Wireless Geophone Networks

Oil and gas industries have been directing their interest and resources towards monitoring and exploring the Earth’s subsurface and its underlying stratigraphy/structure. They have increased their investments in seismic exploration to discover new hydrocarbon reservoirs in pursuit of efficient production. The tendency towards wireless seismic acquisition has motivated many researchers and companies to investigate Wireless Geophone Networks (WGNs) as a transition from traditional cable-based seismic acquisition systems in exploration. During these surveys, geophones are placed at the surface -typically in an array configuration- to cover the area under exploration, then they detect reflected waves, e.g. P- and S-waves, surface waves, after a seismic sweep by truck-mounted vibrators on ground. Upon proper processing of the collected seismic data from all geophones, high quality seismic images/maps of the subsurface can be obtained. We have investigated and proposed novel WGN architectures for high-density seismic acquisition with high-speed and efficient power consumption in collecting seismic data.

Underwater Wireless Communications

Underwater wireless communication has recently attracted attention for many applications including oceanographic data collection, pollution monitoring, seismic activities measurement, exploration of natural resources among others. Orthogonal frequency division multiplexing (OFDM) combined with multi-relay cooperative transmission provides additional spatial diversity compared to conventional non-cooperative underwater acoustic (UWA) systems. We have analyzed the Intercarrier interference (ICI) due to non-uniform Doppler distortion, proposing different receiver structures, and deriving expressions for ICI matrices. We have also investigated the outage performance for a cooperative OFDM UWA communication system, both amplify-and-forward (AF) and decode-and-forward (DF) relaying schemes. Analytical expressions as bounds on outage probability and outage capacity were derived. Monte-Carlo simulations corroborate the enhanced performance of cooperative OFDM UWA communication systems.