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

Abstract

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.