Higher-order spectra measurement techniques of termite emissions. A characterization framework ∗

A higher-order frequency-domain characterization of termite activity (feeding and excavating) has been performed by means of analyzing diagonal slices of the bispectrum and the trispectrum, with the main goal of reducing subjectiveness in the task of detecting a possible infestation in a noisy measurement scenario. Five sets of signals of different qualities were acquired using two different accelerometers: an insect-oriented model and a seismic-waves sensor. We conclude that it is possible to establish a higher-order pattern associated to the termite emissions, and resulting from the impulsive response of the sensor and the body or substratum through which the emitted waves propagate.