System and method for detecting twin by photoelectric telescope in near-sun region

Abstract

The invention provides a near-sun region photoelectric telescope detection twin system and method, which are used for simulating the near-sun region detection condition in a telescope view field. Comprising a sky background brightness simulation module which can interact with a photoelectric telescope, a forward scattering type visibility meter and a sky background radiance measurement instrument and is used for simulating and generating the sky background brightness; the limit detection capability calculation module is used for calculating the limit detection capability of the photoelectric telescope when the external environment and the system parameters are known; and the field-of-view detection display module is used for simulating distribution conditions of the observation target and the fixed star after the influence of the sky background is eliminated.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric detection, and in particular to a near-solar region photoelectric telescope detection twin system and method. Background Art

[0002] With the vigorous development of aviation technology, human beings' demand for space exploration has gradually increased. The current photoelectric telescope, as an important instrument for photoelectric tracking and measurement, is particularly important. However, for daytime detection, due to the influence of complex strong sky background brightness, the detection capability of photoelectric telescopes is reduced, the observable time of targets is reduced, and the observation opportunities, effective observation data and observation efficiency of telescopes are greatly reduced. The main interference of daytime detection comes from the complex atmospheric environment and solar scattering. For the far sun region, the sky background brightness can be approximately regarded as a constant value, but for the near sun region, the sky background brightness will change complexly with the change of position. Research on the near sun region and the construction of the photoelectric telescope detection model for the near sun region will help solve the problem of difficult daytime detection and low detection efficiency.

[0003] In the context of the rapid development of digital technology, people have put forward new requirements for the digital level of optoelectronic telescope equipment. Building a digital twin system for optoelectronic telescopes and improving the digital level of telescopes have gradually become the focus of current technological exploration. The construction of the detection twin system of the optoelectronic telescope has the following significance for the optoelectronic telescope system:

[0004] Before the detection mission is carried out, the simulated atmospheric environment parameters and telescope system parameters are input to predict the detection situation of the telescope in advance, simulate the detection situation of the photoelectric telescope, prevent and solve the problems that will be faced in the detection, and evaluate the feasibility of the mission execution;

[0005] During the detection mission, virtual and real interactions are carried out with the physical entity of the telescope to reflect the real-time working status of the telescope and improve the overall digitalization and intelligence level of telescope detection;

[0006] After the detection mission is completed, the experimental data generated by the mission will be further mined and its physical significance will be deeply analyzed to provide strong support for further research on the changes in telescope detection parameters and physical laws, evaluate the working status of the telescope equipment, and facilitate the full life cycle management of the telescope equipment.

[0007] In summary, building a detection twin system for the near-Sun region optoelectronic telescope can effectively solve the problems of insufficient digitization of current optoelectronic equipment, difficulty in obtaining sky background brightness, especially the sky background brightness in the near-Sun region, and the impact of complex sky background brightness changes on detection efficiency during daytime detection. It can effectively promote the execution of optoelectronic detection tasks. Summary of the invention

[0008] The technical problem to be solved by the present invention is: in view of the difficulty in detection of photoelectric telescopes in the near-solar region, a detection twin system model of a photoelectric telescope in the near-solar region is provided to simulate the detection situation within the telescope's field of view.

[0009] The technical solution adopted by the present invention is: a near-sun region photoelectric telescope detection twin system, including: a skylight background brightness simulation module, a limit detection capability calculation module, and a field of view detection display module;

[0010] The skylight background brightness simulation module is used to simulate the skylight background brightness of the near-sun area and the entire sky area on that day;

[0011] The limit detection capability calculation module is used to calculate the limit detection capability of the photoelectric telescope when the external environment and the photoelectric telescope system parameters are known;

[0012] The field of view detection and display module is used to simulate the distribution of observed targets and stars after eliminating the influence of sky light background.

[0013] The present invention also proposes a method for detecting twins using a near-solar region photoelectric telescope, comprising the following steps:

[0014] S1, skylight background brightness simulation module measures the atmospheric extinction coefficient through the forward scattering visibility meter , the sky background radiance measuring instrument measures the fixed point sky background brightness , the skylight background brightness near the sun is obtained by calculation ;

[0015] S2, the limit detection capability calculation module is based on the sky background brightness The detection capability limit of the near-solar region is obtained by using the system parameters of the optoelectronic telescope;

[0016] S3, the field of view detection display module, based on the calculation of the number of photons in the limit detection capability calculation module, simulates the distribution of observation targets and stars in the near-solar region after eliminating the influence of the sky light background, and completes the simulation of the telescope field of view detection.

[0017] In summary, compared with the prior art, the near-solar region photoelectric telescope detection twin system and method provided by the present invention has the following advantages:

[0018] The algorithm of the present invention is simple to calculate and can be used for pre-task prediction, in-process status monitoring and post-data processing of optoelectronic telescopes. The detection twin system model of the optoelectronic telescope can be used for pre-prediction before the execution of the detection task and to evaluate the feasibility of the task execution; the virtual-real interaction during the task execution, real-time monitoring and reflection of the working equipment of the optoelectronic detection system; the data processing after the task execution, in-depth excavation of its physical meaning and the law of parameter changes, to facilitate the full life cycle management of the equipment. Constructing the detection twin system model of the near-solar region optoelectronic telescope is of great significance for improving the digitalization and intelligence level of the optoelectronic telescope and facilitating the full life cycle management of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structural composition of a detection twin system;

[0020] Figure 2 It is a flow chart of the detection twin method. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above-mentioned purpose, the present invention adopts the following technical scheme.

[0022] The present invention provides a near-sun region photoelectric telescope detection twin system, such as Figure 1 As shown, it includes: a skylight background brightness simulation module, a limit detection capability calculation module and a field of view detection display module. The skylight background brightness simulation module includes a forward scattering visibility meter and a sky background radiance measuring instrument, which are used to generate the skylight background brightness of the near-sun region and the entire sky; the limit detection capability calculation module is composed of an optoelectronic telescope and a computer, which is used to generate the limit detection capability of the optoelectronic telescope in the near-sun region according to the skylight background brightness of the near-sun region and the parameters of the system itself; the field of view detection display module, based on the calculation of the number of photons in the limit detection capability calculation module, simulates the distribution of the observed targets and stars after eliminating the influence of the skylight background.

[0023] Based on the above-mentioned near-solar region photoelectric telescope detection twin system, the present invention also provides a near-solar region photoelectric telescope detection twin method, such as Figure 2 As shown, it includes the following steps: S1, the skylight background brightness simulation module measures the atmospheric extinction coefficient through a forward scattering visibility meter , the sky background radiance measuring instrument measures the fixed point sky background brightness , the skylight background brightness near the sun is obtained by calculation ; S2, the limit detection capability calculation module obtains the limit detection capability of the near-solar region based on the sky background brightness and the photoelectric telescope system parameters; S3, the field of view detection display module, based on the calculation of the number of photons in the limit detection capability calculation module, simulates the distribution of observation targets and stars in the near-solar region after eliminating the influence of the sky background, and completes the simulation of the telescope field of view detection.

[0024] In step S1, specifically, first obtain the theoretical position of the sun target in the navigation reference coordinate system , They are azimuth and elevation, respectively. According to the azimuth and elevation of the telescope's observation direction, , get the angle between the observation direction and the incident direction of the sun :

[0025] (1)

[0026] Considering Rayleigh scattering and Mie scattering in the atmosphere, the total scattering equation is obtained: :

[0027] (2)

[0028] According to the sun's zenith angle and the zenith angle of the telescope , and the optical path caused by atmospheric scattering is obtained and :

[0029] (3)

[0030] (4)

[0031] According to the brightness of the sun , atmospheric extinction coefficient measured by forward scattering visibility meter The skylight background brightness is obtained by combining equations (2), (3) and (4): :

[0032] (5)

[0033] Use the sky background radiance meter to obtain the sky background brightness at a fixed point , and with By comparison, the fitting coefficients are and the final sky background brightness :

[0034] (6)

[0035] (7)

[0036] Furthermore, the sky background brightness obtained by inputting the sky background brightness simulation module , use the limit detection capability calculation module in step S2 to obtain the system parameters of the photoelectric telescope itself and the external environment parameters: dark current electronic noise , readout electronic noise , the quantum efficiency of the detector for sky background light ; Planck constant ; Speed ​​of light ; Average wavelength , the area of ​​a single pixel of the detector , exposure time ; Average transmittance of optical system ; Main mirror obstruction ratio ; Optical system aperture ; Optical system focal length ; Spectral filter transmittance coefficient to background spectrum , calculate the background signal photoelectron noise :

[0037] (8)

[0038] According to the photon flux density of 0 magnitude starlight , star magnitude , average atmospheric transmittance , Photoelectric telescope system parameters: quantum efficiency of detector to target ; Number of pixels occupied by the observed target ; Spectral filtering transmittance coefficient of target spectrum , calculate the number of photoelectrons of starlight signal :

[0039] (9)

[0040] According to the telescope detection signal-to-noise ratio threshold , equations (8) and (9) are used to calculate the limiting detection magnitude of the photoelectric telescope: :

[0041] (10)

[0042] According to environmental parameters: Boltzmann constant , the blackbody temperature of the sun , average wavelength , the solar surface area , the average distance between the Earth and the Sun ,calculate ~ Band, solar irradiance to space targets :

[0043] (11)

[0044] According to the effective reflection area of ​​the space target , the average reflectivity of the target surface , the angle between the incident direction of sunlight and the normal direction of the target surface , the angle between the line connecting the detector and the target and the normal direction of the space target , the distance between the target and the photoelectric telescope system , the quantum efficiency of the detector to the target , calculate the number of photoelectrons received by each pixel of the detector as :

[0045] (12)

[0046] According to equation (11) and equation (8), the detection limit distance is calculated :

[0047] (13)

[0048] Based on the calculation of the number of photons in the above-mentioned limit detection capability calculation module, the distribution of observation targets and stars in the near-solar region after eliminating the influence of the sky light background is simulated to complete the simulation of the telescope field detection situation. Step S3 includes the following steps:

[0049] For stellar observation targets, according to equation (9) and the limiting detection magnitude , calculate the number of starlight photons :

[0050] (14)

[0051] Select the number of photons corresponding to the brightest object in the field of view , and its grayscale is recorded as ;

[0052] The background brightness grayscale value is recorded as 0, and the number of photons in the field of view is The gray value distribution of any observed target :

[0053] (15)

[0054] To sum up, compared with the prior art, the twin system and method for near-solar region photoelectric telescope detection provided by the present invention has the following advantages: the algorithm of the present invention is simple to calculate and can be used for pre-mission prediction, in-process status monitoring and post-data processing of photoelectric telescopes.

Claims

1. A near-solar region optoelectronic telescope detection twin system, characterized in that: include: Skylight background brightness simulation module, limit detection capability calculation module, field of view detection display module; The skylight background brightness simulation module is used to simulate the skylight background brightness of the near-sun area and the entire sky area on that day; The limit detection capability calculation module is used to calculate the limit detection capability of the photoelectric telescope when the external environment and the photoelectric telescope system parameters are known; The field of view detection and display module is used to simulate the distribution of observed targets and stars after eliminating the influence of sky light background.

2. The near-solar region optoelectronic telescope detection twin system according to claim 1, characterized in that: The sky light background brightness simulation module comprises a forward scattering visibility meter and a sky background radiance measuring instrument; the limit detection capability calculation module comprises a photoelectric telescope and a computer.

3. A method for detecting twins using a photoelectric telescope in a near-solar region, characterized in that: The steps include: S1, skylight background brightness simulation module measures the atmospheric extinction coefficient through the forward scattering visibility meter , the sky background radiance measuring instrument measures the fixed point sky background brightness , the skylight background brightness near the sun is obtained by calculation ; S2, the limit detection capability calculation module is based on the sky background brightness The detection capability limit of the near-solar region is obtained by using the system parameters of the optoelectronic telescope; S3, the field of view detection display module, based on the calculation of the number of photons in the limit detection capability calculation module, simulates the distribution of observation targets and stars in the near-solar region after eliminating the influence of the sky light background, and completes the simulation of the telescope field of view detection.

4. The method for detecting twins by a near-solar region photoelectric telescope as claimed in claim 3, characterized in that: Step S1 includes the following steps: S11, obtaining the theoretical position of the solar target in the navigation reference coordinate system, and obtaining the angle between the observation direction and the solar incidence direction according to the azimuth and elevation angle of the observation direction of the telescope; S12. Considering Rayleigh scattering and Mie scattering in the atmosphere, the total scattering equation is obtained; S13. The skylight background brightness of the near-sun region is obtained based on the brightness of the sun itself, the angle between the observation direction and the incident direction of the sun, the atmospheric extinction coefficient measured by the forward scattering visibility meter, and the total scattering equation; S14. Use a sky background radiance measuring instrument to obtain the sky background brightness of a fixed point, and compare it with the calculated sky background brightness of the near-sun region to obtain a fitting coefficient and a final sky background brightness.

5. The method for detecting twins by a near-solar region photoelectric telescope as claimed in claim 4, characterized in that: Step S2 includes the following steps: S21. According to the sky background brightness, obtain the system parameters of the photoelectric telescope itself and the external environment parameters, and calculate the background signal photoelectron noise; S22, calculating the number of photoelectrons of starlight signals according to the brightness parameters of the starry sky background and the parameters of the photoelectric telescope system; S23, calculating the limit detection magnitude of the photoelectric telescope according to the detection signal-to-noise ratio threshold, the background signal photoelectron noise, and the number of detected target photons; S24. Calculate the solar irradiance on the space target in a specific detection band according to the real-time or predicted environmental parameters; S25. Calculate the number of photoelectrons received by each pixel of the detector according to the space target detection data and the telescope system parameters; S26. Calculate the detection limit distance based on the solar irradiance on the space target and the number of photoelectrons received by each pixel.

6. The method for detecting twins by using a near-solar region photoelectric telescope as claimed in claim 5, wherein: Step S3 includes the following steps: S31. For a stellar observation target, the number of starlight photons of the stellar observation target is calculated according to the limiting detection magnitude; S32, select the number of photons corresponding to the brightest object in the field of view, and record its grayscale as ; S33, record the background brightness gray value as zero, and obtain the number of photons in the field of view as The gray value distribution of any observed target .

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