Pulsar search using data compression with the Garching gravitational wave detector

We describe briefly the standard problems associated with the detection of a periodic signal of astrophysical origin. We present a method for data compression when the bandwidth of the expected signal is much smaller than the detector bandwidth. The reduced data set can be corrected for the Doppler shift due to Earth's orbital and rotational motion even when the expected signal is close to the Nyquist frequency of the original data rate. Standard matched filtering techniques and Fourier transform processing can also be implemented on the compressed data stream. We applied this procedure to 100 hours of data taken with the Garching gravitational wave prototype detector. The results of this test reveal that the amplitude statistics of our prototype in the frequency domain follow closely the expected Rayleigh distribution over all 100 h. This analysis puts a constraint of 9 × ${10}^{-21\mathrm{}}$ on possible gravitational wave strains produced by periodic sources in SN 1987A.