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Ahmed Mohammed

Ahmed Mohammed

Coordinate time series data for analysing geophysical processes.


Project description

We use long period coordinate time series data for analysing geophysical processes. Not removing the inherent unmodeled signals has a significant impact on the output prediction or inference.

Most time series analysis needs to separate deterministic periodic oscillations from random and aperiodic fluctuations. These fluctuations contribute to unresolved background noise, or unwanted geophysical variability. Systematic errors are often due to limitations in the mathematical algorithm/model that leads to short and long term signals. Assessing these errors is vital if we are to use episodic campaign data for geophysical studies.

I am using scientific GNSS analysis software to investigate the effect of surface mass loading and tropospheric delays on instantaneous coordinates. The GNSS-based reference frame includes Nigeria and surrounding parts of the African continent.

I will estimate the unmodelled short and long term loading effects on single and combined systems signals from GNSS time series data. This will take care of errors due to ocean loading, atmospheric pressure loading and tropospheric delay. I will then use the estimate to correct GNSS observations data. This will help to estimate coordinates and velocities in Nigeria and surrounding parts of the African continent. It will also provide a GNSS-based regional geodetic reference frame of the research area.

The Petroleum Technology Development Fund (PTDF) sponsors the research. The PTDF is an agency in Nigeria under the Federal Ministry of Petroleum Resources. It has the vision and mandate of being instrumental in the development of indigenous manpower and technology acquisition in the Petroleum Industry in Nigeria.


Investigating GNSS noise characteristics and its application in monitoring geophysical processes.


  • MTech Surveying and Geoinformatics
  • BTech Surveying and Geoinformatics