Frequency determination of weak sinusoids buried in noise

A simple method for estimating the frequency of a sinusoidal signal highly contaminated with noise is described in this paper. The proposed method uses digital signal processing techniques such as least squares smoothing, numerical integration, windowing, and sampling rate reduction for filtering out the noise with only simple computational needs. The frequency is estimated by counting the number of maxima and minima of the resulting signal. For sinusoidal signals which can be sampled at a high rate relative to the Nyquist limit, this method is particularly attractive, and gives good estimates even for very low values of signal-to-noise ratio (SNR).