on-orbit self-calibration point through the corner cube prism, set it as the tracking point for the on-orbit operation of the intersatellite laser communication payload, and realize the on-orbit coaxial calibration of the receiving and light-axis.

[0067] The units involved in the embodiments of the present invention may be implemented by software or hardware, and the units described may also be arranged in a processor. The names of these units do not, in some cases, limit the units themselves.

[0068] According to one aspect of an embodiment of the present invention, a computer program product or a computer program is provided, the computer program product or the computer program includes a computer instruction, and the computer instruction is stored in a computer-readable storage medium. A processor of a computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the method provided in the above various optional implementations.

[0069] As another aspect, an embodiment of the present invention further provides a computer-readable medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements the method described in the above embodiment.

Claims

1. An on-orbit coaxial self-calibration device for receiving and transmitting optical axes of intersatellite laser communication payload, characterized in that: include: Corner cube prism, coarse pointing mechanism, beam expander, color separation sheet, fast reflection mirror, communication signal light transmitting system, filter, beam splitter, filter, signal focusing mirror, communication signal detector, tracking focusing mirror and tracking signal detector; After the signal light is emitted from the communication signal light transmitting system, it passes through the color separation plate, fast reflection mirror, beam expansion mirror group, and coarse pointing mechanism in sequence and is incident on the corner cube prism. Then, the incident light is reflected by the corner cube prism along the original path and passes through the coarse pointing mechanism, beam expansion mirror group, fast reflection mirror, color separation plate, and filter in sequence to reach the beam splitter. The beam splitter splits the laser into two beams, one of which is coupled into the communication signal detector through the signal focusing mirror, and the other is coupled into the tracking signal detector through the tracking focusing mirror. The communication signal detector is used to detect the received signal light power and perform communication processing. The tracking signal detector is used to collect the centroid of the received light spot and determine the tracking point position. The corner cube prism is installed on the intersatellite laser communication payload to ensure that the light beam emitted by the coarse pointing mechanism can be basically incident on the corner cube prism.

2. The on-orbit optical coaxial self-calibration device for inter-satellite laser communication payload according to claim 1 is characterized in that: The light beam emitted from the coarse pointing mechanism is made incident on the corner cube prism to ensure that the incident light beam is completely returned.

3. The on-orbit optical coaxial self-calibration device for inter-satellite laser communication payload according to claim 1 is characterized in that: The light aperture of the corner cube prism is much smaller than the laser emission aperture, so that the aperture of the beam of incident light returning through the corner cube prism is very small, and the self-calibration point is obtained by calculating the centroid of the returned small-aperture beam.

4. The on-orbit optical coaxial self-calibration device for inter-satellite laser communication payload according to claim 1 is characterized in that: The corner cube prism is a circular corner cube with a light aperture of 6-12 mm, the light aperture is smaller than the laser emission aperture, and the comprehensive angle difference is less than 2.5″.

5. The on-orbit optical coaxial self-calibration device for inter-satellite laser communication payload according to claim 1 is characterized in that: The coarse pointing mechanism specifically comprises a two-dimensional swing mirror, an optical head, and a 45° reflector; the signal light is incident on the corner cube prism from the 45° reflector and the two-dimensional swing mirror of the coarse pointing mechanism, and after being reflected by the corner cube prism along the original path, it passes through the two-dimensional swing mirror and the 45° reflector of the coarse pointing mechanism in sequence and then enters the beam expander group mirror.

6. The on-orbit optical coaxial self-calibration device for inter-satellite laser communication payload according to claim 1 is characterized in that: The beam expansion mirror assembly adopts transmission-type beam expansion to form a transmitting and receiving common aperture optical antenna.

7. The on-orbit optical coaxial self-calibration device for inter-satellite laser communication payload according to claim 1 is characterized in that: The beam expander group lens comprises an off-axis reflective beam expander group lens or a coaxial reflective beam expander group lens.

8. The on-orbit optical coaxial self-calibration device for inter-satellite laser communication payload according to claim 1 is characterized in that: The communication signal light emission system includes: a laser with spatial light output or a communication signal light emission system composed of a laser, an optical fiber, and a parabolic collimator. The light beam is excited by the laser, emitted through optical fiber coupling, and output to free space through off-axis reflection of the parabolic collimator.

9. The on-orbit optical coaxial self-calibration device for inter-satellite laser communication payload according to claim 1 is characterized in that: The communication signal detector includes an APD communication signal detector or a lens coupled to an optical fiber; the tracking signal detector includes a CCD tracking signal detector or a four-quadrant detector.

10. A method for self-calibration of the on-orbit optical coaxial receiving and transmitting optical axis of an intersatellite laser communication payload, characterized in that: The on-orbit coaxial self-calibration device for receiving and transmitting optical axes of inter-satellite laser communication payload according to claim 1 comprises the following steps: Step S1: Use a collimator to complete the coaxiality calibration of the receiving and light axes to obtain the tracking point position P; adjust the direction of the coarse pointing mechanism so that the light beam emitted by the intersatellite laser communication payload is incident on the collimator in parallel; at this time, the parallel light beam emitted by the collimator passes through the receiving optical path of the intersatellite laser communication payload and is incident on the tracking signal detector, and the centroid of the light spot is the calibrated tracking point position P; when the centroid of the light spot of the receiving light beam is located at the calibrated tracking point position, the receiving and light axes are parallel to each other; Step S2: Use a corner cube prism to complete the coaxial self-calibration of the receiving and transmitting light axis to obtain the self-calibration point Q; set the initial parameters of the coaxial self-calibration device of the receiving and transmitting light axis of the intersatellite laser communication payload, including setting the fast reflection mirror to the zero position; determine the power value of the light beam emitted by the intersatellite laser communication payload, so that the power returned to the tracking signal detector through the corner cube prism exceeds the threshold value, and the centroid of its light spot can be accurately calculated; adjust the direction of the coarse pointing mechanism so that the light beam emitted by the intersatellite laser communication payload is incident on the corner cube prism on the payload, and the light beam passes through the corner cube prism and the receiving optical path of the intersatellite laser communication payload to be received by the tracking signal detector, and the centroid of the light spot is called the self-calibration point Q; continue to adjust the direction of the coarse pointing mechanism so that the positions of the self-calibration point Q and the tracking point P coincide, and record the pointing position parameters of the coarse pointing mechanism at this time; Step S3: Complete the on-orbit coaxial calibration of the receiving and light-axis according to the pointing position parameters of the coarse pointing mechanism calibrated in step S2; the coaxiality of the receiving and light-axis changes after being affected by the mechanical and thermal factors during the launch into orbit process; adjust the pointing direction of the coarse pointing mechanism to the position calibrated in step S2, obtain the on-orbit self-calibration point through the corner cube prism, set it as the tracking point for the on-orbit operation of the intersatellite laser communication payload, and realize the on-orbit coaxial calibration of the receiving and light-axis.

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