A method and device for extracting information from data representing a signal is disclosed. A set of data comprising a plurality of measurements of the signal generated at a first sampling rate is received from a sensor. A subset of the plurality of measurements is selected. A plurality of feature variables, each of which corresponds to a particular feature in a set of features that may be present in the signal are determined by deriving an underdetermined system of equations based on a selected basis function, the subset of the plurality of measurements, and the plurality of feature variables and corresponding features. The underdetermined system of equations is solved to determine a value for each feature variable using a non-linear optimization technique to minimize an L1 norm of the set of features. Feature information is stored in a storage medium.