CN116880055A - Alignment adjustment method between the adaptive optical terminal and the main optical system on the telescope machine - Google Patents

Abstract

The invention relates to a method for adjusting the alignment of a self-adaptive optical terminal and a main optical system on a telescope machine, which comprises the following steps: installing a laser calibration light source at the center of the secondary mirror, installing a self-adaptive optical terminal, and enabling the laser calibration light source to irradiate a Hartmann camera target surface by adjusting a Pick-up assembly; and (3) timely placing the small-caliber collimator at the center of the secondary mirror, and repeatedly using a telescope to image natural star observation or image the small-caliber collimator until the natural star imaging is positioned at the center of the sub-aperture of the Hartmann camera. The method for adjusting the alignment of the self-adaptive optical terminal and the main optical system on the telescope machine can rapidly and safely finish the butt joint work of the self-adaptive optical system and the main system on the telescope machine by adopting the method of combining the laser through shaft and the relative offset error compensation.

Description

Alignment adjustment method between the adaptive optical terminal and the main optical system on the telescope machine

Technical field

The invention relates to the technical field of telescope imaging quality, and in particular to a method for aligning and adjusting an adaptive optical terminal on a telescope machine and a main optical system.

Background technique

In order to overcome the impact of atmospheric turbulence on the imaging quality of telescopes, adaptive optics technology based on deformable mirrors was invented. The core mainly includes Hartmann imaging components and deformable mirrors. The Hartmann imaging components and deformable mirrors are located behind the primary mirror. Pupil position, in which the deformable mirror is the exit pupil of the main mirror, and the Hartmann imaging component is the exit pupil of the deformable mirror. The three achieve pupil matching. During observation, the Hartmann imaging component calculates the centroid position of the target on each sub-aperture and calculates the overall tilt. At the same time, it uses the wavefront processor to calculate the instantaneous wavefront information through fitting, and controls and drives the deformable mirror to correct the wave in real time. Front distortion to overcome high-order wavefront aberration caused by atmospheric turbulence. As the core component of the adaptive optical system, the Hartmann imaging component has the characteristics of small field of view, high precision and small dynamic range. Therefore, how to quickly, safely and accurately realize the alignment of the adaptive optical terminal and the main optical system has always been a problem. is a difficult problem.

Existing adaptive optics systems are mainly divided into off-machine systems and on-board systems based on their placement. There are many methods for aligning and adjusting the adaptive optics terminal and telescope. For off-machine systems, the adaptive optics system is located in the warehouse. It does not move with the rotation of the telescope, and can adjust the star in real time, which is very convenient; however, for the on-board system, the adaptive system rotates in real time with the telescope. When the star is adjusted, the telescope is always powered on, and there is a risk of overspeeding when scientific researchers adjust the telescope. , has a certain degree of danger. At the same time, because the telescope has a certain pitch angle, it is not conducive to operation when adjusting the stars.

Contents of the invention

The present invention aims to solve the technical problems in the prior art and provide a method for aligning and adjusting an adaptive optical terminal on a telescope machine and a main optical system.

In order to solve the above technical problems, the technical solutions of the present invention are as follows:

A method for aligning and adjusting the adaptive optical terminal on the telescope machine and the main optical system. Systems applicable to the alignment adjustment method include:

a telescope provided with a secondary mirror;

Laser calibration light source, which is used to emit laser as the calibration light source;

Small-diameter collimated light tube, which is used as an imaging light source;

Adaptive optics terminal, which is equipped with Hartmann camera and Pick-up components;

The alignment adjustment method includes the following steps:

Step i: Install a laser calibration light source at the center of the secondary mirror, install an adaptive optical terminal, and adjust the Pick-up component to illuminate the laser calibration light source onto the Hartmann camera target surface;

Step ii: Place the small-diameter parallel light tube at the center of the secondary mirror in a timely manner, and repeatedly use the telescope to observe and image natural stars or image the small-diameter parallel light tube until the natural star imaging is located on the Hartmann camera. Aperture center.

In the above technical solution, step i specifically includes the following steps:

Install a laser calibration light source at the center of the secondary mirror, and adjust the attitude of the laser calibration light source so that its laser emission direction coincides with the primary optical axis;

According to the position of the light spot, adjust the Pick-up component inside the adaptive optics terminal until the light spot appears near the center of the Hartmann camera target surface and is imaged.

In the above technical solution, step ii specifically includes the following steps:

The first step: replace the laser calibration light source with a small-diameter parallel light tube and image it on the Hartmann camera;

Step 2: Use the telescope to image natural stars, adjust the pointing of the telescope, record the imaging position of natural stars in the Hartmann camera, and calculate its offset Δ and tilt θ;

The third step: open the small-diameter parallel light tube, use the Hartmann camera to image the small-diameter parallel light tube, and record the imaging position of the small-diameter parallel light tube;

Step 4: Adjust the imaging position of the small-aperture parallel light tube through the Pick-up component. The adjustment amounts are offset-Δ and tilt-θ. After the adjustment is completed, use the telescope to observe natural stars again; use the telescope repeatedly to observe natural stars. Observe the imaging and image the small-aperture collimator so that the offset Δ and the tilt θ approach 0.

In the above technical solution, the pick-up component includes: two reflectors with an included angle of 90°, which can achieve 90° refraction of the optical path.

The invention has the following beneficial effects:

The alignment adjustment method between the telescope on-board adaptive optical terminal and the main optical system of the present invention adopts a method that combines laser axis penetration and relative misalignment error compensation, and can quickly and safely complete the docking work between the on-board adaptive optical system and the main system.

Description of the drawings

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Figure 1 is a schematic diagram of the telescope system.

Figure 2 is a schematic diagram of the Pick-up component.

Figure 3 is an overall flow chart of the alignment adjustment method between the adaptive optical terminal and the main optical system on the telescope machine according to the present invention.

Figure 4 is a schematic diagram of the alignment and fine adjustment of the onboard adaptive optical terminal and the telescope’s main optical system.

The reference numbers in the figure are:

1-Secondary mirror; 2-Laser calibration light source; 3-Adaptive optical terminal; 4-Pick-up component; 5-Hartmann camera; 6-Small aperture collimated light tube.

Detailed ways

The inventive idea of the present invention is: the present invention adopts the method of combining laser axis penetration and relative misalignment error compensation, which can quickly and safely complete the docking work of the on-board adaptive optical system and the main system.

The specific workflow is as follows:

First, a laser calibration light source is installed at the center of the secondary mirror, with the laser beam representing the actual optical axis of the telescope. Then the adaptive optics terminal is installed, and the pick-up component inside the platform is adjusted so that the laser calibration light source illuminates the target surface of the Hartmann camera. To achieve rough alignment of adaptive optics terminals and telescopes;

Secondly, the laser calibration light source is replaced with a small-diameter parallel light tube. The light emitted by the small-diameter parallel light tube can be imaged on the target surface of the Hartmann camera and the imaging position is recorded;

Finally, use the telescope to observe and image natural stars. You can see the imaging position of natural stars in the sub-aperture of the Hartmann camera. Calculate the offset Δ and tilt θ between the actual imaging position and the theoretical imaging position, and image the small-aperture light pipe again. Adjust the Pick-up component inside the adaptive optics terminal so that its imaging position moves offset -Δ and tilt -θ, and then observe the natural star again. Repeat this several times until the natural star image is located at the center of the Hartmann camera sub-aperture, then The adaptive optical terminal is aligned with the main optical system.

The present invention will be described in detail below with reference to the accompanying drawings.

The basic contents of the present invention are detailed as follows:

Figure 1 shows the entire telescope system diagram, which mainly consists of a tracking frame, a four-way, a primary mirror, a secondary mirror 1, a third mirror, a secondary mirror tube, a secondary mirror ring beam, and an adaptive optical terminal 3. During observation, the light is reflected along the primary mirror, secondary mirror 1 and third mirror respectively to the adaptive optical terminal 3 of the telescope Ness platform. The adaptive optical terminal 3 contains multiple imaging cameras, such as the Hartmann camera with a small field of view and high precision. Camera 5, but due to installation errors, Hartmann Camera 5 cannot image the target without adjustment.

The present invention mainly solves the problem of docking between the adaptive optical terminal 3 and the main optical system. The method for aligning and adjusting the adaptive optical terminal on the telescope machine and the main optical system of the present invention includes the following steps:

First, install the laser calibration light source 2 in the center of the secondary mirror 1 to represent the optical axis of the telescope, as shown in Figure 1. The difference from the actual imaging process is that the laser calibration light source 2 does not pass through the primary mirror and secondary mirror 1, but directly passes through the third mirror. The reflection enters the adaptive optics terminal 3, and then the Pick-up component 4 inside the adaptive optics terminal 3 is adjusted until the Hartmann camera 5 images the laser calibration light source 2.

Secondly, the laser calibration light source 2 is replaced with a small-diameter collimated light tube 6. The light emitted by the small-diameter collimated light tube 6 is imaged on the target surface of the Hartmann camera 5, and the imaging position is recorded; then, Polaris is selected as the natural star for observation, and the The telescope observes natural stars, records the imaging position of the natural stars in the Hartmann camera 5, and calculates its offset Δ and tilt θ; the small-aperture collimator 6 replaces the laser calibration light source 2 and images the small-aperture collimator 6 again , adjust the imaging position of the small-aperture collimator 6 through the Pick-up component 4 by -Δ and -θ, and repeat this several times to align the adaptive optics terminal 3 with the telescope.

The Pick-up component 4 is composed of two reflectors with an included angle of 90°, which can achieve 90° refraction of the optical path. The specific structure is shown in Figure 2, and mainly includes: the first Pick-up mirror; Adjust the top screw, the second Pick-up mirror, and the second Pick-up mirror. Adjust the top screw and lens barrel. Each mirror can adjust the x and y two-dimensional tilt. By swapping and cooperating with each other, the optical path pupil matching can be achieved. .

The overall implementation process of the alignment adjustment method between the adaptive optical terminal and the main optical system on the telescope according to the present invention is shown in Figure 3. It can be seen from the overall flow chart that the connection between the adaptive optical terminal and the main optical system is divided into two parts: rough alignment and fine adjustment.

In the rough alignment stage, the laser calibration light source 2 is installed at the center of the secondary mirror 1, and the attitude of the laser calibration light source 2 is adjusted so that its laser emission direction coincides with the primary optical axis. This is different from the actual observation and imaging of the telescope. The laser calibration light source 2 emits The light is not reflected by the primary mirror and the secondary mirror 1, but is directly reflected by the three mirrors to the inside of the adaptive optical terminal 3. The adaptive optics terminal 3 and the telescope four-way are fixed with screws, and the positioning accuracy is poor. At this time, the Hartmann camera 5 cannot image the laser calibration light source 2. According to the spot position, the approximation method is used to continuously adjust the Pick-up located inside the platform. Component 4 is tilted until the light spot appears near the center of the target surface of Hartmann camera 5 and is imaged. At this point, the adjustment of the rough alignment stage is completed.

The fine adjustment stage is divided into the following four steps:

The first step: replace the laser calibration light source 2 with a small-aperture collimator 6 and image it on the Hartmann camera 5;

Step 2: Use the telescope to image Polaris, adjust the telescope pointing, record the imaging position of Polaris in Hartmann Camera 5, and calculate its offset Δ and tilt θ, as shown in Figure 4;

Step 3: Open the small-diameter collimator 6, use the Hartmann camera 5 to image the small-diameter collimator 6, and record the imaging position of the small-diameter collimator 6;

Step 4: Adjust the imaging position of the small-aperture collimator 6 through the Pick-up component 4 located inside the platform. The adjustment amounts are offset-Δ and tilt-θ. After the adjustment is completed, use the telescope to observe Polaris again and use the approximation method. Repeat this several times until the offset Δ and tilt θ approach 0. At this point, the precise adjustment is completed and the docking of the adaptive optics terminal 3 and the telescope is completed.

In the specific embodiment of the present invention, a small-diameter parallel light pipe has the same meaning as a small-diameter light pipe and a light pipe, and both refer to a small-diameter parallel light pipe. The natural star used for imaging is selected as Polaris. In other specific embodiments, other natural stars suitable for observation can also be selected for observation and imaging using a telescope.

The alignment adjustment method between the telescope on-board adaptive optical terminal and the main optical system of the present invention adopts a method that combines laser axis penetration and relative misalignment error compensation, and can quickly and safely complete the docking work between the on-board adaptive optical system and the main system.

Obviously, the above-mentioned embodiments are only examples for clear explanation and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. An exhaustive list of all implementations is neither necessary nor possible. The obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims (4)

1. An alignment adjustment method for a self-adaptive optical terminal and a main optical system on a telescope machine is characterized in that the system suitable for the alignment adjustment method comprises the following steps:

a telescope provided with a secondary mirror (1);

a laser calibration light source (2), wherein the laser calibration light source (2) is used for emitting laser as a calibration light source;

a small-caliber collimator (6), the small-caliber collimator (6) being used as an imaging light source;

an adaptive optical terminal (3), wherein a Hartmann camera (5) and a Pick-up assembly (4) are arranged in the adaptive optical terminal (3);

the alignment adjustment method comprises the following steps:

step i: a laser calibration light source (2) is arranged at the center of the secondary mirror (1), a self-adaptive optical terminal (3) is arranged, and the laser calibration light source (2) irradiates to the target surface of the Hartmann camera (5) by adjusting the Pick-up assembly (4);

step ii: and (3) timely placing the small-caliber collimator (6) at the central position of the secondary mirror (1), and repeatedly utilizing a telescope to image natural star observation or image the small-caliber collimator (6) until the natural star imaging is positioned at the center of the sub-aperture of the Hartmann camera (5).

2. The method for adjusting the alignment of an adaptive optics terminal and a main optical system on a telescope as recited in claim 1, wherein the step i comprises the steps of:

a laser calibration light source (2) is arranged at the center of the secondary mirror (1), and the posture of the laser calibration light source (2) is adjusted to enable the laser emergent direction to coincide with the main optical axis;

and adjusting a Pick-up component (4) in the adaptive optical terminal (3) according to the light spot position until the light spot appears near the center position of the target surface of the Hartmann camera (5) and is imaged.

3. The method for aligning an adaptive optics terminal with a main optical system on a telescope as recited in claim 1, wherein step ii comprises the steps of:

the first step: replacing the laser calibration light source (2) with a small-caliber collimator (6), and imaging in a Hartmann camera (5);

and a second step of: using a telescope to image the natural star, adjusting the pointing direction of the telescope, recording the imaging position of the natural star in the Hartmann camera (5), and calculating the offset delta and the inclination theta of the natural star;

and a third step of: opening the small-caliber collimator (6), imaging the small-caliber collimator (6) by using the Hartmann camera (5), and recording the imaging position of the small-caliber collimator (6);

fourth step: the imaging position of the small-caliber collimator (6) is adjusted through the Pick-up assembly (4), the adjustment quantity is offset-delta and inclination-theta, and after the adjustment is finished, a telescope is used for observing natural stars again; the telescope is repeatedly used for observing and imaging the natural star and imaging the small-caliber collimator (6) so that the offset delta and the inclination theta are approximate to 0.

4. A method of alignment adjustment of an adaptive optics terminal and a main optical system on a telescopic machine according to any one of claims 1-3, wherein the Pick-up assembly (4) comprises: the two reflectors with the included angle of 90 degrees can realize the 90-degree deflection of the light path.