Vector diffraction theory-based Fresnel diffraction optical system imaging simulation method

Abstract

The invention discloses a vector diffraction theory-based Fresnel diffraction optical system imaging simulation method. The method comprises the following steps of: 1, segmenting an original image into a plurality of ring image blocks with same ring widths on the basis of a concentric circle blocking thought; 2, calculating an MTF of each ring by utilizing a time domain finite difference method (FDTD); and 3, carrying out low-pass filter on the image blocks by utilizing the MTF of each ring, and adding noise. The method is suitable for simulating and estimating imaging quality of optical systems which take diffraction mirrors as main mirrors, and is capable of obtaining simulated images with diffraction optical characteristics such as low MTF, low SNR, large-size PSF space shift change, providing support for optimum design of diffraction optical systems and research and verification of image processing algorithms, and filling the gaps of current diffraction optical imaging quality finesimulation modeling theoretical methods.

Description

technical field [0001] The invention belongs to the technical field of optical imaging simulation, and in particular relates to an imaging method of a Fresnel diffractive optical system, in particular to an imaging simulation method of a Fresnel diffractive optical system based on vector diffraction theory. Background technique [0002] The simulation estimation of optical remote sensing imaging quality has important guiding significance and application value in the prediction of remote sensing tasks such as reconnaissance, surveying and mapping, surveillance, imaging system optimization design and performance evaluation, and image processing algorithm verification. With the continuous improvement of space resolution requirements for high-orbit surveillance, there is an urgent need for space optical payloads to have the characteristics of super large aperture, light weight, short processing cycle, and low cost. Traditional reflective or refractive imaging systems can no longe...

AI Technical Summary

Problems solved by technology

With the continuous improvement of space resolution requirements for high-orbit surveillance, there is an urgent need for space optical payloads to have the characteristics of super large aperture, light weight, short processing cycle, and low cost. Traditional reflective or refractive imaging systems can no longer fully meet these requirements. Requirements, and diffractive optical imaging technology can overcome this limitation, so it is urgent to study the simulation model and method of imaging quality for optical diffractive imaging system

However, according to the existing literature, most of the research in this area is aimed at reflective or refractive systems, and there are few reports on the image quality degradation mechanism, simulation models and methods of diffractive imaging systems.

Compared with the traditional payload, the image quality degradation of the diffractive optical imaging system is more serious, and the transfer function (MTF) and signal-to-noise ratio (SNR) of the image are lower, especially the point spread function (PSF) at different fields of view. The large spatial variability clearly cannot be simulated with traditional reflective or refractive system models

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