干旱区生态环境知识资源中心(Arid): Variability and accuracy of Zenith Total Delay over the East African tropical region

Arid

DOI	10.1016/j.asr.2019.05.027
	Variability and accuracy of Zenith Total Delay over the East African tropical region
	Ssenyunzi, Richard Cliffe 1,2; Oruru, Bosco 1; D’ujanga, Florence Mutonyi 1; Realini, Eugenio 3; Barindelli, Stefano 4; Tagliaferro, Giulio 3; van de Giesen, Nick 5
通讯作者	Ssenyunzi, Richard Cliffe
来源期刊	ADVANCES IN SPACE RESEARCH
ISSN	0273-1177
EISSN	1879-1948
出版年	2019
卷号	64 期号:4 页码:900-920
英文摘要	The Global Navigation Satellite System (GNSS) can be used to derive accurately the Zenith Tropospheric Delay (ZTD) under all-weather conditions. The derived ZTDs play a vital role in climate studies, weather forecasting and are operationally assimilated into numerical weather prediction models. In this study, variations and statistical analysis of GNSS-derived ZTD over the East African tropical region are analysed. The data is collected from 13 geodetic permanent stations for the period of 4 years from 2013 to 2016. The 13 stations consist of 5 International GNSS Service (IGS) stations plus 8 stations as follows: 4 Africa Array stations and 4 Malawi Rifting stations from Uganda, Kenya, Tanzania and Rwanda. The ZTD time series were processed using goGPS software version 1.0 betal, a MATLAB based GNSS processing software, originally developed for kinematic applications but recently re-engineered for quasi static applications. The annual variation of the ZTD time series was investigated using Lomb Scargle periodograms. The semi-annual frequency has the dominant power in subregion 1 (latitudes 4 degrees S and 4 degrees N) and the annual frequency has the dominant power in subregion 2 (latitudes 12 degrees S to 4 degrees S). The highest ZTD estimates occur during the rainy seasons, at all stations, and the lowest estimates occur during the dry seasons. The results also show that the ZTD estimates are largest at stations located at low elevation (regions close to the Indian Ocean). The derived ZTDs are compared to the values derived from the GIPSY-OASIS via Jet Propulsion Laboratory (JPL) online Automatic Precise Positioning Service (APPS) and the Unified Environmental Modelling System (UEMS) numerical weather prediction (NWP) model. The comparison of goGPS and APPS ZTD at the 13 stations shows an overall average bias, Root Mean Square (RMS) and standard deviation (stdev) of -0.9 mm, 3.2 mm and 3.0 mm respectively, with correlation coefficients ranging from 0.974 to 0.999. The comparison of goGPS ZTD against UEMS NWP ZTD at 8 selected stations shows average bias, RMS and stdev of -12.4 mm, 22.0 mm and 17.6 mm respectively, with correlation coefficients ranging from 0.802 to 0.974. The agreement between the GPS ZTD and the NWP ZTD indicates that goGPS ZTD can be assimilated into NWP models in the East African region. (C) 2019 COSPAR. Published by Elsevier Ltd. All rights reserved.
英文关键词	Precise point positioning Zenith tropospheric delay GNSS goGPS UEMS-NWP
类型	Article
语种	英语
国家	Uganda ; Italy ; Netherlands
开放获取类型	Green Published
收录类别	SCI-E
WOS记录号	WOS:000474677800008
WOS关键词	PRECIPITABLE WATER-VAPOR ; NWP MODEL ; TROPOSPHERIC DELAYS ; MAPPING FUNCTIONS ; GPS DATA ; PREDICTION ; RADIOSONDE ; PERFORMANCE ; METEOROLOGY ; RAINFALL
WOS类目	Engineering, Aerospace ; Astronomy & Astrophysics ; Geosciences, Multidisciplinary ; Meteorology & Atmospheric Sciences
WOS研究方向	Engineering ; Astronomy & Astrophysics ; Geology ; Meteorology & Atmospheric Sciences
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/213887
作者单位	1.Makerere Univ, Dept Phys, POB 7062, Kampala, Uganda; 2.Busitema Univ, Dept Phys, POB 236, Tororo, Uganda; 3.Geomat Res & Dev Srl, Via Cavour 2, I-22074 Lomazzo, Italy; 4.Politecn Milan, Dept Civil & Environm Engn, Pzza Leonardo da Vinci 32, I-20133 Milan, Italy; 5.Civil Engn & Geosci TU Delft, Water Management, POB 5048, NL-2600 GA Delft, Netherlands
推荐引用方式 GB/T 7714	Ssenyunzi, Richard Cliffe,Oruru, Bosco,D’ujanga, Florence Mutonyi,et al. Variability and accuracy of Zenith Total Delay over the East African tropical region[J],2019,64(4):900-920.
APA	Ssenyunzi, Richard Cliffe.,Oruru, Bosco.,D’ujanga, Florence Mutonyi.,Realini, Eugenio.,Barindelli, Stefano.,...&van de Giesen, Nick.(2019).Variability and accuracy of Zenith Total Delay over the East African tropical region.ADVANCES IN SPACE RESEARCH,64(4),900-920.
MLA	Ssenyunzi, Richard Cliffe,et al."Variability and accuracy of Zenith Total Delay over the East African tropical region".ADVANCES IN SPACE RESEARCH 64.4(2019):900-920.