this paper where we are interested in estimating the parameters and also the errors made in such a estimation. Errors in the estimation arise because the noise contaminates the data.

The noise in ground based laser interferometric detectors will have, in general, both a Gaussian and a non-Gaussian component. The main sources for the Gaussian component are the shot noise due to photon counting, the thermal noise in the mirror suspensions alongwith the mirror itself and seismic noise. The non-Gaussian component can be contributed by numerous sources like sudden strain releases in the mirror suspension wires or even if lightning strikes. It should be possible to remove most of the non-Gaussian component by using environmental monitors and looking for coincidence among detectors located at widely separated sites. It is, therefore, assumed usually that the detector noise will be a Gaussian random process. Over a time scale of hours, it can also be assumed to be stationary.

The power spectral density of the Gaussian noise component rises very steeply towards the low frequency end due to seismic effects. At the high frequency end it is dominated by photon shot noise which leads to a rise towards higher frequencies. Thus the data 