阅读说明：本技术 一种基于梯形镜片的多指定高度ccd成像系统及方法 (Trapezoidal lens-based multi-designated-height CCD imaging system and method ) 是由 靖旭 谭逢富 侯再红 何枫 张巳龙 秦来安 王浩 于 2020-07-03 设计创作，主要内容包括：本发明涉及大气光学探测和光学成像领域,尤其涉及一种基于梯形镜片的多指定高度CCD成像系统及方法,系统包括激光发射器和接收装置,所述接收装置包括接收望远镜和CCD相机,所述接收望远镜包括梯形镜片；所述激光发射器发出的激光经过所述梯形镜片反射,反射光被所述CCD相机的探测端捕捉；所述梯形镜片由n片反射面镀有高反膜的矩形镜片组成,所述矩形镜片呈阶梯状设置,其中n大于或等于2。该发明解决了原先的DCIM探测方案中为了使得CCD探测面与对于高度形成的焦平面相重合,需要对CCD的探测面进行特定角度的倾斜放置时,角度精度难以准确保证的问题。(The invention relates to the field of atmospheric optical detection and optical imaging, in particular to a multi-designated-height CCD imaging system and a method based on a trapezoidal lens, wherein the system comprises a laser transmitter and a receiving device, the receiving device comprises a receiving telescope and a CCD camera, and the receiving telescope comprises a trapezoidal lens; laser emitted by the laser emitter is reflected by the trapezoidal lens, and reflected light is captured by a detection end of the CCD camera; the trapezoidal lens is composed of n rectangular lenses with reflection surfaces plated with high-reflection films, the rectangular lenses are arranged in a step shape, and n is greater than or equal to 2. The invention solves the problem that the angle precision is difficult to accurately ensure when the detection surface of the CCD needs to be obliquely arranged at a specific angle in order to ensure that the detection surface of the CCD is coincident with a focal plane formed by the height in the original DCIM detection scheme.)

1. A multi-designated height CCD imaging system based on a trapezoidal lens is characterized by comprising a laser transmitter (1) and a receiving device (3), wherein the receiving device (3) comprises a receiving telescope (33) and a CCD camera (38), and the receiving telescope (33) comprises a trapezoidal lens (39);

after receiving scattered light generated by transmission in the atmosphere, the laser emitted by the laser emitter (1) is reflected by the trapezoidal lens (39), and the reflected light is captured by the detection end of the CCD camera (38);

the trapezoidal lens (39) is composed of n rectangular lenses with reflection surfaces plated with high-reflection films, the rectangular lenses are arranged in a step shape, and n is greater than or equal to 2.

2. The multi-designated height CCD imaging system based on trapezoidal lens of claim 1,

the laser transmitter (1) is spaced from the receiving device (3) by a certain distance;

laser generated by the laser transmitter (1) forms a collimated light beam through the transmitting beam expanding device (2) to be transmitted, and the receiving device (3) receives echo photons generated by the collimated light beam and images.

3. The multi-designated-height CCD imaging system based on the trapezoid lens as claimed in claim 1, wherein the laser emitter (1) is a continuous light laser emitter.

4. The CCD imaging system with multiple designated heights based on the trapezoid lens as claimed in claim 1, wherein the receiving device (3) for receiving the echo photons further comprises a light-gathering component arranged inside the receiving telescope (33), the light-gathering component comprises a support plate (35), an arc lens (36) and a reflective mirror (37), the support plate (35) is arranged in parallel with the primary mirror of the receiving telescope (33), a light-passing hole is formed in the middle of the support plate (35), the reflective mirror (37) is fixed between the primary mirror of the receiving telescope (33) and the support plate (35) through the light-passing lens, the reflective mirror (37) is parallel with the support plate (35), the reflective mirror (37) is positioned right above the light-passing hole, the arc lens (36) is arranged on both sides of the support plate (35), the lower bottom surface of the arc-shaped lens (36) is fixedly connected with the supporting plate (35), and the upper plane is arc-shaped.

5. The multi-designated-height CCD imaging system based on the trapezoid lens as claimed in claim 4, wherein the receiving device (3) further comprises a wedge lens (31) and a shielding cover plate (32), and the echo photons are transmitted through the wedge lens (31), pass through a sub-aperture (34) of a receiving telescope (33), pass through the arc lens (36) and the reflector (37), and are reflected to the clear aperture.

6. The multi-assigned height CCD imaging system based on a trapezoidal lens according to claim 5, characterized in that the spacing of the center points of the sub-apertures (34) is larger than a typical turbulent coherence length range, which is 4cm to 10 cm.

7. The multi-designated-height CCD imaging system based on the trapezoid lens as claimed in claim 4, wherein the trapezoid lens (39) is disposed inside the receiving telescope (33) and the angle of the trapezoid lens (39) is adjusted right below the light-passing hole, so that the echo photon beam passing through the light-passing hole is reflected to the detection surface of the CCD camera (38).

8. The method for using the trapezoidal lens based multi-designated height CCD imaging system of any one of claims 1 to 7, wherein the relative height and the angle of the trapezoidal lens is pre-calculated, and the pre-calculation steps are as follows:

s1: predetermining the number of imaging points and the relative height of each imaging point relative to the emission position;

s2: determining the actual image distance imaged by each imaging point according to the object image relation of each height point;

s3: and calculating and determining the relative height and angle of the trapezoidal lens according to the actual image distance of each imaging point, thereby compensating the imaging distance difference of the imaging points with different heights.

Technical Field

The invention belongs to the field of atmospheric optical detection and optical imaging, and particularly relates to a trapezoidal lens-based multi-designated-height CCD imaging system and method.

Background

During the transmission of laser in the atmosphere, random fluctuation can occur on the transmission path under the influence of atmospheric turbulence, and phenomena such as flicker, energy redistribution, random drift and the like can be generated on the light beam. The size of the atmospheric coherence length can reflect the strength of the laser influenced by atmospheric turbulence in the transmission process on the transmission path, and has great significance for the research of laser atmospheric transmission.

The equipment such as laser radar is comparatively direct and convenient equipment to the real-time measurement of atmosphere coherence length, and laser radar measures and can measure different routes to it is less influenced by weather conditions, and what represented has equipment such as difference image moving laser radar (DIM), difference light column image motion laser radar method (DCIM). The DIM method overcomes the interference of instrument jitter on the measurement of the atmospheric coherence length, but the DIM radar is easily disturbed by ground turbulence when the atmospheric coherence length is measured in a time-sharing manner. The DCIM radar is improved on the basis of the DIM radar, the defects of the DIM radar are overcome, the atmosphere coherence length information in a certain height range can be obtained simultaneously, the working mode of the DCIM radar transmits pulsed light, the initial detection height of the DCIM radar is determined through the gating function of the detector, the initial detection height has a sharp edge when the focal plane is imaged, the position relation between the beacon height and the beacon imaging is calibrated according to the sharp edge, the detection heights corresponding to other imaging points are determined, and the atmosphere coherence length data are obtained. The detection method is only suitable for pulsed light, and the possibility of error exists in the gating of the detector, so that the problem of determining the measurement height of the continuous laser is still a difficult problem.

Disclosure of Invention

In order to solve the problems that the angular precision of a CCD when a detection surface is obliquely arranged is difficult to accurately ensure and the detection height is determined when continuous light is used in the original DCIM detection scheme, the invention provides a trapezoidal lens-based multi-specified-height CCD imaging system and method. The invention adopts the following technical scheme:

a multi-designated-height CCD imaging system based on a trapezoidal lens comprises a laser transmitter and a receiving device, wherein the receiving device comprises a receiving telescope and a CCD camera, and the receiving telescope comprises the trapezoidal lens;

after receiving scattered light generated by transmission in the atmosphere, the laser emitted by the laser emitter is reflected by the trapezoidal lens, and the reflected light is captured by a detection end of the CCD camera;

the trapezoidal lens is composed of n rectangular lenses with reflection surfaces plated with high-reflection films, the rectangular lenses are arranged in a step shape, and n is greater than or equal to 2.

The method for using the trapezoidal lens-based multi-designated-height CCD imaging system is characterized in that the rectangular lenses are arranged in a step shape, the relative placement heights and angles of the lenses are calculated in advance, and the steps of the calculation in advance are as follows:

s1: predetermining the number of imaging points and the relative height of each imaging point relative to the emission position;

s2: determining the actual image distance imaged by each imaging point according to the object image relation of each height point;

s3: and calculating and determining the relative height and angle of the trapezoidal lens according to the actual image distance of each imaging point, thereby compensating the imaging distance difference of the imaging points with different heights.

The invention has the advantages that:

(1) the problem of in the original DCIM detection scheme, in order to make CCD detect the face and to highly forming focal plane coincide, when needing to carry out the slope of specific angle to the detection face of CCD and placing, the angle precision is difficult to guarantee accurately is solved.

(2) The invention solves the problem that in the original DCIM detection scheme, only pulse light can be used for detection by combining the gate control function of a detector due to the lack of the resolution capability of the imaging height of continuous light, and realizes the determination of the detection height of the continuous light.

(3) The invention can realize the simultaneous detection of a plurality of specified heights and has important significance for analyzing the effect of atmospheric turbulence in real time.

(4) The detection surface of the CCD camera can be vertically arranged, and the problems that the arrangement position of the CCD camera needs to form a certain angle in the prior art and the accuracy of the angle is difficult to guarantee are solved.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an atmospheric coherence length detection system suitable for use in the present invention;

FIG. 2 is a schematic cross-sectional view of a receiving device in an atmospheric coherence length detection system to which the present invention is applied;

FIG. 3 is a schematic diagram of the optical path of a single sub-aperture in an atmospheric coherence length detection system suitable for use in the present invention;

FIG. 4 is a schematic diagram of a CCD detector target surface in an atmospheric coherence length detection system to which the present invention is applied.

The notations in the figures have the following meanings:

1-laser emitter 2-emitting beam expanding collimation device

3-receiving device 31-wedge lens 32-shielding cover plate 33-receiving telescope

34-subaperture 35-supporting plate 36-arc lens 37-reflector 38-CCD camera

39-trapezoidal lens 4-processing computer.

Detailed Description