Abstract
Consistency is an important characteristic in height systems which the mean sea level (msl) surface cannot guarantee. Only a geoid surface can provide height consistency. The quality of geoid undulation (N) will obviously affect the resulting orthometric height (H) determined from GNSS. The geoid undulation may be global, regional/national and local. Online software CSRS-PPP was used for post processing rinex data. 𝑁𝐸𝐺𝑀2008 was computed from AllTrans EGM2008 geoid calculator while h was used to compute 𝑁𝐺𝑃𝑆 from the relationship N= h-H. H is the existing orthometric height. Twenty-four controls with FCT 260 P as base reference station were used for this study. The computed standard deviation of differences in 𝑁𝐺𝑃𝑆 − 𝑁𝐸𝐺𝑀2008 (σ) is used as accuracy indicator and σ =0.419m .The root mean square error (RMSE) is 0.934m. This indicates the quality and reliability of the geoid undulation from the EGM2008 model. Comparing the observed 𝑁𝐺𝑁𝑆𝑆 and 𝑁𝐸𝐺𝑀2008, the use of global models may not satisfy the accuracy level of orthometric height desired for local applications in the FCT, Abuja. GNSS (GPS) may be used along with local geoid model as a way to acquire acceptable orthometric height. The smaller the 𝑁𝐺𝑃𝑆-𝑁𝐸𝐺𝑀2008 makes it better model. The range of 1.585m from (𝑁𝐺𝑃𝑆-𝑁𝐸𝐺𝑀2008) in this study is a strong indication that global models should be avoided as much as possible in local applications.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
