Extraction of VLF-noise parameters

An algorithm is developed for real-time extraction of the parameters (power, impulsivity, and spikiness) of the Field-Lewinstein model for very-low-frequency (VLF) noise. This algorithm operates upon the first three moments of the noise envelope, which can be obtained by simple signal-processing hardware or software. The solution for the noise-model parameters in terms of the measured moments is based upon an iterative solution for one parameter and a quadratic solution for the other two. This technique has been used in an experimental VLF receiver as part of a system that adaptively adjusts the clipping level to ensure optimum suppression of noise impulses. >