Related papers: Time Assignment System and Its Performance aboard …
This paper presents an observing methodology for calibrated measurements of radio interference levels and compare these with threshold interference limits that have been established for interference entering the bands allocated to the Radio…
The Space Interferometry Mission (SIM), with its launch date planned for 2005, has as its goal astrometry with ~ 1 micro-arcsecond accuracy for stars as faint as 20th mag. If the SIM lives to expectations it can be used to measure…
Mission-critical system, such as satellite systems, healthcare systems, and nuclear power plant control systems, undergo rigorous testing to ensure they meet specific operational requirements throughout their operation. This includes…
The problem of determination of the orbital velocity of an astrometric satellite from its own observational data is studied. It is well known that data processing of microarcsecond-level astrometric observations imposes very stringent…
Precise (sub-meter level) real-time navigation using a space-capable single-frequency global positioning system (GPS) receiver and ultra-rapid (real-time) ephemerides from the international global navigation satellite systems service is…
Precision timing is the key ingredient of ongoing pulsar-based gravitational wave searches and tests of general relativity using binary pulsars. The conventional approach to timing explicitly assumes that the radio emitting region is…
Ultrahigh accuracy time synchronization technique based on the optical frequency comb and the GHZ radio frequency spiral scanning deflector is suggested to install on the Moon during the ARTEMIS mission. The comparison with the parameters…
We investigate the performance of the upcoming ACES (Atomic Clock Ensemble in Space) space mission in terms of its primary scientific objective, the test of the gravitational redshift. Whilst the ultimate performance of that test is…
Space-borne gravitational wave detection will open the observation window in the 0.1 mHz$-$1 Hz bandwidth, playing a crucial role in the development of cosmology and physics. Precise clock synchronization among satellites is essential for…
Timing and carrier synchronization is a fundamental requirement for any wireless communication system to work properly. Timing synchronization is the process by which a receiver node determines the correct instants of time at which to…
The Global Positioning System (GPS) is a U.S. space-based radionavigation system that provides reliable positioning, navigation, and timing services to civilian users on a continuous worldwide basis -- freely available to all. GPS provides…
By the precise timing of the low amplitude (0.005 - 0.02 magnitude) transits of exoplanets around their parent star it should be possible to infer the presence of other planetary bodies in the system down to Earth-like masses. We describe…
Modern satellite based experiments are often very complex real-time systems, composed by flight and ground segments, that have challenging resource related constraints, in terms of size, weight, power, requirements for real-time response,…
The Space Interferometry Mission (SIM) will make precise astrometric measurements that can be used to detect planets around nearby stars. Since observational time will be extremely valuable, it is important to consider how the choice of the…
(Abridged) The probability of detecting additional companions is essentially unchanged with respect to the single-planet configurations, but after fitting and subtraction of orbits with astrometric signal-to-noise ratio $\alpha/\sigma_d\to…
The radio as well as the high energy emission mechanism in pulsars is yet not understood properly. A multi-wavelength study is likely to help in better understanding of such processes. The first Indian space-based observatory, ASTROSAT, has…
Accurate and stable spacecraft pointing is a requirement of many astronomical observations. Pointing particularly challenges nanosatellites because of an unfavorable surface area to mass ratio and proportionally large volume required for…
The Helioseismic and Magnetic Imager (HMI) instrument is a major component of NASA's Solar Dynamics Observatory (SDO) spacecraft. Since beginning normal science operations on 1 May 2010, HMI has operated with remarkable continuity, e.g.…
Astrometry provides the foundation for astrophysics. Accurate positions are required for the association of sources detected at different times or wavelengths, and distances are essential to estimate the size, luminosity, mass, and ages of…
Vehicular Networks are one of the enabling technologies for cooperative Intelligent Transportation Systems. For accurate and precise time synchronization in vehicular networks, Global Navigation Satellite System (GNSS) is getting increasing…