Results 141 to 150 of about 525 (158)

Global empirical model for mapping zenith wet delays onto precipitable water

Journal of Geodesy, 2013
We can map zenith wet delays onto precipitable water with a conversion factor, but in order to calculate the exact conversion factor, we must precisely calculate its key variable $$T_\mathrm{m}$$ . Yao et al. (J Geod 86:1125–1135, 2012.
Yi Bin Yao, Bao Zhang, Shun Qiang Yue, Chao Qian Xu, Wen Fei Peng   +4 more
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Prediction of zenith wet delays using artificial neural networks for precise point positioning

2023
Permanent GNSS stations provide invaluable observations to estimate the zenith tropospheric delays in near realtime. However, the prediction of zenith wet delays is still a challenge due to the high spatial and temporal variation of atmospheric water vapour. Recently a near realtime GNSS data processing system has been set up at the Budapest University
Laky, P., Acs, A., Rozsa, S.
openaire   +2 more sources

SPACE TO EARTH TECHNIQUES: SOME CONSIDERATIONS ON THE ZENITH WET PATH DELAY PARAMETERS

Survey Review, 1993
AbstractSpace to Earth techniques have often limited accuracy due to various atmospheric effects. The most spatial of these is the wet path delay which in general is the most difficult to predict using a model based on surface weather observations. In this report we study wet delay parameters assuming that the water vapour pressure is exponentially ...
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Estimation of Missing GPS Precipitable Water Vapor Data by Zenith Wet Delay and Meteorological Data

Advanced Materials Research, 2014
This article presents a statistical correlation between GPS precipitable water vapor and meteorological data, i.e., surface temperature, air pressure, relative humidity, dew point temperature, and water vapor pressure by using linear regression. The data, recorded over a 4-year period, was used as an estimation of missing GPS precipitable water vapor ...
Prawit Uang-Aree, Sununtha Kingpaiboon, Kulyakorn Khuanmar   +2 more
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Tibetan zenith wet delay model with refined vertical correction

Journal of Geodesy, 2023
Chaoqian Xu, Chen Liu, Yibin Yao, Qin Wang, Xiaoqing Wang   +4 more
openaire   +1 more source

Monitoring the TOPEX and Jason-1 Microwave Radiometers with GPS and VLBI Wet Zenith Path Delays

Marine Geodesy, 2004
Monitoring of altimeter microwave radiometer measurements is necessary in order to identify radiometer drifts or offsets that if uncorrected will introduce systematic errors into ocean height measurements. To examine TOPEX Microwave Radiometer (TMR) and Jason-1 Microwave Radiometer (JMR) behavior, we have used coincident wet zenith delay estimates from
D. S. MACMILLAN, B. D. BECKLEY, P. FANG
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Improved Parameter Estimation of Zenith Wet Delays Using an Inequality Constrained Least Squares Method

2015
The path of signals from space geodetic techniques, such as Very Long Baseline Interferometry (VLBI) or Global Navigation Satellite Systems (GNSS), is affected by refractivity variations in the neutral atmosphere. This tropospheric delay, which represents a major contribution to the error budget of space geodetic observations, is generally considered ...
Sebastian Halsig, Lutz Roese-Koerner, Thomas Artz, Axel Nothnagel, Wolf-Dieter Schuh   +4 more
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A refined tropospheric zenith wet delay model for GNSS applications over the Tibetan Plateau

Significant spatial heterogeneity of tropospheric water vapor over the Tibetan Plateau, particularly along the vertical dimension, presents a major challenge to traditional tropospheric wet delay models used in GNSS applications across large height ranges.
Chen Liu, Junli Wu, Xiaoqing Wang, Chaoqian Xu   +3 more
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Investigating Effects of Usage of Zenith Tropospheric Wet Delay Models on Positioning Accuracy

2017
Global Navigation Satellite System (GNSS) is actively being used for various purposes such asengineering studies, deformation measurements, meteorological predictions, navigation. The methodwould be used depends on work to be applied. Relative and absolute positioning techniques are thetwo main methods that distinguish positioning with GNSS as the ...
Soycan, Metin, Gürtürk, Mert, Erdem, Çağan   +2 more
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GNSS-based Troposphere Zenith Wet Delay Estimation Comparison with Microwave Radiometer At Cabauw

2009
At the Radio Science laboratory of the University of Bologna in Forlì a dedicated GNSS data analysis software (S/W) code was developed as part of the radio science activities connected to the future ESA BepiColombo and ExoMars missions. After a short description of the algorithms used in the S/W code developed, the paper will reports the results of an
GRAZIANI, ALBERTO, R. Bertacin, TORTORA, PAOLO, A. Martellucci, S. De Haan   +4 more
openaire   +1 more source