CN104267390A - Lag angle compensation device and lag angle compensation precision correction method of satellite-borne wind-detecting laser radar system - Google Patents

Abstract

The invention relates to a lag angle compensation device and an accuracy correction method of a spaceborne laser radar wind measurement system, and belongs to the field of measurement technology. The lag angle compensation module in the device of the present invention is located behind the dual-telescope scanning optical system; when the system is working normally, the echo laser is transmitted to the lag angle compensation module through the dual-telescope scanning optical system, and then transmitted to peripheral equipment after being compensated by the lag angle compensation module ; When correcting the lag angle compensation accuracy, the movable plug-in mirror is located on the optical path behind the lag angle compensation module, and the beam expander is placed on one side of the movable plug-in mirror and at the front end of the area array photodetector; The output terminal of the area array photodetector is connected to the input terminal of the control signal processing module; the output terminal of the control signal processing module is connected to the input terminal of the lag angle compensation module. The invention relates to a lag angle compensation device and accuracy correction method for a space-borne wind measurement laser radar system, which has the advantages of dynamically adjustable compensation angle, accurate correction by closed-loop detection, and the like.

Description

Lag angle compensation device and precision correction method of spaceborne wind lidar system

technical field

The invention relates to a lag angle compensation device and an accuracy correction method, in particular to a lag angle compensation device and an accuracy correction method for a spaceborne laser radar wind measurement system, and belongs to the field of measurement technology. the

Background technique

Laser Doppler wind radar is a technology that uses the Doppler effect of light to measure the velocity of atmospheric wind field. It performs heterodyne beat frequency between the echo containing wind speed information and local oscillator light to calculate the wind speed at different distances. It has the characteristics of high sensitivity and high speed accuracy. It can measure clear air turbulence, wind shear, aircraft trajectory vortex, etc., in It has broad application prospects in fields such as weather forecasting, environmental monitoring, aerospace, remote sensing and telemetry, and meteorological observation. The orbital altitude of the satellite is hundreds of kilometers, and there is a time delay of milliseconds between launching the laser and receiving the echo signal, that is, the round-trip time from the laser pulse to the target. For the laser radar with coaxial transmission and reception, the high-speed movement of the satellite platform will cause the optical axis of the telescope to produce a deflection angle at the moment of receiving the signal relative to the moment of laser emission, which is called the lag angle. For space-borne wind-measuring lidar, although the composition of each system is different, the lag angle generated by the radar system can be calculated according to the position of the detection point and the speed and height of the platform, that is, the lag angle can be considered as known. The existence of the lag angle will reduce the receiving efficiency of the lidar. Since the echo signal is very weak, it is necessary to compensate the lag angle to improve the receiving efficiency. the

Wind lidar requires wind speed data detected in at least two directions, and vector synthesis is performed to obtain ground wind speed and wind direction information. In the wind lidar system seen in the open literature, most of the transmitting and receiving parts use a single telescope and a scanning controller. The function of the scanning mirror is to change the direction of light at different times (the angular velocity of the scanning mirror is a uniform rotation ), so that the lidar can detect the wind speed in multiple directions on the same measurement point, so as to obtain the wind direction and wind speed at the measurement point. For a wind-measuring LiDAR system with a scanning mirror, the scanning mirror will rotate to a certain position when the lag angle of the echo beam is generated, and the position of the echo light that finally enters the system can be calculated using optical principles. There are two methods of lag angle compensation. One is to add a position-adjustable lag angle compensation mirror to the system. When performing lag angle compensation, the compensation mirror is rotated to a fixed position, and the local oscillator light is adjusted. Compensation makes it reflected to the position of the echo light for heterodyne beat frequency; another method is to use a lag angle compensation mirror to compensate the echo optical axis to coincide with the local oscillator light. Since the lag angle is known, the lag angle compensation The reflector needs to be displaced to different fixed positions when compensating for different lag angles, and finally the compensated echo beam and local oscillator light are subjected to heterodyne beat frequency. the

The national invention patent "A Novel Coherent Wind LiDAR Telescope System" (patent application number: ) discloses a wind measurement LiDAR telescope system that uses a scan controller and two telescopes to scan. Its structure is shown in Figure 1. The wind-measuring lidar telescope system includes a scanning controller and two identical off-axis reflecting telescopes with a certain angle; the two off-axis reflecting telescopes are centered on the scanning controller (4) and placed at the same distance apart at a certain angle ; Each off-axis reflecting telescope is made up of primary mirror (1), secondary mirror (2) and compensating mirror (3); scanning controller (4) is made up of a scanning motor and a plane mirror; The deflection of the mirror is to switch the optical path of the two telescopes to realize the detection of the two telescopes; the light emitted from the laser light source is reflected by the mirror on the scanning motor and enters the compensation mirror (3) of the telescope, and then passes through the compensation mirror (3) It is refracted to the secondary mirror (2) of the telescope, and then reflected to the primary mirror (1) of the telescope through the tilted secondary mirror (2), and is emitted into the atmosphere by the primary mirror (1) of the telescope; as a carrier signal, the laser light is used as a carrier signal to communicate with molecules and gases in the atmosphere The interaction of sol particles generates echo signals, and the echo signals returned from the atmosphere are received by the same telescope, through the primary mirror (1), secondary mirror (2), and compensation mirror (3) of the telescope to the mirror on the scanning motor , reflected into the subsequent optical path. the

Due to the different working hours of the two off-axis reflecting telescopes, at a certain moment, only one telescope can detect the wind speed at the measurement point. Finally, the wind speed data detected in these two directions are vector synthesized to obtain the horizontal wind speed and wind direction information at the measurement point. The double-telescope scanning method will cause two types of offsets in the optical axis of the echo beam, that is, the optical axis of the echo beam is located above or below the theoretical optical axis of the receiving system, so that the lag angle cannot be compensated by a fixed device. Therefore, it is necessary to design a device and accuracy correction method for compensating the lag angle of the dual-telescope spaceborne wind lidar system. the

Contents of the invention

The object of the present invention is to propose a device and an accuracy correction method for compensating the lag angle of a spaceborne wind-measuring lidar system with two telescopes. On the basis of the existing lag angle compensation device using two light guide mirrors for compensation, the method of the present invention proposes a lag angle compensation device that can dynamically adjust the compensation angle and can be accurately corrected by closed-loop detection, and its precision correction method. The device of the invention detects the accuracy of the lag angle compensation by adding a photoelectric detector, and at the same time corrects the compensation effect of the lag angle through a control signal processing module. the

The purpose of the present invention is achieved through the following technical solutions. the

A lag angle compensation device for a spaceborne laser radar wind measurement system, characterized in that it includes: a telescope scanning optical system (5), a lag angle compensation module (6), a movable insertable reflector (7), a beam expander (8), an area array photodetector (9) and a control signal processing module (10). Symbol a represents the system optical axis of the lag angle compensation device of the spaceborne lidar wind measuring system. the

The telescope scanning optical system (5) includes a scanning controller (4) and two identical off-axis reflecting telescopes (represented by symbols W ₁ and W ₂ respectively); the optical axis of the off-axis reflecting telescope W ₁ is aligned with the star The system optical axis (indicated by symbol a) of the lag angle compensation device of the laser radar wind measuring system is parallel; the distances between the off-axis reflective telescopes W ₁ and W ₂ and the scanning controller (4) are equal, and the off-axis reflective telescope W ₁ It forms a certain angle with the connection line between W ₂ and the scan controller (4). Each off-axis reflecting telescope is made up of primary mirror (1), secondary mirror (2) and compensating mirror (3); scanning controller (4) is made up of a scanning motor and a plane mirror; The deflection of the mirror is used to switch the optical path of the two off-axis reflecting telescopes, and realize the detection of the two off-axis reflecting telescopes. The light emitted from the laser light source is reflected by the mirror on the scanning motor and enters the compensation mirror (3) of the off-axis reflection telescope, and then refracted to the secondary mirror (2) of the telescope through the compensation mirror (3), and then passes through the tilted secondary mirror (2) ) is reflected to the main mirror (1) of the off-axis reflecting telescope, and is emitted into the atmosphere by the main mirror (1) of the off-axis reflecting telescope; as a carrier signal, the laser interacts with molecules and aerosol particles in the atmosphere to generate an echo signal, which is transmitted from the atmosphere The echo signal returned in the center is received by the same off-axis reflecting telescope, passes through the main mirror (1), secondary mirror (2) and compensation mirror (3) of the off-axis reflecting telescope to the mirror on the scanning motor, and is reflected to the subsequent optical path middle.

The two off-axis reflecting telescopes W ₁ and W ₂ are in alternate working mode. After one of the off-axis reflecting telescopes completes m laser pulse detection, it switches to the other off-axis reflecting telescope; the value of m is preset by man, m∈ [20, 100].

The main functions of the telescope scanning optical system (5) are: ① emitting laser light and receiving echoes when the system is working normally; ② providing back-reflected light when performing precision correction on lag angle compensation. the

The lag angle compensation module (6) includes: a rotation compensator (601), a translation compensator (606), a rotation light guide mirror (603), a translation light guide mirror (604), a first connecting member (602) and a second Two connectors (605); the rotating light guide mirror (603) is fixedly connected to the rotation compensator (601) through the first connector (602); the translation light guide mirror (604) is connected to the translation compensation through the second connector (605) The device (606) is fixedly connected; in the initial state, the zero point positions of the rotating light guide mirror (603) and the translation light guide mirror (604) are placed in parallel and form an angle of 45° with the horizontal direction;

The functions of the lag angle compensation module (6) include: ① When the spaceborne lidar wind measurement system is working normally, perform lag angle compensation. ② When the spaceborne lidar wind measurement system is in the lag angle compensation accuracy correction stage, the lag angle compensation accuracy correction work is performed. the

The function of the movable plug-in reflector (7) is: when the spaceborne wind-measuring lidar system needs to correct the accuracy of lag angle compensation, the movable plug-in reflector (7) is moved into the optical path, and the movable plug-in reflector (7) The plug-in reflector (7) transmits the back-reflected light beam from the compensating mirror (3) in the off-axis reflecting telescope _W1 to the beam expander (8).

The function of the beam expander (8) is to reduce the diameter of the back-reflected optical signal beam of the compensation mirror (3) in the off-axis reflecting telescope _W1 by multiples, so as to adapt to the size of the area array detector. The multiples are optional

The function of the area array photodetector (9) is to receive the light spot in the beam expander (8), and transmit the image to the control signal processing module (10). the

The functions of the control signal processing module (10) include: 1. when the spaceborne wind measurement laser radar system is working normally, the control signal processing module (10) sends the upper lag angle compensation signal to the lag angle compensation module (6) or Downward lag angle compensation signal; Send movable insertable reflector (7) to move out signal to movable insertable reflector (7); Send closing signal to area array photodetector (9); And in off-axis reflective telescope W ₁ During normal operation, the control signal processing module (10) sends a move-out signal to the scan controller (4); when the off-axis reflecting telescope _W2 works normally, the control signal processing module (10) sends a move-in signal to the scan controller (4) . ② When the spaceborne wind-measuring lidar system is in the lag angle compensation accuracy correction stage, the control signal processing module (10) sends an accuracy correction signal to the lag angle compensation module (6); sends an accuracy correction signal to the movable plug-in mirror (7) The movable inserting mirror (7) moves in a signal; sends an opening signal to the area array photodetector (9); sends a moving out signal to the scanning controller (4).

The connection relationship of the above parts is as follows:

The lag angle compensation module (6) is located behind the dual-telescope scanning optical system (5); when the system is in normal operation, the echo laser is transmitted to the lag angle compensation module (6) through the dual-telescope scanning optical system (5), and after lag angle compensation The module (6) is compensated and transmitted to the peripheral equipment; when correcting the lag angle compensation accuracy, the movable plug-in reflector (7) is located on the optical path behind the lag angle compensation module (6), and the beam expander (8) is placed on the One side of the movable plug-in reflector (7) is positioned at the front end of the area array photodetector (9); the output terminal of the area array photodetector (9) is connected to the input end of the control signal processing module (10); the control signal The output terminal of the processing module (10) is connected to the input terminal of the lag angle compensation module (6). the

The working process of using the lag angle compensation device of the spaceborne wind measurement lidar system to compensate the lag angle is:

Step 1: Make the space-borne wind measurement laser radar system in the normal working stage, control the signal processing module (10) to send the movable plug-in reflector (7) to move out signal to the movable plug-in reflector (7), the movable The plug-in reflector (7) is moved out of the system optical path; the control signal processing module (10) sends a closing signal to the area array photodetector (9), and the area array photodetector (9) is closed; the control signal processing module (10) The working sequence between the off-axis reflecting telescope _W1 and _W2 , when the off-axis reflecting telescope _W1 is working normally, the control signal processing module (10) sends the scan controller (4) to move out signal, and the scan controller (4) moves out of the system Optical path: when the off-axis reflecting telescope W ₂ is working, the control signal processing module (10) sends the scanning controller (4) to move into the signal, and the scanning controller (4) moves into the system optical path.

Step 2: The control signal processing module (10) sends an upper lag angle compensation signal or a lower lag angle compensation signal to the lag angle compensation module (6). the

When the off-axis reflecting telescope _W1 in the telescope scanning optical system (5) works normally, the control signal processing module (10) sends an upper lag angle compensation signal.

When the off-axis reflecting telescope _W2 in the telescope scanning optical system (5) was working normally, the control signal processing module (10) sent the lag angle compensation signal below.

Step 3: The lag angle compensation module (6) completes the lag angle compensation work according to the upper lag angle compensation signal or the lower lag angle compensation signal sent by the control signal processing module (10). Specifically:

Step 3.1: When the lag angle compensation module (6) receives the upper lag angle compensation signal, the specific operation is: the rotation compensator (601) controls the rotation of the rotating light guide mirror (603) to the zero position, and then rotates clockwise to the initial position. The position is at the position of θ/2 degrees, where θ is the lag angle, θ is pre-set by humans, θ∈[9×10 ^-4 /π, 0.36/π] degrees; the translation compensator (606) controls the translation of the light guide mirror (604) Rotate to the zero position, and then translate H×tanθ to the right, where H is the distance from the focal point of the off-axis reflecting telescope W ₁ to the symmetrical center point of the rotating light guide mirror (603). After the rotation compensator (601) and the translation compensator (606) complete the control, the operation ends.

Step 3.2: When the lag angle compensation module (6) receives the lower lag angle compensation signal, the specific operation is: the rotation compensator (601) controls the rotation of the light guide mirror (603) to the zero position, and then rotates counterclockwise to the initial position. The position is at the position of θ/2 degrees; the translation compensator (606) controls the translation light guide mirror (604) to rotate to the zero position, and then translates H×tanθ to the left. After the rotation compensator (601), the translation compensator (606) and the scan controller (4) complete the control, the operation ends. the

The working process of using the lag angle compensation device of the spaceborne wind measurement lidar system to correct the lag angle accuracy is as follows:

Step a: Make the space-borne wind-measuring lidar system in the lag angle accuracy correction stage, control the signal processing module (10) to send the movable plug-in mirror (7) to move in signal to the movable plug-in mirror (7), The movable plug-in reflector (7) moves into the optical path of the system; the control signal processing module (10) sends an opening signal to the area array photodetector (9), and the area array photodetector (9) works normally; the control signal processing module (10 ) sends the scanning controller (4) moving out signal, the scanning controller (4) moves out of the system optical path, the control signal processing module (10) sends a reset command to the lag angle compensation module (6), and the rotating light guide mirror (603) and the translation guide Light mirror (604) resets to zero position;

Step b: Control the signal processing module (10) to read the back-reflected light spot image of the compensating mirror (3) in the off-axis reflecting telescope _W1 obtained by the area array photodetector (9), and calculate and obtain the area array photodetector (9) the difference (expressed in symbol ΔL) of the abscissa of the spot center that obtains and the central point of the area array photodetector (9); α/2, and the difference ΔL of the spot center obtained by the area photodetector (9) and the center point of the area photodetector (9) and the fine-tuning rotation amount α/2 are sent to the lag angle compensation module ( 6). The value of α can be calculated by formula (1).

ΔL·AF＝h·tanα (1)

Wherein, h is the distance from the symmetrical center point of the rotating light guide mirror (603) to the area photodetector (9), and AF is the beam expansion factor of the beam expander (8). the

Step c: the lag angle compensation module (6) completes the lag angle accuracy correction work; the specific operation is to detect whether the rotating light guide mirror (603) is at the zero position, if the spot center obtained by the area array photodetector (9) is consistent with the area array The difference ΔL of the abscissa of the central point of the photodetector (9), if |ΔL|<σ is established, σ is a preset threshold, σ∈[0,10] microns, then it is considered that the rotating light guide mirror (603) is in The zero position does not need to be compensated; otherwise, when ΔL is positive, the rotating compensator (601) controls the rotating light guide mirror (603) to rotate counterclockwise from the current position by α/2 degrees; when ΔL is negative, The rotation compensator (601) controls the rotation light guide mirror (603) to rotate α/2 degrees clockwise from the current position. Repeat step c until the detected |ΔL|<σ, stop the operation. the

Beneficial effect

The invention relates to a lag angle compensation device and accuracy correction method for a space-borne wind measurement laser radar system, which has the advantages of dynamically adjustable compensation angle, accurate correction by closed-loop detection, and the like. the

Description of drawings

Fig. 1 is the structural representation of a kind of wind measuring lidar telescope system in the prior art;

Among them: 1-primary mirror, 2-secondary mirror, 3-compensation mirror, 4-scanning controller. the

Fig. 2 is the structural representation of lagging angle compensating device of space-borne wind measuring lidar system in the specific embodiment of the present invention;

Among them, 5-telescope scanning optical system, 6-lag angle compensation module, 7-movable plug-in mirror, 8-beam expander, 9-area photodetector, 10-control signal processing module;

Fig. 3 is the structural representation of lag angle compensation module in the specific embodiment of the present invention;

Among them, 601-rotational compensator, 602-first connecting part, 603-rotating light guide mirror, 604-translational light guiding mirror, 605-second connecting part, 606-translational compensator. the

Detailed ways

In order to better illustrate the technical solution of the present invention, the present invention will be further described below through examples and accompanying drawings. the

The lag angle compensation device of the spaceborne wind-measuring lidar system in this embodiment has a structure as shown in Figure 1, which includes: a telescope scanning optical system 5, a lag angle compensation module 6, a movable plug-in reflector 7, a beam expander Mirror 8, area array photodetector 9 and control signal processing module 10. In Fig. 1, a represents the system optical axis of the lag angle compensation device of the spaceborne lidar wind measurement system. the

The telescope scanning optical system 5 includes: a scanning controller 4 and two identical off-axis reflecting telescopes W _{1 and} W ₂ ; The optical axis a of the system is parallel; the distances between the off-axis reflecting telescopes W ₁ and W ₂ and the scanning controller 4 are equal, and the connection between the off-axis reflecting telescopes W ₁ and W ₂ and the scanning controller 4 forms a certain angle. Each off-axis reflecting telescope is made up of main mirror 1, secondary mirror 2 and compensating mirror 3; scanning controller 4 is made up of a scanning motor and a plane reflecting mirror; by the deflection of the reflecting mirror on the scanning motor, two off-axis The switching of the optical path of the on-axis reflector telescope realizes the detection of two off-axis reflector telescopes. The light emitted from the laser light source is reflected by the mirror on the scanning motor and enters the compensation mirror 3 of the off-axis reflection telescope, then refracted to the secondary mirror 2 of the telescope through the compensation mirror 3, and then reflected to the main off-axis reflection telescope through the inclined secondary mirror 2 Mirror 1 is emitted into the atmosphere by the main mirror 1 of the off-axis reflecting telescope; as a carrier signal, the laser beam interacts with molecules and aerosol particles in the atmosphere to generate an echo signal, and the echo signal returned from the atmosphere is sent by the same off-axis reflecting telescope After receiving, the main mirror 1, the secondary mirror 2, the compensation mirror 3 of the off-axis reflecting telescope, and the mirror on the scanning motor are reflected to the subsequent optical path.

The two off-axis reflective telescopes W ₁ and W ₂ work in an alternate mode, and after one off-axis reflective telescope completes m laser pulse detections, it switches to the other off-axis reflective telescope; m=50.

The main functions of the telescope scanning optical system 5 are: ① when the system is working normally, to emit laser light and receive echo; ② to provide back-reflected light when performing precision correction on lag angle compensation. the

The structure of the lag angle compensation module 6 is as shown in Figure 2, which includes: a rotation compensator 601, a translation compensator 606, a rotation light guide mirror 603, a translation light guide mirror 604, a first connector 602 and a second connector 605 The rotating light guide mirror 603 is fixedly connected with the rotation compensator 601 through the first connector 602; the translation light guide mirror 604 is fixedly connected with the translation compensator 606 through the second connector 605; in the initial state, the rotation light guide mirror 603 and the translation The zero position of the light guide mirror 604 is placed in parallel and forms an angle of 45° with the horizontal direction;

Among them, the rotation compensator 601 and the translation compensator 606 are selected from high-precision and high-resolution piezoelectric swing platform Puai Nano Displacement Technology Co., Ltd., and the product model is S-330.2SL. the

The functions of the lag angle compensation module 6 include: ① When the spaceborne lidar wind measurement system is working normally, perform lag angle compensation. ② When the spaceborne lidar wind measurement system is in the lag angle compensation accuracy correction stage, the lag angle compensation accuracy correction work is performed. the

The function of the movable plug-in reflector 7 is: when the spaceborne wind-measuring laser radar system needs to correct the lag angle compensation accuracy, the movable plug-in reflector 7 is moved into the optical path, and the movable plug-in reflector 7 will be The back-reflected light beam from the compensating mirror 3 in the off-axis reflecting telescope W ₁ is transmitted to the beam expander 8 .

The function of the beam expander 8 is to reduce the back-reflected light signal beam diameter of the compensating mirror 3 in the off-axis reflecting telescope W ₁ by Multiplied down to fit the size of the area array detector.

The area array photodetector 9 is an area array photodetector with an imaging area size of 320×256, a pixel size of 30 μm×30 μm, and an image plane size of 9.6 mm×7.68 mm. Its function is to receive the light spot in the beam expander 8 and transmit it to the control signal processing module 10 after imaging. the

The functions of the control signal processing module 10 include: 1. When the spaceborne wind-measuring lidar system works normally, the control signal processing module 10 sends an upper lag angle compensation signal or a lower lag angle compensation signal to the lag angle compensation module 6; Send movable insertable reflector 7 to move out signal to movable insertable reflector 7; Send closing signal to area array photodetector ₉ ; When the off-axis reflecting telescope W ₂ works normally, the control signal processing module 10 sends a move-in signal to the scan controller 4 . ② When the spaceborne wind-measuring lidar system is in the lag angle compensation accuracy correction stage, the control signal processing module 10 sends an accuracy correction signal to the lag angle compensation module 6; sends the movable plug-in mirror 7 to the movable plug-in mirror 7. Move in signal; send open signal to area array photodetector 9; send out signal to scan controller 4.

The connection relationship of the above parts is as follows:

The lag angle compensation module 6 is located behind the dual-telescope scanning optical system 5; when the system is working normally, the echo laser is transmitted to the lag angle compensation module 6 through the dual-telescope scanning optical system 5, and then transmitted to the peripheral equipment after being compensated by the lag angle compensation module 6 ; When performing lag angle compensation accuracy correction, the movable plug-in mirror 7 is located on the optical path behind the lag angle compensation module 6, and the beam expander 8 is placed on one side of the movable plug-in mirror 7 and is located in the area array photoelectric detection The front end of the device 9; the output terminal of the area array photodetector 9 is connected to the input terminal of the control signal processing module 10; the output terminal of the control signal processing module 10 is connected to the input terminal of the lag angle compensation module 6. the

Use the lag angle compensation device of the spaceborne wind measurement laser radar system described in this embodiment to compensate the lag angle, and the specific operation steps are:

Step 1: Make the spaceborne wind-measuring lidar system in the normal working stage, control the signal processing module 10 to send the movable plug-in reflector 7 to move out signal, and the movable plug-in reflector 7 moves out System optical path; control signal processing module 10 sends closing signal to area array photodetector ₉ , and area array photodetector ₉ is closed; When the off-axis reflecting telescope W ₁ is working normally, the control signal processing module 10 sends a signal to move out of _the scanning controller 4, and the scanning controller 4 moves out of the system optical path; To move in the signal, the scan controller 4 moves into the optical path of the system.

Step 2: The control signal processing module 10 sends an upper lag angle compensation signal or a lower lag angle compensation signal to the lag angle compensation module 6 . the

When the off-axis reflecting telescope _W1 in the telescope scanning optical system 5 is working normally, the control signal processing module 10 sends an upper lag angle compensation signal.

When the off-axis reflecting telescope _W2 in the telescope scanning optical system 5 is working normally, the control signal processing module 10 sends a downward lag angle compensation signal.

Step 3: The lag angle compensation module 6 completes the lag angle compensation work according to the upper lag angle compensation signal or the lower lag angle compensation signal sent from the control signal processing module 10 . Specifically:

Step 3.1: When the lag angle compensation module 6 receives the upper lag angle compensation signal, the specific operation is: the rotating compensator 601 controls the rotating light guide mirror 603 to rotate to the zero position, and then rotates clockwise to the angle of θ/2 degrees from the initial position position, where θ is the lag angle, θ=0.360/π degrees; the translation compensator 606 controls the translation light guide mirror 604 to rotate to the zero position, and then translates H×tanθ to the right, where H is the focus of the off-axis reflecting telescope W ₁ The distance to the center of symmetry of the rotating light guide mirror 603 is H=1.5m. After the rotation compensator 601 and the translation compensator 606 complete the control, the operation ends.

Step 3.2: When the lag angle compensation module 6 receives the lower lag angle compensation signal, the specific operation is: the rotation compensator 601 controls the rotation of the light guide mirror 603 to the zero position, and then rotates counterclockwise to the angle of θ/2 degrees from the initial position position; the translation compensator 606 controls the translation light guide mirror 604 to rotate to the zero position, and then translates H×tanθ to the left. After the rotation compensator 601, the translation compensator 606 and the scan controller 4 complete the control, the operation ends. the

The working process of using the lag angle compensation device of the spaceborne wind measurement lidar system to correct the lag angle accuracy is as follows:

Step a: Make the spaceborne wind-measuring lidar system in the lag angle accuracy correction stage, control the signal processing module 10 to send the movable plug-in reflector 7 to move in signal to the movable plug-in reflector 7, and move the plug-in reflector 7 7 moves into the optical path of the system; the control signal processing module 10 sends an open signal to the area array photodetector 9, and the area array photodetector 9 works normally; the control signal processing module 10 sends a signal for the scanning controller 4 to move out, and the scanning controller 4 moves out of the system optical path , the control signal processing module 10 issues a reset command to the lag angle compensation module 6, and the rotating light guide mirror 603 and the translation light guide mirror 604 are reset to the zero position;

Step b: Control the signal processing module 10 to read the back-reflected light spot image of the compensating mirror 3 in the off-axis reflecting telescope W ₁ obtained by the area array photodetector 9, and calculate the center of the light spot obtained by the area array photodetector 9 and The difference ΔL of the abscissa of the central point of the area array photodetector 9; the signal processing module 10 further calculates the fine-tuning rotation amount α/2 of the rotation compensator 601, and compares the light spot center obtained by the area array photodetector 9 with the area array The difference ΔL of the abscissa of the central point of the photodetector 9 and the fine-tuning rotation amount α/2 are sent to the lag angle compensation module 6 . The value of α can be calculated by formula 1, where h=0.5m,

Step c: the lag angle compensation module 6 completes the lag angle accuracy correction work; the specific operation is: whether the detection rotating light guide mirror 603 is in the zero position, if the spot center obtained by the area array photodetector 9 is the same as the center of the area array photodetector 9 If the difference ΔL of the abscissa of the point satisfies |ΔL|<σ, σ=1.5 microns, then the rotating light guide mirror 603 is considered to be at the zero point position, and compensation correction is not required; otherwise, when ΔL is a positive value, the rotating compensator 601 controls the rotating light guide mirror 603 to rotate α/2 degrees counterclockwise from the current position; when ΔL is a negative value, the rotation compensator 601 controls the rotating light guide mirror 603 to rotate clockwise α/2 degrees from the current position. Repeat step c until the detected |ΔL|<σ, stop the operation. the

The main content of the present invention has been introduced in detail through the above preferred examples, and it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the above disclosure. Therefore, the protection scope of the present invention should be defined by the appended claims. the

Claims (3)

1. a satellite-bone laser radar wind measuring system drag angle compensation system, is characterized in that: it comprises: telescope scanning optics (5), drag angle compensating module (6), removable plug-in type catoptron (7), beam expanding lens (8), face battle array photodetector (9) and control signal processing module (10); The systematic optical axis of described satellite-bone laser radar wind measuring system drag angle compensation system is represented with symbol a;

Described telescope scanning optics (5) comprises scanning monitor (4) the off axis reflector telescope W identical with two ₁and W ₂; Off axis reflector telescope W ₁optical axis parallel with the systematic optical axis a of described satellite-bone laser radar wind measuring system drag angle compensation system; Off axis reflector telescope W ₁and W ₂equal with the distance of scanning monitor (4) respectively, and off axis reflector telescope W ₁and W ₂form an angle with the line of scanning monitor (4); Each off axis reflector telescope is made up of primary mirror (1), secondary mirror (2) and compensating glass (3); Scanning monitor (4) is made up of a scan module and a plane mirror; By the deflection of the catoptron on scan module, carry out the switching of 2 off axis reflector telescope light paths, realize 2 telescopical detections of off axis reflector; The telescopical compensating glass of off axis reflector (3) is entered via the catoptron reflection scan module from the light of LASER Light Source outgoing, then telescope secondary mirror (2) is refracted to through compensating glass (3), reflex to off axis reflector telescope primary mirror (1) via the secondary mirror (2) tilted again, be transmitted in air by off axis reflector telescope primary mirror (1); Laser is as carrier signal, interact with the molecule in air and particulate and produce echoed signal, the echoed signal returned from air is received by same off axis reflector telescope, via the telescopical primary mirror of off axis reflector (1), secondary mirror (2), compensating glass (3) to the catoptron on scan module, reflex in subsequent optical path;

Two off axis reflector telescope W ₁and W ₂for alternation pattern, after an off axis reflector telescope completes m laser pulse detection, switch to another off axis reflector telescope wherein; M value by people for presetting, m ∈ [20,100];

The Main Function of described telescope scanning optics (5) is: 1. when system worked well, Emission Lasers and reception echo; 2., when carrying out adjustment in accuracy to drag angle compensation, back reflected laser is provided;

Described drag angle compensating module (6) comprising: whirl compensator (601), translation compensation device (606), rotate guide-lighting mirror (603), the guide-lighting mirror (604) of translation, the first web member (602) and the second web member (605); Rotate guide-lighting mirror (603) to be fixedly connected with whirl compensator (601) by the first web member (602); The guide-lighting mirror (604) of translation is fixedly connected with translation compensation device (606) by the second web member (605); In original state, rotate the null position of the guide-lighting mirror (604) of guide-lighting mirror (603) and translation for both parallel placements and from the horizontal by 45 ° of angles;

The function of described drag angle compensating module (6) comprising: 1. when described satellite-bone laser radar wind measuring system normally works, carry out drag angle compensation work; 2., when described satellite-bone laser radar wind measuring system is in the drag angle compensation precision correction stage, drag angle compensation precision correction work is carried out;

The function of described removable plug-in type catoptron (7) is: when described spaceborne anemometry laser radar system needs to carry out the correction of drag angle compensation precision, removable plug-in type catoptron (7) is moved in light path, and removable plug-in type catoptron (7) is by off axis reflector telescope W ₁the back reflected laser beam Propagation of middle compensating glass (3) is to beam expanding lens (8);

The function of described beam expanding lens (8) is by off axis reflector telescope W ₁the retroreflection optical signal beam diameter of middle compensating glass (3) reduces by multiple, with the size of adaptive surface array detector; Described multiple is optional

The function of described battle array photodetector (9) receives the hot spot in beam expanding lens (8), transfers to control signal processing module (10) after imaging;

The function of described control signal processing module (10) comprising: 1. when described spaceborne anemometry laser radar system worked well, and control signal processing module (10) sends top drag angle compensating signal or below drag angle compensating signal to drag angle compensating module (6); Send removable plug-in type catoptron (7) to removable plug-in type catoptron (7) and shift out signal; Shutdown signal is sent to face battle array photodetector (9); And at off axis reflector telescope W ₁during normal work, control signal processing module (10) sends to scanning monitor (4) and shifts out signal; At off axis reflector telescope W ₂during normal work, control signal processing module (10) sends immigration signal to scanning monitor (4); 2. when described spaceborne anemometry laser radar system is in the drag angle compensation precision correction stage, control signal processing module (10) sends adjustment in accuracy signal to drag angle compensating module (6); Send removable plug-in type catoptron (7) to removable plug-in type catoptron (7) and move into signal; Opening signal is sent to face battle array photodetector (9); Send to scanning monitor (4) and shift out signal;

The annexation of each part mentioned above is:

After drag angle compensating module (6) is positioned at two telescope scanning optics (5); When system worked well, echo laser transfers to drag angle compensating module (6) through two telescope scanning optics (5), after drag angle compensating module (6) compensates, transfer to peripherals; When carrying out the correction of drag angle compensation precision, removable plug-in type catoptron (7) is positioned in the light path after drag angle compensating module (6), and beam expanding lens (8) is positioned over the side of removable plug-in type catoptron (7) and is positioned at the front end in face battle array photodetector (9); The input end of the output termination control signal processing module (10) in face battle array photodetector (9); The input end of output termination drag angle compensating module (6) of control signal processing module (10).

2. spaceborne anemometry laser radar system drag angle compensation system as claimed in claim 1, is characterized in that: use it to the course of work that drag angle compensates to be:

Step 1: make described spaceborne anemometry laser radar system be in normal work stage, control signal processing module (10) sends removable plug-in type catoptron (7) to removable plug-in type catoptron (7) and shifts out signal, and removable plug-in type catoptron (7) shifts out system light path; Control signal processing module (10) sends shutdown signal to face battle array photodetector (9), and face battle array photodetector (9) is closed; Control signal processing module (10) is according to off axis reflector telescope W ₁and W ₂between work schedule, at off axis reflector telescope W ₁during normal work, control signal processing module (10) sends scanning monitor (4) and shifts out signal, and scanning monitor (4) shifts out system light path; At off axis reflector telescope W ₂during work, control signal processing module (10) sends scanning monitor (4) and moves into signal, and scanning monitor (4) moves into system light path;

Step 2: control signal processing module (10) sends top drag angle compensating signal or below drag angle compensating signal to drag angle compensating module (6);

As off axis reflector telescope W in telescope scanning optics (5) ₁during normal work, control signal processing module (10) sends top drag angle compensating signal;

As off axis reflector telescope W in telescope scanning optics (5) ₂during normal work, control signal processing module (10) sends below drag angle compensating signal;

Step 3: the top drag angle compensating signal that drag angle compensating module (6) sends according to control signal processing module (10) or below drag angle compensating signal, complete drag angle compensation work; Be specially:

Step 3.1: when drag angle compensating module (6) receives top drag angle compensating signal, concrete operations are: whirl compensator (601) controls to rotate guide-lighting mirror (603) and turns to null position, dextrorotation goes to and is set to degree position, θ/2 with initial bit again, wherein θ is drag angle, θ by people for presetting, θ ∈ [9 × 10 ^-4/ π, 0.36/ π] degree; Translation compensation device (606) controls the guide-lighting mirror (604) of translation and turns to null position, then to right translation H × tan θ, wherein H is off axis reflector telescope W ₁focus to the distance rotating guide-lighting mirror (603) symcenter point; After whirl compensator (601) and translation compensator (606) complete control, end operation;

Step 3.2: when drag angle compensating module (6) receives below drag angle compensating signal, concrete operations are: whirl compensator (601) controls to rotate guide-lighting mirror (603) and turns to null position, then is rotated counterclockwise and is set to degree position, θ/2 to initial bit; Translation compensation device (606) controls the guide-lighting mirror (604) of translation and turns to null position, then to left H × tan θ; After whirl compensator (601), translation compensation device (606) and scanning monitor (4) complete control, end operation.

3. spaceborne anemometry laser radar system drag angle compensation system as claimed in claim 1 or 2, is characterized in that: use it to the course of work of drag angle adjustment in accuracy to be:

Step a: make described spaceborne anemometry laser radar system be in the drag angle adjustment in accuracy stage, control signal processing module (10) sends removable plug-in type catoptron (7) to removable plug-in type catoptron (7) and moves into signal, and removable plug-in type catoptron (7) moves into system light path; Control signal processing module (10) sends opening signal to face battle array photodetector (9), and face battle array photodetector (9) normally works; Control signal processing module (10) sends scanning monitor (4) and shifts out signal, scanning monitor (4) shifts out system light path, control signal processing module (10) sends reset command to drag angle compensating module (6), rotates the guide-lighting mirror (604) of guide-lighting mirror (603) and translation and is reset to null position;

Step b: the off axis reflector telescope W that control signal processing module (10) reading face battle array photodetector (9) obtains ₁the back reflected laser light spot image of middle compensating glass (3), and the difference Δ L calculating the horizontal ordinate of the central point in spot center that face battle array photodetector (9) obtains and face battle array photodetector (9); Signal processing module (10) calculates fine setting rotation amount α/2 of whirl compensator (601) further, and the difference Δ L of the horizontal ordinate of the central point in the spot center that face battle array photodetector (9) is obtained and face battle array photodetector (9) and finely tune rotation amount α/2 and send to drag angle compensating module (6); The value of α calculates by formula (1);

ΔL·AF＝h·tanα (1)

Wherein, h rotates guide-lighting mirror (603) the symcenter point distance to face battle array photodetector (9), AF be beam expanding lens (8) expand multiple;

Step c: drag angle compensating module (6) completes the work of drag angle adjustment in accuracy; Concrete operations are: detect the guide-lighting mirror of rotation (603) and whether be in null position, if the difference Δ L of the horizontal ordinate of the central point in the spot center that face battle array photodetector (9) obtains and face battle array photodetector (9), if | Δ L| < σ sets up, σ is for presetting threshold value, σ ∈ [0,10] micron, then think that rotating guide-lighting mirror (603) is in null position, does not need to do compensating approach; Otherwise, when Δ L be on the occasion of time, whirl compensator (601) control rotate guide-lighting mirror (603) be rotated counterclockwise α/2 degree from current location; When Δ L is negative value, whirl compensator (601) controls to rotate guide-lighting mirror (603) and to turn clockwise α/2 degree from current location; Repeat step c, until detect | Δ L| < σ, shut-down operation.