THE FAST MATCHED-FILTER FOR GRAVITATIONAL-WAVE DATA-ANALYSIS - CHARACTERISTICS AND APPLICATIONS

We report on the application of a matched filter to the data of two-mo de resonant gravitational-wave antennas for the detection of burst sig nals, with reference to data obtained by direct acquisition, ie. witho ut going through lock-in amplifiers, sampled at relatively high speed. After a review of the basic model of resonant detectors, that include s a discussion of the signal and of the noise, we present a detailed m athematical derivation of the optimum filter matched to an input burst . We then analyze and discuss the performance of the matched filter as regards both the improvement of the signal-to-noise ratio and the obs ervation bandwidth, also considering the adaptive realization of the f ilter, based on the actual spectrum of the noise as estimated from the data. The discussion that follows is centered on various aspects conc erning the practical application of the matched filter as well as the loss of performance due both to uncertainties on the parameters used f or building the filter and to various discretization effects, both in the time and frequency domains. Finally, rye consider some experimenta l results obtained by applying the matched filter to the data of the E xplorer detector, also providing a comparison with what we obtained by applying an optimum filter to data processed by lock-in amplifiers, s ampled at lower speed.