POLYNOMIAL SMOOTHING OF SPECTRA

Abstract

A simplified smoothing formula for filtering data by a running least squares fit of sampled data points to polynomials of any desired degree will be given. The formula should be appropriate for programming on a small computer. It will be shown that the transfer functions for these filters follow the pattern previously described for the quadratic $filters.^{1}$ Hence, by using them a multiple number of times, one may obtain a transfer function with essentially zero transfer of high frequencies. Simultaneously one may obtain a sharper frequency cutoff than previously described.