Simulation And Bispectral De-noising Of Pulsar Signal

As a hot spot on the research of space navigation in recent years, X-ray Pulsar-based Navigation (XPNAV) can offer abundant navigation information, such as position, velocity, attitude and time etc. for the spacecrafts in near-Earth orbit, deep space and interplanetary space. In order to solve the problems of the absorption of X-ray photons by the Earth’s atmosphere and the huge costs of space flight experiments, an XPNAV simulation system can be founded on the earth to evaluate the feasibility of the scheme and the validity of navigation algorithms.For XPNAV simulation system, a signal simulation method based on a0-1distribution model of arrival photons which are radiated by X-ray pulsar is proposed in this article. Experiments show that with a short observation period, the integrated pulse profile which is simulated by this model has a smaller average phase difference than the one produced by non-homogeneous Poisson process model. Combining the bispectrum of signals and the methods used in image de-noising, a new signal de-noising method which is based on Non-local Means (NL-means) algorithm is presented in this paper. This method can be used to improve the signal-to-noise ratio of the integrated pulse profile built in a short observation period. Experiments show that the efficacy of this method is better than the one that is dependent upon α-trimmed filter.