Methods And Systems For Filtering And Estimating Characteristics Of An Input Signal Using A Tracker Comprising A Prism Filter

A method of estimating characteristics of an input signal comprises inputting the input signal into a first tracker to determine a first estimate of characteristics of the input signal, and determining a normalised signal from the input signal. The normalised signal is input into a second tracker to determine a second estimate of characteristics of the input signal. At least one of the first tracker and the second tracker comprises or is derived from at least one Prism filter. Further, a method of filtering an input signal is provided. The method comprises applying a sequence of one or more filter stages to the input signal to generate respective downsampled signals. A tracker stage is applied to the output of the final filter stage to determine one or more characteristics of the input signal.