Beijing Institute of Technology

Jinmin Wu

Feng Zhang

Ran Tao

Mingfeng Lu

Zhen Guo

Kun Xiong

Xianggen Xia

A method, device and electronic apparatus for estimating physical parameters are disclosed. The method includes: reading a Newton's rings fringe pattern obtained by performing an interferometric measurement on a unit to be measured; obtaining the number and length of first-direction signals of the Newton's rings fringe pattern; performing, for each of the first-direction signals, a discrete chirp Fourier transform (DCFT) on the first-direction signal based on each first chirp rate parameter within a range of the length of first-direction signals, to obtain a first magnitude spectrum of an intensity distribution signal in a DCFT domain; determining a first chirp rate parameter and a first frequency parameter corresponding to a first magnitude peak value based on the first magnitude spectrum; and estimating the physical parameters involved in the interferometric measurement at least according to the first chirp rate parameter and first frequency parameter corresponding to the first magnitude peak value. In this way, the physical parameters involved in the interferometric measurement can be estimated with high accuracy and stably.

Method, device and electronic apparatus for estimating physical parameter by discrete chirp fourier transform

A physical parameter estimating method, a physical parameter estimating device, and electronic apparatus are disclosed. The method includes: reading a Newton's rings fringe pattern obtained by performing an interferometric measurement on a unit to be measured; downsampling the Newton's rings fringe pattern to obtain a downsampled Newton's rings fringe pattern; calculating a magnitude spectrum of an intensity distribution signal of at least one first-direction pixel set in the downsampled Newton's rings fringe pattern under each fractional Fourier transform (FRFT) order in a searching range of FRFT orders, the first-direction direction pixel set including a line of pixels in a first direction, the first direction being one of a row direction and a column direction of the downsampled Newton's rings fringe pattern; determining a matched order of the intensity distribution signal according to the calculated magnitude spectrums; and estimating a physical parameter involved in the interferometric measurement according to at least the matched order. Therefore, physical parameters of the unit to be measured can be estimated with high accuracy even in presence of noise and obstacles in the fringe pattern.

Physical parameter estimating method, physical parameter estimating device, and electronic apparatus using sampling theorem in the fractional fourier transform domain

A physical parameter estimating method, a physical parameter estimating device, and electronic apparatus are disclosed. The method includes: reading a Newton's rings fringe pattern of a unit to be measured; calculating a magnitude spectrum of an intensity distribution signal of at least one first-direction pixel set in the Newton's rings fringe pattern under each fractional Fourier transform (FRFT) order in a searching range of FRFT orders; determining a matched order of the intensity distribution signal according to the calculated magnitude spectrums; and estimating a physical parameter involved in the interferometric measurement according to at least the matched order. Therefore, physical parameters of the unit to be measured can be estimated with high accuracy even in presence of noise and obstacles in the fringe pattern.

Physical parameter estimating method that determines a matched order of an intensity distribution signal according to calculated magnitude spectrums and electronic apparatus

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Beijing, China

Jinmin Wu