Corner reflector assisted inter-satellite laser alignment method

Abstract

The invention discloses a corner reflector assisted inter-satellite laser alignment method, and belongs to the field of satellite laser communication. The device is used for realizing laser alignment between two satellites, the passive corner reflector is mounted on the mounting plane of the laser on the satellites, and the characteristic that the corner reflector can return incident light along the same path is utilized, so that the opposite satellite light beam is assisted to find the satellite. The invention provides an auxiliary means for inter-satellite laser alignment, can reduce the difficulty of laser alignment, and can be used in various inter-satellite laser terminals.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of satellite inter-satellite laser communication, and particularly to a method for inter-satellite laser alignment assisted by corner reflector, which is suitable for initial alignment of inter-satellite laser of double satellites and can reduce the difficulty of laser alignment. BACKGROUND

[0002] At present, with the vigorous development of communication satellite constellation, more than 7,000 satellites have been launched, and domestic communication constellation is also being fully laid out. In the vacuum space, the communication efficiency, weight and power consumption of laser are much better than those of microwave mode, so laser is generally used for inter-satellite networking communication. However, the beam of laser is narrow, and the distance between two satellites is generally more than 2000 km, which increases the difficulty of long-distance alignment of two satellites. In addition, due to the installation error of laser and satellite, satellite attitude error and other factors, the initial alignment of laser is also very difficult. SUMMARY

[0003] Therefore, the present application provides a method for inter-satellite laser alignment assisted by corner reflector. The method installs corner reflector and light return detector on the same installation surface of the inter-satellite laser terminal on the basis of the current inter-satellite laser terminal, so that the laser emitted by the opposite terminal can be automatically reflected, and the opposite satellite light return detector can find the accurate direction of the target satellite after receiving the reflected light return, thereby reducing the difficulty of two-way laser alignment.

[0004] The purpose of the present application is achieved as follows: A method for inter-satellite laser alignment assisted by corner reflector is used to realize the alignment between the inter-satellite laser terminals of two satellites, and each satellite is further provided with corner reflector and light return detector on the same installation surface of the inter-satellite laser terminal. The method comprises the following steps: Step 1: Before alignment, the position of the opposite satellite is informed to the two satellites through the ground station; Step 2: For one satellite, the scanning light is emitted through the transceiver lens of the inter-satellite laser terminal to find the opposite satellite in a certain area; Step 3: After the opposite satellite falls into the irradiation range of the scanning light, the corner reflector of the opposite satellite automatically reflects the light return to the satellite emitting the scanning light, and the light return detector of the satellite emitting the scanning light stops scanning after receiving the light return, thereby determining the specific position of the opposite satellite; After the specific positions of the opposite satellites are determined by the two satellites, the alignment is completed.

[0005] Further, for one of the two satellites, the emission wavelength of the transceiver lens of the inter-satellite laser terminal is , the receiving wavelength is , and the detection wavelength of the light return detector is ; For another satellite, the transmitting wavelength of the transmitting and receiving lens of the inter-satellite laser terminal is , the receiving wavelength is , and the detection wavelength of the light back detector is ; For each satellite, the error between the light back beam of the corner reflector and the incoming light beam is not more than 0.01°.

[0006] Compared with the background art, the present application has the following advantages: 1. In the conventional way, the inter-satellite laser alignment is bidirectional scanning, and after one party receives the incoming light of the other party, it transmits light back according to the direction of the incoming light. This has the problems of complexity of bidirectional cooperation and non-parallelism of the transmitting and receiving axes. The present application changes the bidirectional scanning to unidirectional scanning through the passive corner reflector, thereby reducing the complexity of the system.

[0007] 2. The present application uses the corner reflector to reflect the light back, and the corner reflector has high installation precision, and the reflected light can be strictly parallel to the incoming light, thereby improving the accuracy of reflection.

[0008] 3. The present application is unidirectional scanning, and one star can be used as a transmitting axis calibration target for another star. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is the principle block diagram of the alignment of two satellites in the embodiment of the present application.

[0010] Figure 2 is the working principle diagram of the inter-satellite laser terminal in the embodiment of the present application. DETAILED DESCRIPTION

[0011] In the following, the present application will be further described in detail in combination with the drawings.

[0012] A method for assisting inter-satellite laser alignment by a corner reflector is used to realize the alignment between the inter-satellite laser terminals of satellite 1 and satellite 2. As shown in Figure 1 , each satellite is also provided with a corner reflector and a light back detector on the same installation surface of the inter-satellite laser terminal. The specific steps of the alignment process are as follows: (1) The ground station 11 sends the position of satellite 6 to satellite 1 through the satellite-ground link, and sends the position of satellite 1 to satellite 6 through the satellite-ground link; (2) The transmitting and receiving lens 3 of the inter-satellite laser terminal 2 on satellite 1 generates a transmitting light beam 12, and controls the transmitting light beam 12 of the transmitting and receiving lens 3 to scan towards satellite 6 according to the position of satellite 1, the attitude of satellite 1, and the position information of satellite 6; (3) When the transmitting light beam 12 scans to satellite 6, the corner reflector 10 automatically reflects a light beam 15, and the reflected light beam 15 is parallel to the transmitting light beam 12; (4) The reflected beam 15 reaches satellite 1, and the backlight detector 4 receives the reflected beam 15 and generates an indication signal; (5) The inter-satellite laser terminal 2 controls the transmitting beam 12 of the transceiver lens 3 to stop scanning based on the indication signal generated by the backlight detector 4; (6) The inter-satellite laser terminal 2 determines the orientation of satellite 6 based on the current direction of the emitted beam 12.

[0013] Satellite 6 performs the same operation to determine the bearing of Satellite 1. Once both satellites have determined the bearing of each other, alignment is complete.

[0014] like Figure 2 As shown, the inter-satellite laser terminal 2 includes positioning information processing 2-1 and transmission scanning control 2-2. The operation of the inter-satellite laser terminal 2 is as follows: Positioning information processing 2-1 receives the local satellite attitude / position information, the installation angle of the inter-satellite laser terminal 2, and the position information of the six satellites provided by the satellite platform; Positioning Information Processing 2-1: Based on the attitude / position information of the satellite, the installation angle of the inter-satellite laser terminal 2, and the position information of the six satellites, calculate the theoretical angle (Θ, Ø) required for the transmitted light from the transceiver lens 3 to reach the corner reflector 10. (Θ, Ø) is represented in polar coordinates. Due to errors in satellite attitude, installation, and optical axis, the actual direction of the corner reflector 10 is ( , There is a deviation between the actual value (Θ, Ø) and the theoretical value (Θ, Ø). The transceiver lens 3 sets the scanning area and performs step-by-step coverage scanning within a certain area with (Θ, Ø) as the reference direction; When the transmitted light from transceiver lens 3 sweeps across ( , When the light is reflected back along its original path, the corner reflector 10 automatically reflects the reflected light back. When the reflected light detector 4 receives the reflected light, it sends a detection indication to the transmission scan control 2-2. The scan control 2-2 then stops the scan and records the current scan angle. , Feedback is sent to the location information processing unit 2-1; Location information processing 2-1 According to ( , (Θ, Ø) corrects for deviations caused by factors such as satellite attitude, installation error, and optical axis error.

[0015] The application adds passive device corner reflector on the existing inter-satellite laser terminal, through the characteristics of automatically returning the reflected incident light by the corner reflector, the reflected light is captured to assist the inter-satellite laser terminal to locate the position of the target star. In the case of large deviation of the target star attitude or position, the inter-satellite laser terminal scans the target star by one-way emission, and can quickly locate the position of the target star in a very short time after scanning the target star, therefore, a back light detector and a back light detection control program need to be added. In addition, the wavelength of the emitted light and the wavelength of the back light detection are consistent, so the isolation degree of the emitted light and the detection reception in the same star needs to be considered. When the two-way laser alignment is realized, the detector can be closed.

[0016] The application is used for realizing laser alignment between two satellites, a passive corner reflector is installed on the satellite in the installation plane of the laser, the corner reflector has the characteristics of returning the incident light, and the light beam of the opposite satellite is found. The application provides an auxiliary means for inter-satellite laser alignment, can reduce the difficulty of laser alignment, and can be used in various inter-satellite laser terminals.

Claims

1. A method of corner reflector assisted inter-satellite laser alignment for enabling alignment between inter-satellite laser terminals of two satellites, characterized in that, Each satellite is also equipped with an angle reflector and a light return detector on the same installation surface of its inter-satellite laser terminal, and the method comprises the following steps: Step 1: Before alignment, the position of the other satellite is first informed to the two satellites by a ground station; Step 2: For one satellite, a scanning light is emitted through the receiving and transmitting lens of the inter-satellite laser terminal to find the other satellite in a certain area; Step 3: After the other satellite falls into the irradiation range of the scanning light, the angle reflector of the other satellite automatically reflects the light back to the satellite emitting the scanning light, and the light return detector of the satellite emitting the scanning light stops scanning after receiving the light, thereby determining the specific position of the other satellite; After the two satellites both determine the specific position of the other satellite, the alignment is completed.

2. The method of claim 1, wherein, For one of the two satellites, the emission wavelength of the transmitting lens of the inter-satellite laser terminal is , the receiving wavelength is , and the detection wavelength of the light detector is ; For another satellite, the transmitting wavelength of the transmitting and receiving lens of the inter-satellite laser terminal is , the receiving wavelength is , and the detection wavelength of the light detection device is ; For each satellite, the error between the light return beam of the angle reflector and the incoming light beam is not more than 0.01°.

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