Mathematical models are developed to characterize the X-ray pulsar signals, and the pulse
phase estimation problem is addressed. The Cramér-Rao lower bound for estimation of the …

How the relative position between two spacecraft can be estimated utilizing signals emitted
from X-ray pulsars is explained. The mathematical models of X-ray pulsar signals are …

Navigation in Space by X-ray Pulsars will consist of two parts. One is on modeling of X-ray
pulsar signals. The second part explains how X-ray pulsar signals can be used to solve the …

In order to reduce the composite impacts of the systematic biases in the X-ray pulsar-based
navigation system, an innovative navigation method is proposed. The proposed method …

This paper suggests utilizing X-ray pulsars for relative navigation between two spacecraft in
deep space. Mathematical models describing X-ray pulsar signals are presented. The pulse …

The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a NASA
funded technology-demonstration. SEXTANT will, for the first time, demonstrate real-time, on …

In this paper, the arrival times of X-ray photons from variable celestial sources, measured by
an X-ray detector onboard a spacecraft, are modeled as a non-homogeneous Poisson …

An important part of a rapid response to spacecraft faults is obtaining information efficiently
and accurately determining the cause of the faults. The cause may originate from any stage …

We demonstrate how observations of pulsars can be used to help navigate a spacecraft
travelling in the solar system. We make use of archival observations of millisecond pulsars …

The performance of the navigation system during the Mars final approach phase determines
the initial accuracy of Mars entry phase, which is critical for a pin-point landing. An X-ray …