Results 121 to 130 of about 8,653 (226)

Updated Spin Ephemeris for the Cataclysmic Variable EX Hydrae [PDF]

arXiv, 2009
Historical optical data are combined with more recent optical, extreme ultraviolet, and X-ray data to update the spin ephemeris of the cataclysmic variable EX Hya.
arxiv  

VEGA Pathfinder navigation for Giotto Halley encounter [PDF]

Results of the VEGA Pathfinder concept which was used to successfully target the European Space Agnecy's Giotto spacecraft to a 600 km encounter with the comet Halley are presented.
Ellis, J., Mcelrath, T. P.
core   +1 more source

Broadcast Product: Shape-aligned Element-wise Multiplication and Beyond [PDF]

arXiv
We propose a new operator defined between two tensors, the broadcast product. The broadcast product calculates the Hadamard product after duplicating elements to align the shapes of the two tensors. Complex tensor operations in libraries like \texttt{numpy} can be succinctly represented as mathematical expressions using the broadcast product.
arxiv  

A 116 Year Record of Mass Transfer in R Arae [PDF]

Reed, P. A., 2011, Information Bulletin on Variable Stars, 5975, 2011
This is a period study of the bright interacting southern eclipsing binary star R Arae. New photometric data are combined with archival data to determine R Ara's average mass transfer rate over the past 116 years through the analysis of the resulting ephemeris curve. An updated ephemeris is given.
arxiv  

Application of GPS tracking techniques to orbit determination for TDRS [PDF]

In this paper, we evaluate two fundamentally different approaches to TDRS orbit determination utilizing Global Positioning System (GPS) technology and GPS-related techniques. In the first, a GPS flight receiver is deployed on the TDRSS spacecraft.
Haines, B. J., Lichten, S. M., Malla, R. P., Wu, S. C.   +3 more
core   +1 more source

Hybrid Digital-Analog Codes for Source-Channel Broadcast of Gaussian Sources over Gaussian Channels [PDF]

arXiv, 2011
The problem of broadcasting a parallel Gaussian source over an additive white Gaussian noise broadcast channel under the mean-squared error distortion criterion is studied. A hybrid digital-analog coding strategy which combines source coding with side information, channel coding with side information, layered source coding, and superposition broadcast ...
arxiv  

SISRE of BDS-3 MEO: Evolution as Well as Comparison between D1 and B-CNAV (B-CNAV1, B-CNAV2) Navigation Messages

Remote Sensing
The signal-in-space range error (SISRE) has a direct impact on the performance of global navigation satellite systems (GNSSs). It is an important indicator of navigation satellite space server performance.
Zhenghua Dong, Songlin Zhang
doaj   +1 more source

Simulation and analysis of differential global positioning system for civil helicopter operations [PDF]

A Differential Global Positioning System (DGPS) computer simulation was developed, to provide a versatile tool for assessing DGPS referenced civil helicopter navigation.
Cabak, A. R., Denaro, R. P.
core   +1 more source

The Implementation of Precise Point Positioning (PPP): A Comprehensive Review. [PDF]

Sensors (Basel), 2023
Elsheikh M, Iqbal U, Noureldin A, Korenberg M.   +3 more
europepmc   +1 more source

Prediction and ephemeris fitting of LEO navigation satellites orbits computed at the antenna phase center [PDF]

Nowadays, Low Earth Orbit (LEO) satellites are proposed to augment the Positioning, Navigation and Timing (PNT) service of the GNSS satellites by directly transmitting navigation signals. In such cases, the users eventually need the orbits at the Antenna
El-Mowafy, Ahmed, Su, H., Wang, K., Yang, X.   +3 more
core   +1 more source