A coding method for a coded aperture spectral imager

Abstract

The invention discloses a coding method of a coded aperture spectral imager. The method comprises the following steps: determining the coding quantity of a coded aperture according to the view field of an optical system, the focal length and the pixel size of a detector; designing N groups of one-dimensional vectors according to a preset luminous flux and the coding quantity of the coded aperture, performing orthogonal transformation on the N groups of one-dimensional vectors respectively, performing inversion operation, eliminating the one-dimensional vectors comprising infinitely great elements or infinitely small elements in a matrix obtained by the inversion operation to obtain M groups of one-dimensional circulating vectors, wherein M is smaller than N; performing self-circulation matrix processing on the M groups of one-dimensional circulating vectors, and performing inverse transformation of orthogonal transformation on each newly-generated matrix to finish two-dimensional orthogonal transformation self-circulation coding. Through the disclosed coding method, the practicability of the coded aperture spectral imager is improved, and optical field transmission and modulation of a multiband spectral large-area-array imaging space can be provided.

Description

technical field [0001] The invention relates to the technical field of spectral imaging, in particular to an encoding method for an encoding aperture spectral imager. Background technique [0002] The spectral imager can acquire the two-dimensional spatial image and one-dimensional spectral information of the target at the same time. It can not only directly reflect the geometric shape of the measured target, but also provide the physical and chemical properties of the target. It is a detection method combining graphs and spectra. Since the 1980s, spectral imaging technology has been widely used in aerospace remote sensing imaging, carried by aircraft, and has made remarkable achievements in the fields of mineral and oil resource detection, water quality and air pollution monitoring, precision agriculture and forestry. At present, this technology has gradually penetrated into civilian fields such as biomedicine, artwork anti-counterfeiting identification, food safety monitor...

AI Technical Summary

Problems solved by technology

[0006] However, due to the grating dispersion itself, the slit position of the light modulation is also very precise. If the traditional Hadamard transformation coded aperture is used, it will inevitably cause spectral aliasing of the imaging fringes in each band. If the coded aperture is not corrected accordingly And changes will be very detrimental to the light field modulation performance of the overall spectral imager, which will eventually be reflected in the imaging results, and will greatly increase the difficulty and accuracy of restoration and inversion; at the same time, the existing coded aperture grating dispersion spectral imaging The coded aperture used by the instrument is generally a small field of view to modulate the light field, and the target spectrum restoration will also be small area range

In the face of large-scale wide imaging has not yet been involved, this obviously affects the range and timeliness of the application of the Hadamard transform spectral imager

However, the Hadamard transform spectral imager using the prism dispersion type has its own spectral line bending distortion and nonlinear dispersion effect due to the prism dispersion; moreover, it has not been seen in the patents and literature reports of the traditional Hadamard transform spectral imager at present. Provide targeted coded aperture solutions

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