Journals Information
Universal Journal of Geoscience(CEASE PUBLICATION) Vol. 1(1), pp. 10 - 19
DOI: 10.13189/ujg.2013.010102
Reprint (PDF) (1963Kb)
Geophysical Mapping of Subsurface Stratigraphy Beneath A River Bed Using Ground Penetrating Radar: Lagos Nigeria Case Study
Adepelumi A. A.*, Fayemi O., Akindulureni J.
Department of Geology, Obafemi Awolowo University, Ile-Ife, Nigeria
ABSTRACT
Ground penetrating radar (GPR) has been found to be most suitable for subsurface stratigraphic and lithologic mapping. In this study, we showed its application in bathymetric study in the region where a proposed pedestrian bridge across a river channels is planned. The application of a novel digital signal processing approach applied to the GPR acquired is shown. The methodology adopted involved the acquisition of GPR data along a 100 m transect, across the river using a 200 MHz GSSI SIR equipment. The GPR data was processed using the sequence viz: 1) Dewowing 2) Filter in frequency domain 3) Custom Gain 4) Automatic gain control 5) Delete Mean trace and 6) Deconvolution. In addition, complex processing methods (Instantaneous attribute) was applied to increase interpretability of the GPR data. The performance of each processing step is compared by examining its result. The study shows that filtering in frequency domain; gain application and delete mean trace are the basic processing steps used in low noisy data acquired with GSSI equipment. From the processing, it was evident that deconvolution is very effective in removing reverberation and/or multiples from the dataset. Delete mean trace produced the best result in removing high amplitude, continuous horizontal reflections (such as direct wave) that conceals true reflections. Even though these methods were effective, each method has its own advantages and limitations. Therefore, preservation of the geological features should supersede any other motive or decision made during GPR data processing. Among the complex processing methods, Instantaneous phase proved to be most resourceful for bathymetric study. The Interpreted section revealed the base of the river at a depth of 5 m. A good knowledge of the river geometry which will help civil engineers in proper planning of the bridge footings structure was also obtained.
KEYWORDS
Ground Penetrating Radar (GPR), Basic Processing Bathymetric Study, Instantaneous Attribute, Bridge Footing
Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Adepelumi A. A. , Fayemi O. , Akindulureni J. , "Geophysical Mapping of Subsurface Stratigraphy Beneath A River Bed Using Ground Penetrating Radar: Lagos Nigeria Case Study," Universal Journal of Geoscience(CEASE PUBLICATION), Vol. 1, No. 1, pp. 10 - 19, 2013. DOI: 10.13189/ujg.2013.010102.
(b). APA Format:
Adepelumi A. A. , Fayemi O. , Akindulureni J. (2013). Geophysical Mapping of Subsurface Stratigraphy Beneath A River Bed Using Ground Penetrating Radar: Lagos Nigeria Case Study. Universal Journal of Geoscience(CEASE PUBLICATION), 1(1), 10 - 19. DOI: 10.13189/ujg.2013.010102.