Results 161 to 170 of about 12,906 (196)

Impact of GPS antenna phase center models on zenith wet delay and tropospheric gradients

GPS Solutions, 2018
Today Global Navigation Satellite Systems (GNSS) tropospheric products, such as zenith total delays (ZTD) and zenith wet delays (ZWD), are widely used as complementary data sets in numerical weather prediction models. In particular, the wet delays are treated as unknown parameters in GNSS processing and are estimated with other parameters such as ...
Yohannes Getachew Ejigu, Addisu Hunegnaw, Kibrom Ebuy Abraha, Felix Norman Teferle   +3 more
openaire   +1 more source

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
openaire   +1 more source

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 ...
openaire   +1 more source

The Validation of WET Zenith Delay of Ground GPS Stations Based on Jason-2 AMR

IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium, 2018
The wet zenith delay(WZD) can be estimated by ground GPS stations as well as satellite altimeter. The Jason-2 altimeter has been an operational satellite, which provides the sea surface height with several centimeters, and have the high accuracy of measuring the WZD using a Microwave Radiometer (AMR).
Zhai Wanlin, Zhu Jianhua, Chen Chuntao, Wang He, Huang Xiaoqi, Yan Longhao   +5 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
openaire   +1 more source

Forecasting rainfall events based on zenith wet delay time series utilizing eXtreme gradient boosting (XGBoost)

Advances in Space Research
Accurate rainfall prediction is vital for mitigating flood and storm disasters as well as for planning agricultural activities and water resources management. GNSS observations enable the estimation of atmospheric water vapor content through the Zenith Wet Delay (ZWD) value, where previous studies indicate a strong correlation between the ZWD-derived ...
Dehvari, Masood, Farzaneh, Saeed, Forootan, Ehsan; id_orcid 0000-0003-3055-041X   +2 more
openaire   +1 more source

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
openaire   +1 more source

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

Analysis and Estimation of Zenith Wet Delay and Zenith Tropospheric Total Delay at Earth’s different Geographical Areas

2021 Seventh International Conference on Aerospace Science and Engineering (ICASE), 2021
openaire   +1 more source

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