Disclosure of Invention
To overcome the problem that there is no system or method for automatically measuring the atmospheric coherence length 24 in the prior art, the present invention provides a method using an all-weather atmospheric coherence length measuring system.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for using all-weather atmosphere coherence length measuring system, the system includes atmosphere coherence length appearance, base used for supporting the atmosphere coherence length appearance, make the atmosphere coherence length appearance rotate with respect to base level and pitching the rotatory drive assembly, control module; the atmospheric coherence length instrument comprises a shell, a telescope, a camera and a GPS measuring component, wherein the telescope, the camera and the GPS measuring component are arranged in the shell; the control module is correspondingly connected with the controlled end of the driving assembly, the controlled end of the focusing mechanism, the data acquisition end of the atmospheric coherence length instrument and the data input end. The method comprises the following steps:
s1, powering on the system, and driving the atmospheric coherence length instrument to be at an initial position by the driving assembly; the control module configures the camera exposure parameters into the camera from the data input end of the atmospheric coherence length instrument; the control module acquires system information from a data acquisition end;
s2, the control module calls the internally stored star map information, selects the star with the highest brightness in the set range of the pitch angle of the atmospheric coherence length instrument on the star map information according to the system information, and determines the position of the star; the control module calculates the angle information of the atmospheric coherence length instrument to enable the imaging position to be located at the center of the camera;
s3, the stars obtain two light spots in the camera, whether the distance between the two mass center positions exceeds a set value or not is judged, and when the distance exceeds the set value, the control module controls the focusing mechanism to focus;
s4, the control module determines the running track of the stars according to the star map information, the atmospheric coherence length instrument moves according to the motion track by controlling the driving assembly, the control module obtains the centroid position of the image calculated by the camera in the process of moving according to the motion track, and then the control module calculates the corresponding coherence length;
s5, the control module stores the coherence length and the corresponding system information, angle information and star type;
s6, the control module determines the running track of the stars according to the star map information and enables the atmospheric coherence length instrument to move according to the running track by controlling the driving assembly;
s7, when the atmospheric coherence length instrument angle is smaller than the set range in the step S2, the control module reselects the star with the highest brightness in the set range of the atmospheric coherence length instrument angle on the star map information according to the current system information, and determines the star position; the control module calculates the atmospheric coherence length instrument angle, and the light of the selected star in this step is imaged at the center of the camera, and returns to step S4.
Preferably, the driving assembly comprises a U-shaped support, the two sides of the horizontal direction of the shell are respectively and correspondingly and rotatably connected with the inner sides of the two vertical parts of the U-shaped support, and a control circuit serving as a control module is further arranged inside the vertical part of the U-shaped support.
Preferably, the camera is a high-speed intelligent camera.
Specifically, the control module calculates the horizontal rotation angle and the pitch angle of the atmospheric coherence length instrument in step S2 to make the imaging position be located at the center of the camera, and specifically includes the following steps:
s21, the control module controls the driving component by calculating the horizontal rotation angle and the pitching angle of the atmospheric coherence length instrument to enable the telescope of the atmospheric coherence length instrument to initially aim at the star;
and S22, imaging the light of the stars incident into the telescope through the system, and controlling the driving assembly by the control module to enable the telescope of the atmospheric coherence length instrument to accurately aim at the stars until the imaging position is located at the center of the camera according to the position of the imaged light spot in the camera.
Specifically, the pitch angle in step S2 is set to be not less than 30 degrees.
Specifically, the set value of the distance between the two centroids in step S3 is 300 pixels, and the allowable error is 20 pixels.
Specifically, the centroid positions of the two light spots in step S3 are calculated by the camera itself, and the centroid calculation formula is
Wherein, x and y are coordinate values, I (x), and I (y) are light intensity in x and y directions.
Specifically, the angle information includes a horizontal rotation angle and a pitch angle, and the initial position in step S1 is such that both the horizontal rotation angle and the pitch angle are 0 degrees.
Specifically, the system information includes GPS information of the location and corresponding time information.
The invention has the advantages that:
(1) the invention realizes 24-hour all-weather atmospheric coherence length measurement by measuring stars, does not need a light source by utilizing the brightness of the starlight, realizes automatic control by the control module, does not need leveling and is simple to use.
(2) According to the invention, the regulation of the pitch angle is realized by controlling the rotation of the atmospheric coherence length instrument on the U-shaped bracket, and the horizontal rotation angle regulation is realized by horizontally rotating the U-shaped bracket on the base.
(3) The invention realizes that the telescope receives the light of a star to be aimed and then images in the camera through rough adjustment when the angle of the telescope is adjusted, and then the imaging position is positioned at the center of the camera through fine adjustment.
(4) And determining the defocusing amount of the rubber surface according to the difference value between the distance of the two light spots calculated by the imaging theory and the actually measured light spot distance.
(5) The setting range of the pitch angle in step S2 is not less than 30 degrees, and the larger the pitch angle, the longer the trackable time of the system for each star.
(6) The distance between the two centroids is set to be within 300 pixels, so that two light spots are easy to distinguish, the field of view is not large, and the frame frequency of the camera can be improved.
(7) The invention uses the camera to calculate the centroid of the light spot, does not need to transmit the image to the control module, and has fast centroid calculation and small data transmission quantity.
Example 2
As shown in fig. 4, the method of using the all-weather atmospheric coherence length measuring system described in embodiment 1 includes the following steps:
s1, powering on the system, wherein the horizontal rotation angle and the pitching angle of the atmospheric coherence length instrument are both driven by the driving assembly to be 0 degree; the control module configures the exposure parameters of the camera 2 into the camera 2 from the data input end of the atmospheric coherence length instrument; the control module acquires GPS information of the position of the system and corresponding time information from the data acquisition end;
s2, the control module calls the internally stored star map information, according to the GPS information and the corresponding time information, the star with the highest brightness in the range that the pitch angle of the atmospheric coherence length instrument is not less than 30 degrees is selected from the star map information, and the position of the star is determined; the star position can be determined by referring to the calculation of the star position in chapter ninth in spherical astronomy. The control module calculates the horizontal rotation angle and the pitching angle of the atmospheric coherence length instrument, so that the imaging position is positioned in the center of the camera 2. In particular, the method comprises the following steps of,
s21, the control module controls the driving component by calculating the horizontal rotation angle and the pitching angle of the atmospheric coherence length instrument to enable the telescope 1 of the atmospheric coherence length instrument to initially aim at the star;
s22, imaging the light of the stars incident into the telescope 1 through the system, and controlling the driving assembly to enable the telescope 1 of the atmospheric coherence length instrument to accurately aim at the stars until the imaging position is located at the center of the camera 2 according to the position of the imaged light spot in the camera 2 through the control module.
S3, the stars obtain two light spots in the
camera 2, the position of the mass centers of the two light spots is calculated by the
camera 2, and the calculation formula of the mass centers is
Wherein x, y are coordinate values, I (x), I (y) are light intensity in x, y directions. Judging whether the distance between the two centroid positions exceeds a set value of 300 pixels or not, wherein the allowable error is 20 pixels, and when the distance exceeds the set value, sending a rotation signal to a control module, and controlling a focusing mechanism 3 to carry out focusing by the control module;
s4, the control module determines the running track of the stars according to the star map information, the atmospheric coherence length instrument moves according to the motion track by controlling the driving assembly, the control module obtains the centroid position of the image calculated by the camera 2 in the process of moving according to the motion track, and then the control module calculates the corresponding coherence length;
s5, the control module stores the coherence length and the corresponding time information, GPS information, pitch angle information and star type;
s6, the control module determines the running track of the stars according to the star map information and enables the atmospheric coherence length instrument to move according to the running track by controlling the driving assembly;
s7, when the pitch angle of the atmosphere coherence length instrument is smaller than the set range in the step S2, the control module reselects the stars with the highest brightness of the pitch angle of the atmosphere coherence length instrument within not less than 30 degrees on the star map information according to the current GPS information and the corresponding time information, and determines the positions of the stars; the control module calculates the horizontal rotation angle and the pitch angle of the atmospheric coherence length instrument, and the light of the selected star is imaged at the center of the camera 2 in the step, and the step returns to step S4.
The invention is not to be considered as limited to the specific embodiments shown and described, but is to be understood to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.