Results 91 to 100 of about 5,434 (212)

The VMD-Informer-BiLSTM-EAA Hybrid Model for Predicting Zenith Tropospheric Delay

Remote Sensing
Zenith Tropospheric Delay (ZTD) is a significant source of atmospheric error in the Global Navigation Satellite System (GNSS). Developing a high-accuracy ZTD prediction model is essential for both GNSS positioning and GNSS meteorology.
Zhengdao Yuan, Xu Lin, Yashi Xu, Ruiting Dai, Cong Yang, Lunwei Zhao, Yakun Han   +6 more
doaj   +1 more source

An improved global pressure and zenith wet delay model with optimized vertical correction considering the spatiotemporal variability in multiple height-scale factors [PDF]

Geoscientific Model Development
Atmospheric pressure and zenith wet delay (ZWD) are essential for global navigation satellite system (GNSS) tropospheric correction and precipitable water vapor (PWV) retrieval. As the development progresses of real-time GNSS kinematic technology, moving
C. Jiang, C. Jiang, C. Jiang, X. Gao, H. Zhu, S. Wang, S. Liu, S. Chen, G. Liu   +8 more
doaj   +1 more source

Influence of ionospheric perturbations in GPS time and frequency transfer [PDF]

, 2009
The stability of GPS time and frequency transfer is limited by the fact that GPS signals travel through the ionosphere. In high precision geodetic time transfer (i.e. based on precise modeling of code and carrier phase GPS data), the so-called ionosphere-
Bassiri, Berghmans, Brunner, Carine Bruyninx, Hernandez-Pajares, Hoque, Kouba, Laurence Wauters, Lyard, Nicolas Bergeot, Niell, Pascale Defraigne, Quentin Baire, Sophie Pireaux, Wu   +14 more
core   +1 more source

Deep space tracking in local reference frames [PDF]

A self-calibrating deep space tracking technique is described which can potentially produce two nanoradian angular spacecraft determinations. The technique uses very long base interferometric observations of a spacecraft and several radio sources.
Treuhaft, R. N.
core   +1 more source

A demonstration of high precision GPS orbit determination for geodetic applications [PDF]

High precision orbit determination of Global Positioning System (GPS) satellites is a key requirement for GPS-based precise geodetic measurements and precise low-earth orbiter tracking, currently under study at JPL.
Border, J. S., Lichten, S. M.
core   +1 more source

The Numerical Simulation of the Atmosphere Delays Impact on Radar Measurement in Aviation

Communications, 2019
The article presents numerical simulations with regard to determining the impact of the ionospheric and tropospheric delays on a radar-aircraft slant distance measurement.
Kamil Krasuski, Artur Gos
doaj   +1 more source

Empirical model of correction for zenith tropospheric delay

Journal of Measurement Science and Instrumentation, 2014
The paper considers the possibility of correction of zenith tropospheric delays,and calculates it with the standard model,which takes into account the values of the refractive index of the troposphere at the time of measurement. Based on the experimental
V F Kravchenko, V I Lutsenko, I V Lutsenko, D O Popov, A G Laush, V N Gudkov   +5 more
doaj  

From Reference Frames to Relativistic Experiments: Absolute and Relative Radio Astrometry

, 2004
Reference systems and frames are crucial for high precision absolute astrometric work, and their foundations must be well-defined. The current frame, the International Celestial Reference Frame, will be discussed: its history, the use of the group delay ...
Fomalont, E. B.
core   +2 more sources

Characterization of site-specific GPS errors using a short-baseline network of braced monuments at Yucca Mountain, southern Nevada [PDF]

, 2009
We use a short-baseline network of braced monuments to investigate site-specific GPS effects. The network has baseline lengths of ∼10, 100, and 1000 m. Baseline time series have root mean square (RMS) residuals, about a model for the seasonal cycle, of 0.
Davis, James L., Elósegui, Pedro, Hill, Emma M., Malikowski, Eric, Niemi, Nathan A., Wernicke, Brian P.   +5 more
core   +2 more sources

A New Global ZTD Forecast Model Based on Improved LSTM Neural Network

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Zenith tropospheric delay (ZTD), consisting of zenith hydrostatic delay (ZHD) and zenith wet delay (ZWD), is a significant contributor to errors in precise positioning using the global navigation satellite system (GNSS) precise point positioning (PPP ...
Lin He, Yibin Yao, Chaoqian Xu, Zhang Huan, Feifei Tang, Changquan Ji, Zhuoya Liu, Wentan Wu   +7 more
doaj   +1 more source