Abstract: A method and a system for measuring the energy of a signal is based on the use of a time-frequency distribution using as kernel a bi-dimensional filter having compact support properties. The two-dimentional filter is applied to the two-dimensional correlation function of the signal to be analyzed. The system includes an acquisition unit for providing samples of the signal, a Hilbert transformer for producing an alytical signals from those samples, and a local correlator for computing the convolutions of a kernel derived from a Gaussian kernel and having compact support properties and instantaneous autocorrelation functions so as to yield generalized instantaneous autocorrelation functions, and a Fourier transformer for determining information related to the energy of the signal from the derived generalized instantaneous autocorrelation functions. The method and system allows a better reduction of false energy observances (interference) while providing good resolution in time and in frequency.