Assessing the Quality of Data from Continuously Operating Reference Stations in Ghana

  • Dr. Osman Mohammed Abukari Survey and Mapping Division, Lands Commission, Accra, Ghana
  • Dr. Akwasi Afrifa Acheampong Geomatic Engineering Department of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
  • Dr. Samuel Osah Geomatic Engineering Department of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
  • Rev. (Prof.) John Ayer Geomatic Engineering Department of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
Keywords: GNSS, CORS, Multipath, Cycle Slip, Data Completeness

Abstract

Assessing the Quality of Data from Continuously Operating Reference Stations In Ghana Since 2019, Ghana has witnessed the establishment of new Continuously Operating Reference Stations (CORS) sites by the Licensed Surveyors Association of Ghana (LISAG) to augment the five existing CORS which were established in 2007 by Government of Ghana. However, limited study has been carried out on quality of data from these CORS stations regarding the standards set out by the International GNSS service (IGS) Site Guidelines, 2015. This study presents preliminary reports on pseudorange multipath effects, cycle slips and data completeness in CORS data using Translate, Edit and Quality Check (TEQC) software. The study used data observed simultaneously from receivers mounted at different sites with interstation distances of up to 200km. The results showed noticeable variations in the quality parameters measured at the CORS stations. The Root Mean Square (RMS) values of pseudorange multipath on L1 signal (MP1) and L2 signal (MP2) at the test stations were within the threshold of 0.5m contained in IGS Site Guidelines of 2015. All observed CORS data were available between 99.07% and 100% completeness which is well above the 95% thresholds set by IGS. The CORS stations recorded cycle slip counts fluctuating between 4 and 16. The study concluded that multipath effects in Ghana are location dependent with higher variability. Quality reports on CORS data provide useful information to CORS operators and users for decision making.

Author Biographies

Dr. Osman Mohammed Abukari, Survey and Mapping Division, Lands Commission, Accra, Ghana

Dr. Osman Abukari Mohammed is a Geomatic engineer at the Lands Commission, Ghana. He obtained his Bachelor's degree GEODETIC ENGINEERING in 2012 at the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. Dr. Osman Abukari Mohammed obtained his MSc in Geomatic Engineering in 2015 at the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.He further obtained his PhD in Geomatic Engineering in 2023 at the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. He has been involved in a number of land-mark national survey projects including the establishment of active Continuously Operating Reference Stations (CORS) across Ghana. He also handled a number of property surveys along major road projects such as the Kwame Nkrumah Circle Neoplan Road, the Pokuase Interchange and the Teshie-Nungua Road. His Research interest lies in the following areas: GNSS Positioning Techniques and CORS data
analysis.

Dr. Akwasi Afrifa Acheampong, Geomatic Engineering Department of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

Dr. Akwasi Afrifa Acheampong is a Senior Lecture at the Geomatic Engineering Department of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. He has over 18 years’ experience in consulting, teaching and research in Geo-information data acquisition, analysis and management. More specifically in the field of Accurate and Precise Positioning, GNSS and GIS Applications. Started as a National Service Personal at the Department of Geomatic Engineering at Kwame Nkrumah University of Science and Technology awarded a scholarship to pursue postgraduate studies based on hard work and excellent academic grades. He can work on any survey project on any terrain and with any class of people within the stipulated time frame. Lecturing and being the Field Team Leader with University’s Survey Unit, He has acquired good leadership, interpersonal and computing skills, especially in the use of AutoCAD, ArcView/AcrGIS, MatLab, Trimble Business Centre, RTKlib, gLAB and Spectrum Survey for survey planning, computations, design/drafting and plotting. He has enough technical experience in the use of theodolites, total stations, levels and GNSS/RTK instruments.

Dr. Samuel Osah, Geomatic Engineering Department of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

Dr. Osah Samuel is a Lecture at the Geomatic Engineering Department of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.He obtained his Bachelor's degree GEODETIC ENGINEERING in 2011 at the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. Dr. Osah Samuel obtained his MSc in Geomatic Engineering in 2013 at the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. He further obtained his PhD in Geomatic Engineering in 2022 at the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. He has been involved in a number of land surveying projects including the property surveys for metering by Electricity Company of Ghana (ECG). His Research interest lies in the following areas: GNSS Positioning Techniques and CORS data analysis. His Research interest lies in the following areas: Predictive modelling using Regression techniques and Machine Learning Spatial Statistics or Analysis.

Rev. (Prof.) John Ayer , Geomatic Engineering Department of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

Rev. (Prof.) John Ayer is an Associate Professor at the Geomatic Engineering Department of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana He obtained his Bachelor's degree GEODETIC ENGINEERING in 1991 at the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. Rev. (Prof.) John Ayer obtained his MSc in Geodetic and Geographic Information Systems in 1996 at the University College London, London. He further obtained his PhD in Geomatic Engineering in 2017 at the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. He had been involved in a number of land surveying projects when he worked at the Lands Commission of Ghana. He was involved in the determination of the Transformation Parameters covering the Golden Triangle of Ghana. He holds a license in land surveying in Ghana. His Research interest lies in the following areas: Geodetic surveying, Geographic Information Systems and Mapping. His Research interest lies in the following areas: Predictive modelling using Regression techniques and Machine Learning Spatial Statistics or Analysis.

Published
2023-11-17
How to Cite
Mohammed Abukari, O., Afrifa Acheampong, A., Osah, S., & Ayer , J. (2023). Assessing the Quality of Data from Continuously Operating Reference Stations in Ghana. Journal of Science and Technology, 41(3), 1 - 10. https://doi.org/10.4314/just.v41i3.1640
Section
Articles