Four parameter sine fit with less than one cycle of data

Abstract

- When an ADC acquires sine-wave dafa and the record length confains less fhan one cycle of fhe sine wave, and fhe frequency of fhe sine-wave or the sampling frequency are not known exacfly, the standard four parameter curve-fir algorithm does nof always converge. A technique, usingpolynomial~fting, is demonstrafed The algorithm extracfs the four paramefers when the dafa sef includes from 20% fo 100% of a cycle of fhe sine wave. The sensitivify to noise and harmonic disforfion is examined The resulfs converge fo near the correcf values, but fhere are noise and harmonic disforfion sensifivifies.