All-sky and wide parameter space searches for continuous gravitational waves are generally template-matching schemes which test a bank of signal waveforms against data from a gravitational wave detector. Such searches can offer optimal sensitivity for a given computing cost and signal model, but are highly-tuned to specific signal types and are computationally expensive, even for semi-coherent searches. We have developed a search method based on the well-known Viterbi algorithm which is model-agnostic and has a computational cost several orders of magnitude lower than template methods, with a modest reduction in sensitivity. In particular, this method can search for signals which have an unknown frequency evolution. We test the algorithm on three simulated and real data sets: gapless Gaussian noise, Gaussian noise with gaps and real data from the final run of initial LIGO (S6). We show that at 95% efficiency, with a 1% false alarm rate, the algorithm has a depth sensitivity of ∼33, 10 and 13 ,Hz−1/2 with corresponding SNRs of ∼60, 72 and 74 in these datasets. we discuss the use of this algorithm for detecting a wide range of quasi-monochromatic gravitational wave signals and instrumental lines.
@article{arxiv.1903.12614,
title = {SOAP: A generalised application of the Viterbi algorithm to searches for continuous gravitational-wave signals},
author = {Joe Bayley and Graham Woan and Chris Messenger},
journal= {arXiv preprint arXiv:1903.12614},
year = {2019}
}