Group 12 Subterranean Fourier Transformers Chris Springer, Andrew Duncan, and Adam Kassar

 Introduction  Problem Statement  Needs  Project Background  Original Design  Overall Architecture ▪ Level Zero Architecture ▪ Level One Architecture  Major Technologies  Creative Aspects  Challenges to System Development  Actual Implementation (Design Changes/Deviations)  Additional Technologies Used  Technical Details of TTE Communication Project  Going Forward  Demo

 Meet a clearly articulated need to save the lives of trapped miners during mining incidents by developing a low frequency TTE communication system to be utilized for miners  While keeping the main problem statement in mind, the group is continuing the work of current and past EE 480/481 groups  Mentor: Dr. Nutter

 Meet safety regulations  All MSHA CFR 30 Standards  Rugged  Must be able to withstand impacts and physical abuse  Compact/Lightweight  Miners must be able to carry a large amount of equipment into cramped areas  Low Power  Unsafe for high power signal broadcasting  Ensures long battery life

 Communicating with miners is as old of a problem as the occupation itself  Noisy environment  RF communication TTE is no easy task  No two-way underground-surface communication system currently exists

 Two way through the earth communication is not possible with current technology  High radio frequencies (RF) scatter when propagating through the Earth’s crust  Wide band transmissions are below the noise floor and thus non-detectable  Proposed Solution  Spread Spectrum at Ultra Low Frequencies (ULF)

 Current Technologies approved by MSHA (Mine Safety and Health Administration)  Walkie-Talkies  Leaky Feeder Communication Systems  Mine Page Phones  RFID (Radio Frequency Identification) Tracking Systems  PED (Personal Emergency Device)

 Chilean mine collapse of 2010  33 miners trapped underground  Took 17 days to find them ▪ Why?

 Overall Architecture  Level Zero Architecture  Level One Architecture  Level Two Architecture  Use Case  User Interface Specification  Keypad  LCD (Liquid Crystal Display) Screen  Dataflow Diagram  State Transition Diagram  Circuit Diagram

 Two Induction Loop Antennas  Previous EE 481 groups designed induction loop antennas with 30 turns Transmit AntennaReceive Antenna

 Magister  Field Programmable Gate Array (FPGA) hardware used to interface other cards with a PC via USB

 Janus  Analog-to-Digital converter  Digital-to-Analog converter

 Use Existing Open Source HAM Radio Software/Hardware  PowerSDR  GNURadio  Janus/Magister Cards  Digital Signal Processing Algorithm  Spread spectrum  Detect low-power signals at Ultra Low Frequencies

 Low power  Ultra Low Frequency  Needed for through the earth propagation  Product Size  Mine Safety and Health Standards  Completing project on time

 Lab bench prototype  Able to send and receive ASCII characters  Operate in an electrically-noisy environment  I and Q Spread Spectrum Algorithm  Two Way Communication

 Status of Original Expected Outcome  Completed Successfully with some Exceptions ▪ Two way communication was not part of the design due to limited resources (future groups can build upon our design to implement two way communication) ▪ LCD was not used as primary user interface….instead software was used to create GUI’s (graphical user interfaces)  Lab Bench Prototype  Two induction loop antennas ▪ One receive(Rx) antenna and one transmit (Tx) antenna  Two Software Scripts with Gui’s ▪ txGUI.py and gui.py  Audio Amplifier Sub Woofer (thanks to Adam)  Two PC’s and HPSDR Hardware  Preamp

 In addition to the technologies previously specified, the following technologies were used.  Software Development Tools ▪ MATLAB ▪ Python ▪ wxPython 2.9 ▪ SciPy 0.12 ▪ Numpy ▪ Matplotlib ▪ PyAudio

 Additional Technologies  Quintessential Hardware ▪ Multi-Stage Pre Amp ▪ 60 Hz Transformer with rated values ▪ Impedance match antenna to audio amplifier ▪ Three PC’s (one to operate transmit gui, one to operate receive gui, and one to stream data from powerSDR to other PC)

 To begin the EE 481 course, the status of the previous group’s project was not fully understood  Solution: Stay in close contact with our advisor/mentor Dr. Nutter  Try to meet at least once a week in order to keep him up to date with most recent designs and algorithm developments related to project  Dr. Nutter assigned the Graduate Student (Zennaeh) to design and build the I and Q circuit  I => In phase Quadrature  Q => Out of Phase Quadrature

 Close consultation with Dr. Nutter led us to the realization that no electrical properties or characterizations existed for the two induction loop antennas Dr. Nutter wanted us to utilize  Decent amount of time characterizing the electrical properties of the antennas  Next two slides portray the electrical properties of the transmit antenna and the receive antenna  Antennas act more resistive then inductive ▪ Propagation is not optimal for the purpose of this project ▪ Proof of concept

 Design and Construction of Preamp

 Software for Transmit and Receive  Transmit Communication Scheme ▪ ULF Band FSK (not true spread spectrum)  Receive Script ▪ Streams data from SDR software to Python gui.py script and displays the audio (ULF) spectrum of the data in a logarithmic scale or linear scale ▪ Displays the received message in the log window as well as the last message received on the GUI

 Antenna Development  Purchase better antennas or propose idea to design new antennas  Implement Two Way Communication  Obtain necessary resources and write software to handle two way communication  Implement a better modulation scheme  Software developed this semester allows for easy testing

 To conclude this presentation, we will show a video of a demo of our project and communication system to provide you a visual understanding of the technical workings of our project.