The Mine Improvement and New Emergency Response (MINER) Act of 2006 was enacted in response to several coal mining accidents that occurred in the beginning of 2006. The MINER Act does not just require underground mines to integrate wireless communication and tracking systems, but aims to overall enhance health and safety in mining at both surface and underground operations. In 2006, the underground communication technologies available to the mining industry had inherent problems that limited communication capabilities. Since the passage of the MINER Act, there have been several developing applications for underground wireless communications. Underground wireless communications allow signals to propagate and take multiple paths to destinations providing a survivable, redundant, and adaptable means of communication and tracking. An underground wireless communications allow underground and surface personnel to directly correspond to one another without being as restricted as hardwired systems. Communication systems also allow miners to be tracked underground to provide a real-time or last known post-accident position, and ensure a more efficient rescue operation. In order to increase the overall efficiency of developing communication systems there is a need for modeling of wireless signal propagation in underground mines. Research, modeling, and analysis of wireless signal propagation in underground mines ongoing and developing with underground communications systems as the systems progress. The work on this project is based upon the Accolade system from L-3 Communications Global Security and Engineering Solutions but applies to all underground wireless mesh systems currently available. A general approach is taken to solving underground wireless communications networks to allow the design criteria to be adaptable to other communication systems belong the Accolade system. The data is based upon measurements and field work that took place July 2007 through December 2008 in International Coal Group's Sentinel Mine in Philippi, West Virginia. Comms, a computer method developed at the Virginia Center for Coal and Energy Research at Virginia Tech, allows underground mine communication networks to be solved and analyzed. Comms was developed to solve and analyze underground wireless communication networks. The method which Comms solves communication networks is not mine specific and may be adapted to predict the performance of a system(s) in another mine. The developed model discussed in Chapters 3 and 4 highlights the general signal loss parameters that are encountered by wireless signals in a mine. The model predicted the signal strength observed when encountering those categorized signal losses within 16 percent of the data measured during a mine survey. The model has been developed in a general manner to allow future investigation and pinpointing of additional interferences that occur within the underground environment. Wireless communications have proven to be the way of the future and will continue to be integrated into underground coal mines as mandated by the MINER Act. Wireless communications systems are a redundant and survivable means of communication that will be utilized in not only emergency and rescue efforts but daily operational communication as well. / Master of Science

Wireless Underground Sensor Networks (WUSNs) are the networks of wireless sensors that operate below the ground surface. These sensors are either buried completely in soil medium, or placed within a bounded open underground space, such as underground mines and tunnels. WUSNs enable a wide variety of novel applications, including intelligent irrigation, underground structure monitoring, and border patrol and intruder detection. This thesis is concerned with establishing reliable and efficient communications in the network of wireless sensor nodes that are deployed in either soil medium or underground mines and tunnels. In particular, to realize WUSNs in soil medium, two types of signal propagation techniques including Electromagnetic (EM) waves and Magnetic Induction (MI) are explored. For EM wave-based WUSNs, the heterogeneous network architecture and dynamic connectivity are investigated based on a comprehensive channel model in soil medium. Then a spatio-temporal correlation-based data collection schemes is developed to reduce the sensor density while keeping high monitoring accuracy. For MI-based WUSNs, the MI channel is first analytically characterized. Then based on the MI channel model, the MI waveguide technique is developed in order to enlarge the underground transmission range. Finally, the optimal deployment algorithms for MI waveguides in WUSNs are analyzed to construct the WUSNs with high reliability and low costs. To realize WUSNs in underground mines and tunnels, a mode-based analytical channel model is first proposed to accurately characterize the signal propagation in both empty and obstructed mines and tunnels. Then the Multiple-Input and Multiple-Output (MIMO) system and cooperative communication system are optimized to establish reliable and efficient communications in underground mines and tunnels.

Baigiamajame magistro darbe nagrinėjama požeminių komunikacijų vizualizacija trimačiame modelyje. Šiame magistriniame darbe išnagrinėta 3D duomenų svarba ir pranašumas prieš 2D vizualizavimą. Buvo atliktas požeminių komunikacijų projektavimo tyrimas trima��io vaizdavimo programine įranga, ištirtas šių technologijų naudojimas užsienyje bei naudojimo perspektyvos Lietuvoje. Darbą sudaro 10 dalių: įvadas, informacijos vizualizavimo aplinkos, 3D duomenų modelio esmė, 3D programinės įrangos galimybės inžinerijoje,3D vizualizavimo programinė įranga,3D modeliavimo koordinačių sistemos, trimačio geoinformacinių sistemų modelio sudarymas, požeminių komunikacijų trimačio geoinformacinių sistemų modelio sudarymo metodika, požeminių komunikacijų duomenų surinkimo reikalavimai, požeminių komunikacijų 3D skaitmeninio modelio kūrimas, požeminių komunikacijų trimačio modelio naudojimas Lietuvoje ir pasaulyje,išvados, literatūros sąrašas. / In the magistrate thesis are researching visualization of Underground communications at 3D data model. In the thesis analyse 3D model data significance and advantage against 2D model data. Also researching program equipment projection of Underground communications 3D data model, technology usage in foreign countries and opportunities for use in Lithuania. Structure: introduction, information visualization surrounding, 3D data model essence, 3D data program equipment opportunity in the engineering, 3D data model equipment, 3D data model coordinate systems, 3D data model formation, formation model of underground communication at 3D data model, data assemblage standards of underground communications, underground communication 3D data model creation, 3D data model usage in the world and Lithuania, conclusions, references.