Comparison of precipitable water over Ghana
using GPS signals and reanalysis products

Acheampong, Akwasi A.; Fosu, Collins; Amekudzi, Leonard K.; Kaas, Eigil

doi:10.1515/jogs-2015-0016

Cited by 7 publications

(3 citation statements)

References 5 publications

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“…Przykładem takiego oprogramowania jest aplikacja nawigacja gLAB stosowana do pozycjonowania satelitarnego GNSS w trybie post-processing [16]. Program gLAB (GNSS-Lab Tool) jest powszechnie stosowany w pozycjonowaniu statycznym GNSS [10], pozycjonowaniu kinematycznym GNSS [12], monitoringu stanu troposfery [1] itp. Program gLAB ma szero-kie spektrum zastosowania badawczego, w tym także może być wykorzystywany w nawigacji lotniczej do odtworzenia pozycji statku powietrznego.…”

Section: Wprowadzenieunclassified

The Impact of IGS Precise Products in Aircraft Positioning in Air Navigation

Krasuski¹

2018

PAR

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Streszczenie: W pracy przedstawiono rezultaty pozycjonowania statku powietrznego Cessna 172 w nawigacji lotniczej z użyciem techniki pomiarowej PPP. Eksperyment badawczy przeprowadzono z użyciem nieróżnicowych obserwacji GPS zarejestrowanych przez odbiornik pokładowy Topcon HiperPro. Pozycja samolotu Cessna 172 została odtworzona w programie gLAB. W artykule opisano pełny algorytm dla techniki pomiarowej PPP oraz przedstawiono konfigurację modułu PPP w programie gLAB. W obliczeniach wykorzystano precyzyjne produkty służby IGS, tzn. dane efemerydalne i zegary satelitów GPS. W obliczeniach uzyskano wartości błędów średnich wyznaczenia pozycji samolotu Cessna 172 na poziomie niższym niż 0,10 m.

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Section: Wprowadzenieunclassified

The Impact of IGS Precise Products in Aircraft Positioning in Air Navigation

Krasuski¹

2018

PAR

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“…Lack of meteorological sensors attached to NIGNET and the poor resolution of NCEP/DOE was attributed to the weak correlation. In Ghana, Acheampong et al (2015) found a correlation of more than 60% when PWV from GNSS was compared with that from the NCEP/DOE Reanalysis II. The study of Isioye et al (2017) capitalized on the NIGNET to study spatio-temporal variability of PWV.…”

Section: Introductionmentioning

confidence: 97%

An Appraisal of the Ecmwf Reanalysis5 (Era5) Model in Estimating and Monitoring Atmospheric Water Vapour Variability Over Nigeria

Bawa

Isioye

Moses

et al. 2022

Geodesy and Cartography

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This study research the performance of the ERA5 reanalysis model in estimating and monitoring the variability of atmospheric water vapour content over Nigeria. The ERA5 is a fifth-generation reanalysis model recently released by the European Centre for Medium-Range Weather Forecasts (ECMWF). The ERA5 model comes with excitingly high spatial and temporal resolution when compared to earlier models like the ERA-Interim and ERA-40. However, like the previous models, the ERA5 comes with numerous modelling uncertainties arising from data fusion methods and observation schemes, which often affects its performance at the different regions of the Earth. In this study, ERA5 precipitable water vapour (PWV) was validated with GNSS PWV from permanent GNSS stations in Nigeria NIGNET for the period of 2012–2013. The performance of ERA5 was investigated at sub-daily, diurnal, and seasonal scales in relation to KöppenGeiger climate classification using standard statistical metrics (namely, coefficient of correlation (r), Root mean square error (RMSE), Reliability index (RI), Mean absolute errors (MAE) and mean bias). The r, RI, RMSE, MAE and mean bias values at sub-daily, diurnal and seasonal scales were computed as, (0.8670, 0.882, 0.979), (3.697 mm, 3.400 mm, 7.014 mm), (1.015, 1.019, 1.008), (2.769 mm, 2.706 mm, 1.939 mm) and (0.826 mm, 2.033 mm, 1.739 mm), respectively. The results indicate the strongest performance of ERA5 at seasonal scale with more than 95% agreement. The pattern of variability of ERA5 within the different climate zones of Nigeria showed good consistency with GNSS PWV and Köppen-Geiger climate classification. The study recommended the use of ERA5 in the retrieval of historic PWV records and near real-time GNSS applications.

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“…e results showed that GNSS-PWV provides a useful source of humidity information which can be utilised to improve the water cycle in numeric weather models (NWMs) for various applications in Nigeria. Furthermore, as means of enhancing PWV retrieval from GNSS ground-based receivers in West Africa, Isioye et al [28] [29] comparatively studied PWV estimation using GNSS observations in Ghana and datasets from ERA-Interim and NCEP reanalysis. e study demonstrated that PWV can be obtained with high precision from GNSS signals in Ghana.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Zenith Tropospheric Delay Derived from Ray-Traced VMF3 Product over the West African Region Using GNSS Observations

Osah

Acheampong

Fosu

et al. 2021

Advances in Meteorology

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The growing demand for Global Navigation Satellite System (GNSS) technology has necessitated the establishment of a vast and ever-growing network of International GNSS Service (IGS) tracking stations worldwide. The IGS provides highly accurate and highly reliable daily time-series Zenith Tropospheric Delay (ZTD) products using data from the member sites towards the use of GNSS for precise geodetic, climatological, and meteorological applications. However, if for reasons like poor internet connectivity, equipment failure, and power outages, the IGS station is inaccessible or malfunctioning, and gaps are created in the data archive resulting in degrading the quality of the ZTD and precipitable water vapour (PWV) estimation. To address this challenge as a means of providing an alternative data source to improve the continuous availability of ZTD data and as a backup data in the event that the IGS site data are missing or unavailable in West Africa, this paper compares the sitewise operational Vienna Mapping Functions 3 (VMF3) ZTD product with the IGS final ZTD product over five IGS stations in West Africa. Eight different statistical evaluation metrics, such as the mean bias (MB), mean absolute error (MAE), root mean squared error (RMSE), Pearson correlation coefficient (r), coefficient of determination (r2), refined index of agreement (IAr), Nash–Sutcliffe coefficient of efficiency (NSE), and the fraction of prediction within a factor of two (FAC2), are employed to determine the degree of agreement between the VMF3 and IGS tropospheric products. The results show that the VMF3-ZTD product performed excellently and matches very well with the IGS final ZTD product with an average MB, MAE, RMSE, r, r2, NSE, IAr, and FAC2 of 0.38 cm, 0.87 cm, 1.11 cm, 0.988, 0.976, 0.967, 0.992, and 1.00 (100%), respectively. This result is an indication that the VMF3-ZTD product is accurate enough to be used as an alternative source of ZTD data to augment the IGS final ZTD product for positioning and meteorological applications in West Africa.

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Comparison of precipitable water over Ghana using GPS signals and reanalysis products

Cited by 7 publications

References 5 publications

The Impact of IGS Precise Products in Aircraft Positioning in Air Navigation

The Impact of IGS Precise Products in Aircraft Positioning in Air Navigation

An Appraisal of the Ecmwf Reanalysis5 (Era5) Model in Estimating and Monitoring Atmospheric Water Vapour Variability Over Nigeria

Evaluation of Zenith Tropospheric Delay Derived from Ray-Traced VMF3 Product over the West African Region Using GNSS Observations

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