Pulsars with their periodic pulses and known positions are ideal beacons for navigation. The challenge, however,is the detection of the very weak pulsar signals that are submerged in noise. Radio based approaches allow the use ofadvanced techniques and methods for the detection and acquisition of such weak signals. In this paper, an effectivesignal acquisition method based on epoch folding and matched filtering is proposed that can enable pulsar navigationon spacecraft.Traditionally astronomers use an epoch folding algorithm to search for new pulsars which is a very time andprocessing power-consuming approach. Since a pulsar navigation system uses signals from known pulsars, advancedalgorithms can reduce the time and processing power required for pulsar detection. Applying optimization methodson folding algorithms could lead to an increase in detection speed, however, it is not practical when taking all knownsignal parameters into account. In this paper a new approach is proposed to reduce the time and processing powerfurther, considering a-priori knowledge such as pulse shape.This approach is based on the concept of matched filtering. Matched filtering is the basic tool for extractingknown wavelets from a signal that has been contaminated by noise. A matched filter is obtained by correlating theobservation with a template of a known signal, to detect its presence. Such a matched filter is the optimal linear filterfor maximizing the signal-to-noise-ratio (SNR) in the presence of additive stochastic noise.After a description of the underlying theory, simulations shows that by using this method, significant increases indetection speeds are possible.
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