A Refractive-Diffraction Hybrid Spectral Encoding Imaging System and Method

Abstract

The invention discloses a spectral encoding imaging system and method of refractive diffraction mixing. In the system of the present invention, the coded diffraction element, the positive lens and the detector are placed in sequence along the optical axis, and the uncoded end face of the coded diffraction element is in contact and fixedly connected with the positive lens to form a refractive-diffraction hybrid module, which is placed at the focal plane of the refractive-diffraction hybrid module. There is a detector; the incident light is condensed by the coded diffractive element and the positive lens and then imaged on the detector. Methods The above system was used to calibrate and obtain the point spread function in different bands, and obtain the initial image of spectral aliasing. The hyperspectral image reconstruction network algorithm was used to process the initial image of spectral aliasing to obtain the hyperspectral image in different bands. The refracting-diffraction hybrid module of the invention effectively shortens the back intercept of the imaging system, reduces the point spread function scale of the imaging system in each wavelength band while ensuring a short back intercept, improves the spatial resolution of the imaging system, and the applicable range of the spectrum band Wide and robust.

Description

technical field [0001] The invention belongs to a spectral coding imaging system and method of spectral imaging technology, and in particular relates to a spectral coding imaging system and method of refraction and diffraction mixing. Background technique [0002] Spectral imaging technology is a new type of technology that utilizes single or multiple spectral channels for spectral data acquisition and processing, image display and analysis and interpretation. Because spectral imaging combines spectroscopy and imaging technology, it has the advantages of both spectroscopy and imaging, and currently plays a vital role in aerospace, remote sensing detection, military reconnaissance and other fields. [0003] At present, the spectral imaging system mainly faces the following technical difficulties: First, the structure of the push-broom and swing-broom systems is too large and complex to meet the requirements of miniaturization and light weight in the aviation and aerospace fie...

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Problems solved by technology

[0003] At present, the spectral imaging system mainly faces the following technical difficulties: First, the push-broom and swing-broom system structures are too large and complex to meet the miniaturization and lightweight requirements of the aviation and aerospace fields

Second, due to the limitations of the system, both push-broom and swing-broom take time, resulting in the inability to obtain spectral images at the same time and lack of timeliness

However, the structure of the diffraction element design is more complicated, which is not conducive to processing, and processing errors will affect the reconstruction effect of the image

At the same time, the calibration of the point spread function of the system requires a large space and an excellent darkroom environment, which increases the difficulty of the calibration of the point spread function and affects the accuracy of the calibration.

And the spectral range of the system is limited to 420nm-660nm, the spectral band is not wide enough

[0006] In the above-mentioned compact snapshot spectral imaging system based on rotational diffraction, the diffraction element has a limited aperture, a small luminous flux, and a long exposure time. On the premise of keeping the F number of the system unchanged, increasing the aperture increases the light flux and at the same time Bringing problems such as increased focal length, which limits the spatial resolution and hyperspectral imaging frame rate of the system

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