CN201348508Y - Standard starlight simulator and stray light PST optical detection system containing the simulator - Google Patents

Abstract

The utility model relates to a standard starlight simulator and a stray light PST optical detection system containing the simulator. The standard starlight simulator includes a light source, a variable aperture, a homogenizer, a star point plate and a collimation system; The aperture is set on the incident light path of the light source; the homogenizer is set on the output light path of the iris diaphragm; the star point plate is set on the light homogenizer; the collimation system is set on the output light path of the star point plate. The utility model provides a standard starlight simulator which can greatly expand the range of simulated magnitude, can accurately measure and calibrate in an extremely weak light environment, and has high measurement accuracy, and a stray light PST optical detection system containing the simulator.

Description

Standard starlight simulator and stray light PST optical detection system containing the simulator

technical field

The utility model relates to a standard starlight simulator and a stray light PST optical detection system containing the simulator.

Background technique

The starlight simulator is a standard source of measurement benchmarks, mainly for the purpose of establishing a standard magnitude and luminosity. As a ground calibration device, the star simulator simulates the weak star illumination, star angle diameter and spectral characteristics, and is used to test and calibrate the sensitivity of stars, satellite detectors and star sensors to space targets of different magnitudes and spectral characteristics. It meets the needs of ground simulation tests of starlight detectors and star sensors. At present, the star simulator has become a key instrument for ground calibration tests of starlight detectors and star sensors.

As the requirements for the detection capability and accuracy of starlight detectors are getting higher and higher, this will inevitably put forward higher requirements for the ground calibration equipment star simulator. Judging from the research in related fields at home and abroad, the following methods are mainly used for the generation of weak light in foreign countries:

1) A pinhole is placed on the focal plane of the collimator, and a simulated star point image is generated after the light source is illuminated. This scheme cannot be quantitatively calibrated, and the simulated star magnitude is low;

2) Use an optical fiber to guide the light to the focal plane of the collimator, adjust the luminous flux by adding a neutral attenuator, and simulate the starlight of -2 to 8th magnitude. This scheme cannot be quantitatively calibrated, and the optical fiber is used to guide the light. Factors such as bending and attenuation have a great influence on the system accuracy.

3) Using advanced liquid crystal light valve technology, the simulated star map given by the computer is sent to the high-resolution LCD screen in real time, and the lighting system illuminates the LCD screen to generate simulated star points, which are then sent to the star sensor by the light pipe above to complete a comparative measurement of its star map position. This method has high real-time performance and flexible patterns, but the resolution of the LCD screen is low, the contrast is low, the simulated angular diameter is large, and it cannot be calibrated quantitatively.

However, most of the scientific research institutions in China adopt liquid crystal light valve technology, but generally speaking, the magnitude simulated by this technology is still low, which is difficult to meet the simulation of weak starlight with high magnitude, and the extremely weak light situation There are great difficulties in the calibration below.

The level of stray light is an important indicator of the optical system. Stray light reduces the contrast and signal-to-noise ratio of the image plane of the optical system, and produces spots on the image plane, which affects the quality of the optical system. In severe cases, it will cause system failure. The level of stray light directly affects the improvement of detection capability, so the design and detection of stray light in the optical system is imperative. From the research in related fields at home and abroad, the evaluation and inspection of the level of stray light is mainly solved by testing the two parameters of point source transmittance (PST) and stray light coefficient (V). The point source transmittance (PST) is defined as: PST(θ)=E _d (θ)/E. where _Ed (θ) is the irradiance on the detector due to the source at an off-axis angle θ; E is the irradiance at the input aperture perpendicular to the point source.

Whether it is domestic or foreign, it has not been well satisfied to simultaneously simulate the weak starlight of higher magnitudes and solve the quantitative calibration in the case of extremely weak light.

Utility model content

In order to solve the above-mentioned technical problems in the background technology, the utility model provides a standard starlight simulator which can greatly expand the range of simulated magnitudes, can accurately measure and calibrate in extremely weak light environments, and has high measurement accuracy and contains the simulated Stray light PST optical detection system for detectors.

The technical solution of the utility model is: the utility model provides a standard starlight simulator. system; the iris is arranged on the incident optical path of the light source; the homogenizer is arranged on the output optical path of the iris; the star point plate is arranged on the homogenizer; the collimation system Set on the output light path of the star point board.

The above-mentioned standard starlight simulator also includes a photometric measurement device, and the spectral measurement device is arranged on the homogenizer.

The aforementioned photometric device is an illuminance meter, a photocell or a spectroradiometer.

Star point holes are arranged on the above star point plate, and there are one or more star point holes.

The above-mentioned light source is a tungsten halogen lamp or a xenon lamp light source.

The above-mentioned collimating system is an off-axis parabolic collimator, a refracting collimator or a telescopic optical system.

A stray light PST optical detection system containing a standard starlight simulator, its special feature is: the optical detection system includes a standard starlight simulator, an object stage, a photodetector, and an optical trap; the photodetector is arranged in a standard The output light path of the starlight simulator; the stage is arranged between the photodetector and the standard starlight simulator.

The above-mentioned optical detection system further includes an optical trap, and the optical detection system is entirely placed in the optical trap.

The above-mentioned stage is a two-dimensional stage.

The photodetector described above is a high-sensitivity photodetector.

The above-mentioned light trap is a black cloth, a hood, or a camera obscura.

The utility model has the advantages of:

1. The range of simulated stars can be greatly expanded. The utility model adopts the variable aperture to adjust the luminous flux. Compared with the adjustment of the luminous flux by using the combination of the neutral attenuation sheet group, the dynamic range of the continuous dimming amount of the variable aperture is large, and the range and precision of the simulated magnitude are improved. At the same time, the utility model also adopts a star point plate and a collimator to simulate starlight at infinity. improve. Different star point boards or small holes can be replaced to meet different needs, and multiple star point holes can be opened on one star point board to realize star map simulation, which greatly expands the range of simulated stars.

2. It can be accurately measured and calibrated under extremely weak light conditions. The utility model adopts a light homogenizer to ensure the uniformity of light distribution in the light homogenizer, and at the same time cooperates with photometric equipment so that the light quantity at the exit can be accurately measured. It solves the problem of measurement calibration without low-light standards very well.

3. High measurement accuracy. The utility model cooperates with a standard high-sensitivity detector, and can perform stray light PST test on a long focal length optical system, and the test dynamic range is large, and the dynamic range can reach 10 orders of magnitude. By adding filters, the system can perform full-color and single-color PST tests, and cross-calibration can be performed by changing different small holes. The calibration accuracy is high, and it is less affected by environmental factors such as temperature, and can be conveniently and flexibly controlled by the computer. Manage the measurement and calibration process.

Description of drawings

Fig. 1 is the preferred structural representation of the standard star system provided by the utility model;

Fig. 2 is a structural schematic diagram of the stray light PST optical detection system provided by the utility model.

Detailed ways

Referring to Fig. 1, the utility model provides a kind of standard starlight simulator, and this standard starlight simulator comprises light source 1, iris diaphragm 2, homogenizer 3, star spot plate 5 and collimation system 6, iris diaphragm 2 is set on the incident light path of the light source 1; the homogenizer 3 is set on the output light path of the iris 2; the star point plate 5 is set on the light homogenizer 3; the collimation system 6 is set on the star point plate 5 output light path.

In addition to the above devices, the standard starlight simulator also includes a photometric device 4, which is arranged on a certain opening of the homogenizer 3.

The star point plate 5 can be provided with a star point hole, and there are one or more star point holes.

The light source system 1 can use a DC stabilized current electric light source such as a tungsten halogen lamp, a xenon lamp, and the like.

The collimation system 6 is an off-axis parabolic collimator, a refracting collimator or a telescopic optical system, and various photographic lenses.

The light generated by the light source 1 through the light source system enters the homogenizer 3 through the iris 2, and the amount of light entering is variable by adjusting the iris 2, so as to realize the change of the brightness at the exit of the homogenizer 3, thereby simulating Different starlight illuminance.

A photometric device 4 is installed on the homogenizer 3. Since the light distribution in the homogenizer 3 is uniform, the photometric device can measure light characteristics and observe changes in performance such as color temperature to provide feedback, and at the same time solve the problem of extremely weak light Calibration problem. The light passes through the star point plate 5 at the exit of the homogenizer 3 and irradiates the collimation system 6 to simulate starlight at infinity. The magnitude is greatly improved, and higher magnitudes can be extrapolated. Very good simulation of high magnitude faint light. Simultaneously, a plurality of star-point holes can be opened on the star-point plate 5, so that the simulation of multi-star-point diagrams can be realized.

Calibration method: according to the following formula:

$\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; T</span>}$

Where d is the diameter of the star point hole, F is the focal length of the collimation system 6 , and L is the exit brightness of the homogenizer 3 , which is measured by the photometric device 4 . T is the optical transmittance of the collimation system.

While providing a standard starlight simulator, the utility model also provides a stray light PST optical detection system containing a standard starlight simulator. The optical detection system includes a standard starlight simulator, a stage 8 and a photoelectric detection system device 9, the photodetector 9 is arranged on the output optical path of the standard starlight simulator; the stage 8 is arranged between the photodetector 9 and the standard starlight simulator. The optical detection system may also include a light trap 10 and a color filter 7, the optical detection system is placed in the light trap 10 as a whole, and the color filter 7 is placed at the exit of the homogenizer.

The stage mentioned in the optical detection system is a two-dimensional stage, which can be pitched and rotated horizontally in two dimensions.

The photodetector 9 is a high-sensitivity photodetector. The high-sensitivity photodetector is a high-sensitivity photodetector whose minimum detectable light power should be less than 1.0×10 ^-10 w/m ² .

The light trap 10 is a black cloth, a light shield or a black box.

When the stray light PST optical detection system provided by the utility model is performing the PST test, the optical system to be tested is first placed on the stage 8, and the star point plate 5 is replaced with a small hole with a larger diameter, so that the iris 2 up to the fully open state to produce maximum incident light illuminance. The light emitted by the star simulator enters the optical system under test, and it is equipped with a high-sensitivity detector 9, which can not only perform PST testing, but also add a filter 7 at the exit of the homogenizer 3 to adjust the optical system under test in multi-color or monochrome. Measure the stray light characteristics under colored light.

Claims (11)

1, a kind of standard starlight simulator, it is characterized in that: described standard starlight simulator comprises light source, iris, homogenizer, star plate and collimation system; On the optical path; the homogenizer is arranged on the output optical path of the variable diaphragm; the star point plate is arranged on the light homogenizer; the collimation system is arranged on the output optical path of the star point plate. 2. The standard starlight simulator according to claim 1, characterized in that: the standard starlight simulator further comprises a photometric measurement device, and the spectral measurement device is arranged on the homogenizer. 3. The standard starlight simulator according to claim 2, characterized in that the photometric device is an illuminance meter, a photocell or a spectroradiometer. 4. The standard starlight simulator according to claim 1, 2 or 3, characterized in that: the star point plate is provided with a star point hole, and there are one or more star point holes. 5. The standard starlight simulator according to claim 4, wherein the light source is a tungsten-halogen lamp or a xenon lamp. 6. The standard starlight simulator according to claim 5, wherein the collimation system is an off-axis parabolic collimator, a refracting collimator or a telescopic optical system. 7. A stray light PST optical detection system containing the standard starlight simulator of claim 1, characterized in that: said optical detection system comprises a standard starlight simulator, an object stage, a photodetector, and an optical trap; The photodetector is arranged on the output light path of the standard starlight simulator; the stage is arranged between the photodetector and the standard starlight simulator. 8. The stray light PST optical detection system of the standard starlight simulator according to claim 7, characterized in that: the optical detection system further comprises an optical trap, and the optical detection system is entirely placed in the optical trap. 9. The stray light PST optical detection system of the standard starlight simulator according to claim 8, wherein the stage is a two-dimensional stage. 10. The stray light PST optical detection system of the standard starlight simulator according to claim 7, 8 or 9, characterized in that: the photodetector is a high-sensitivity photodetector. 11. The stray light PST optical detection system of the standard starlight simulator according to claim 10, characterized in that: the optical trap is a black cloth, a hood or a dark box.

Images