2017/11/22 by Paul S. Ray, Ray, Paul S., K. S. Wood +3 · 1 citation
Engineering · Physics and Astronomy · #FOS: Physical sciences #Geophysics and Sensor Technology #High Energy Astrophysical Phenomena (astro-ph.HE) #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Pulsars and Gravitational Waves Research #Superconducting Materials and Applications
paper · pdf · doi:10.48550/arxiv.1711.08507
openalex publication_date 2017/11/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology demonstration enhancement to the Neutron Star Interior Composition Explorer (NICER) mission, which is scheduled to launch in 2017 and will be hosted as an externally attached payload on the International Space Station (ISS). During NICER's 18-month baseline science mission to understand ultra-dense matter through observations of neutron stars in the soft X-ray band, SEXTANT will, for the first-time, demonstrate real-time, on-board X-ray pulsar navigation. Using NICER/SEXTANT as an example, we describe the factors that determine the measurement errors on pulse times of arrival, including source and background count rates, and pulse profile shapes. We then describe properties of the SEXTANT navigation pulsar catalog and prospects for growing it once NICER launches. Finally, we describe the factors affecting the prediction of pulse arrival times in advance, including variable interstellar propagation effect and red timing noise. Together, all of these factors determine how well a particular realization of an X-ray pulsar-based navigation system will perform.