• Member of World Wide Lightning Location Network
• Staff-Student Liaison Committee FSTE
• Member IEEE
AREAS OF EXPERTISE
• Electrical communication, Radio wave propagation
• Quantum and Electrical Physics, Electromagnetism
• Very Low Frequency radio wave techniques to study the Earth’s atmosphere (lower ionosphere).
• Study of tweek atmospherics and low latitude whistlers generated by lightning discharges.
• Scintillation of radio wave signals due to ionospheric irregularities.
• The study of the Earth’s upper atmosphere using VLF radio waves is a well developed technique. Lightning generated electromagnetic signals also known as atmospherics (sferics in short) have a peak spectral density of around 10 kHz. These signals can propagate very large distances in the Earth-Ionosphere waveguide through multiple reflections between the Earth surface and the ionosphere. In my research I have studied atmospherics that has traveled large distances and appear as tweeks (with a dispersion near their cutoff frequency) in a spectrogram. Tweek sferics have been used to estimate the nighttime height of the ionosphere and the total propagation distance to the source discharge. The system used under the World Wide Lightning Location Network also recorded a low-latitude whistler which I had analyzed.
• Ionospheric scintillation measurements are also a well developed technique used to probing the upper atmosphere. Scintillation is the rapid fluctuation of phase and amplitude of trans-ionospheric radio waves as they traverse through ionization irregularities in the ionosphere. I measured a beacon signal at 3.925 GHz from the geostationary satellite Intelsat (701) situated at 180o E to study ionsopheric scintillation in the SHF band. The measurements indicated very weak scintillation activity with S4 index < 0.3. Daytime scintillation activity was prominent over nighttime indicating prominence of Sporadic-E irregularities in the ionosphere during low solar activity.
• Title: “Spectral induced polarization measurement of Geological media”. Spectral induced polarization (SIP) is a well known mineral exploration technique. It has become an important non-intrusive geophysical technique for geotechnical and engineering related studies. Presently SIP studies focus on either a) field applications for subsurface characterization, and b) laboratory studies for understanding and evaluating the effect of different pollutants on the SIP response of soils. In this work we intend to develop capacities at USP for laboratory based SIP studies, which in future can be extended to engineering materials such as concrete and asphalt.
• Title: “Corrosion Impact on Marine Infrastructure in Fiji”. In this project the self-potential technique is used to monitor rebar corrosion on concrete in the marine environment.