Parameter Exploration for Spectral Estimation of Speckle Imagery in Modulation Transfer Function Measurements

摘要

Efforts to extend speckle-based focal plane array (FPA) modulation transfer function (MTF) measurementsbeyond the detector Nyquist frequency have unearthed challenging spectral estimation issues. In an attemptto better understand the task of speckle image spectral estimation, this paper explores the nuances of variousestimation techniques, making comparisons using both real speckle imagery and simulated data. Parameters andfeatures of the techniques investigated include number of image realizations, the size of image realizations andapplications of windows to speckle imagery spectral estimation. Real-world testing considerations such as laserstability and the challenge of collecting significant numbers of independent image realizations are addressed inthe analysis. Results show the advantage increasing the number of realizations has on estimation variance, therobustness of smaller realization segments when battling speckle field imagery spatial non-uniformities and thebenefits of windowing image segments with regards to power spectral density (PSD) estimation accuracy.