Seismic sensor

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  • Stargate 216 is acting as a gateway and 25 is collecting the data.
  • Take a screenshot.
  • P-wave velocities (Vp) and approx. ray path for P- and S-waves, 18 degrees (~2000 km) distance
  • DO YOU NEED THIS: *************** 100 Seismic stations a 500km line from Acapulco through Mexico City to Tampico 5km – 10 km between stations 100m - 20km wireless links High sensor granularity Multihop wireless 802.11b network taps into internet at various sinks ‘ Real time’ data delivery to UCLA Data analysis on the order of days instead of months Higher granularity of stations Station status available in real time
  • Igor: Could you please provide us with the information? On the right picture the leftmost station is in Acapulco, the rightmost site is somewhere in Pachuca line. Tampico (the last site in the entire line) wasn’t installed at that time. The blemish in the middle is Mexico City. The plot displays the wave propagation time. The more the stations, the better is to localize earthquakes.
  • Transfer files from /opt/test
  • Take a photograph of the assembly
  • Take a snapshot
  • Take a screenshot
  • Take photographs
  • Need to take screenshots
  • Show an example of modifying code, compilation, and installation. Show directory structure of the code. + Change “bufprintf(buf, " ---- Commands: %i Total - Next seqno %i - First seqno %i ----\\n",” to “bufprintf(buf, " ---- IPSN Commands: %i Total - Next seqno %i - First seqno %i ----\\n",”
  • Summarize instructions to build emstar for other platforms
  • ADD A SCALE TO THIS MAP, and add topology info on this slide. Network topology does not reflect physical topology.
  • Seismic sensor

    1. 1. Tutorial about Seismic Sensor NetworkVinayak Naik, Martin Lukac, and Deborah Estrin Information Processing in Sensor Networks (IPSN’07), Cambridge, MA April 24, 2007Acknowledgments to Igor Stubailo, Derek Skolnik, Joey Degges, and Mike Allen for lending us equipments and time.
    2. 2. Special demands of seismic and acoustic applications• Seismic – Large-scale deployment spanning hundreds of kilometers – It’s not easy • Highly varying links with frequent disconnections results in challenged networks • Remote monitoring and fixing of nodes demands services such as reliable broadcast, sink-based data collection, and maintenance of a global state • Developing these services become non-trivial due to challenged networks• Acoustic localization – Sampling rate of the order few KHz – Lew will summarize the challenges
    3. 3. Outline• Using the seismic array out-of-the-box• A few words about seismology• Remotely managing and configuring array after the deployment• Assembling the array in 30 minutes• Adapting the software to fit your needs
    4. 4. What’s in the box?• 1 PC• 3 Cens Data Communication Controller (CDCCs)• 1 Q330 (a combined ADC and data logger)• Ubuntu live CD, which contains – Emstar source code – Emstar code compiled for the i366 and stargate architectures – TFTP server and minicom to reflash the nodes (to be used while assembling the array) – You may also use the CD to install all the required software on your PC or run it in an emulator such as qemu!
    5. 5. Using the CD• Prerequisites: – A computer that can be booted using a CD and has wired ethernet connection – A basic knowledge of Linux, such as use of ssh, scp, and ifconfig• Procedure: – Boot your computer using the CD – Set password for ubuntu: "sudo passwd ubuntu” – setup IP address for the ubutu: “ifconfig eth0 131.179.145.X netmask 255.255.255.0 broadcast 131.179.145.255” – If using a virtual machine, unload USB-to-serial driver if alread loaded
    6. 6. The seismic activities before the start of the tutorial• Stop the data collection process (Duiker)• Transfer data to the base station (PC)• Strip the DTS header from the packet• Uncompress the data• Convert the data from miniseed to ascii format• Transfer data to your laptop• Plot the data using gnuplot Wait, the theory about seismology is coming up.
    7. 7. In situ data collection and presentation• Start Duiker and let it run for 4 minutes• Stop Duiker• Strip the header• Uncompress the data Same as the• Convert the data from miniseed to previous slide ascii format• Transfer data to my laptop• Plot the data using gnuplot
    8. 8. Outline• Using the seismic array out-of-the-box• A few words about seismology• Remotely managing and configuring array after the deployment• Assembling the array in 30 minutes• Adapting the software to fit your needs
    9. 9. Seismology 101Wikipedia: An earthquake is a phenomenon that resultsfrom the sudden release of stored energy in the Earth’scrust that creates seismic waves.There are two types of seismic wave, body wave andsurface wave. There are two kinds of body waves:primary (P-waves), travel fastest through any type of matterand secondary (S-waves), shear, the most destructive.Body waves travel through the Earth’s interior:P-wave speed: 1.5-8 Km/sS-wave speed: 60-70% of the speed of P-wave
    10. 10. Seismic wave energyRichter TNT for Seismic ExampleMagnitude Energy Yield (approximate)-1.5 6 ounces Breaking a rock on a lab table1.0 30 pounds Large Blast at a Construction Site2.0 1 ton Large Quarry or Mine Blast4.0 1,000 tons Small Nuclear Weapon4.5 5,100 tons Average Tornado (total energy)6.5 5 million tons Northridge, CA Quake, 19947.0 32 million tons Japan Quake,1995;Largest Thermonuclear Bomb8.0 1 billion tons San Francisco, CA Quake, 19069.0 32 billion tons Chilean Quake, 196012.0 160 trillion tons Fault Earth in half through center160 trillion tons of dynamite is a frightening yield of energy. Consider, however, thatthe Earth receives that amount in sunlight every day.Because of this huge amount of energy released the seismic waves travel largedistances and make possible to capture them with different kinds of seismicsensors (seismometers).
    11. 11. Seismic sensorsMost signals are composites of many frequencies.Analog with light and sound: Seismic Light Sound Typical seismogram Short-period Blue Treble Long-period Red BassThe long-period and short period instruments are called"narrow" band used for volcano experiment by Harvard. Theysense frequencies near 1/15 s and 1 hertz respectively.The yellow region is the low end of the frequency rangeaudible to most humans, 20 hertz to 20,000 hertz.A broadband instrument senses most frequencies equally well.For our data collection we use the best in its class CMG-3Tbroadband sensor, made by Guralp Systems.Its standard frequency response is 120 s – 50 Hz what Frequency responsesresults in high quality seismic data. of seismometers
    12. 12. About Middle America Subduction Experiment (MASE)• We have a seismic deployment to study the structure of the mantle in Mexico• The deployment consists of wireless stations covering large distances• We developed software to: – Handle collection the seismic data – Manage the seismic system• This tutorial presents this software and how to use it
    13. 13. Seismic deployment application requirements50 standalone Caltech sites • Extensive: 500 Km from Acapulco through Mexico62 wirelessly connected UCLA sites City to Tampico • Dense: 1 sensor every 5-10 Km • High bandwidth: Data acquisition rate: 3 - 24 bit channels at 100Hz each • Online and Reliable: Semi real-time (on the order of days), reliable data delivery to UCLA for analysis • Online system management – Query state, change configuration, update binaries – Can not interfere with data delivery • Application driven topology: application determines sensor placement – Infrastructure does not (Can’t rely on pre-existing cell or power infrastructure) MASE: Given these requirements, we deployed solar powered seismic stations equipped with 802.11b
    14. 14. MASE wireless seismic station 15 dBi YAGI or 24 dBi Parabolic 2.4GHz antenna 70 watt solar panel, GPS mast and guy wires Quanterra Q330 24-bit digitizer sensor controller 2.4GHz amp car battery CDCC (CENS Data Communication Controller) Guralp 3T seismometer
    15. 15. A block diagram of the system’s architectureDTS & file_mover DuikerTCP/IP, UDP CDCC WiFi ethernet Q330 (ADC) Replace with your own Sensor
    16. 16. Pakistan earthquakeOur network:•Achieves almost 10 times better resolution than the previous network as ofOct. 2005 (with 50 sites total). Now it is 20 times better (100 sites)•Provides visualization of the upper mantle and the subduction process,coast to coast across Mexico.
    17. 17. Google video• The data was used to analyze the structure of the earth underneath Mexico• Results are being submitted to the Science journal
    18. 18. Outline• Using the seismic array out-of-the-box• A few words about seismology• Remotely managing and configuring array after the deployment• Assembling the array in 30 minutes• Adapting the software to fit your needs
    19. 19. Networking support needed for both data acquisition and system management• Data delivery – Bandwidth driven – Bandwidth: 20-40 of MB per day per station – Latency: get the data eventually, but reliably – Many to one routing• System Management – Latency driven – Bandwidth: usually less than 10’s of KB’s – Latency: as fast as possible – One to all routing and back
    20. 20. Use of wireless network for remote operation• Demonstrate use of Delay Tolerant Shell (DTS) – Start dtsh – Issue a ps command Configuration – See result of the ps command utilities• Demonstrate the use file transfer – Xfer a file from /opt/test• Demonstrate the use of file mover Data collection – Create a file on a stargate utility – Show the same file on the PC• Xfers – Shows the active transfers• Links Adjunct – Shows existing links on a node utilities• Sink_status – Shows the upstream route to the sink
    21. 21. Challenges handled by DTS, file transfer, and file mover • Frequent unpredictable disconnections – Rainy season: sites flood (some 24x7), trees grow – Wind: misaligned antennas – Equipment malfunction: amps burn, voltage regulators break • Poor and unstable links – Connectivity secondary concern for site selection – Stretched links highly susceptible to weather and environment • Useful tools for operating wireless sensor networks under harsh wireless settings
    22. 22. System management• Existing management tool: remote df –h ls /opt/dts/file_mover | wc shell (ssh) A• Modified management tool: Disruption Tolerant Shell E B – Asynchronous remote shell to all nodes in network simultaneously – Provides node management C D capabilities when end-to-end connections are unavailable or fail F – Ensures that commands will succeed: as long as there is eventually a connection between a node and any other node that already has the command Commands Responses
    23. 23. Data delivery using DTN techniques• Buffer data into hour long bundles (1-3 MB) A• Deliberate one hop bundle transfer• Path to sink determined by best ETX B• Improvement over end-to-end – Not affected by path disconnections C – Keeps retrying on single link instead of full path – Continual ‘progress’ being made towards sink F – More efficient use of bandwidth in face of disconnections and bottlenecks end-to-end hop-by-hop
    24. 24. Extra fun features of DTS• Guaranteed in order execution from source node• Reboot and crash safe• Implicit feed back on nodes and links: spot bottlenecks, dead nodes• Execute a command on individual nodes• Push a file to all nodes – Distribute new script or component
    25. 25. Handling sessions in DTS• A sequence number is assigned per source node per session• Each node publishes a ‘starting sequence number’ across the network – It identifies the oldest command issued by a node that should be in the network – Any commands and responses with sequence numbers below the value (for that particular node) are discarded and not propagated• User controls the starting sequence number – To remove commands from the network, user increments the commands source node starting sequence number – Can choose to do this after all the nodes have reported responses or sooner• Giving control of seqno to user is simple, easy to understand, and efficient• Utilities to handle seqno – Use seqno command to see all the nodes starting sequence numbers – Use incr command to increment the starting sequence number on the current node
    26. 26. Outline• Using the seismic array out-of-the-box• A few words about seismology• Remotely managing and configuring array after the deployment• Assembling the array in 30 minutes• Adapting the software to fit your needs
    27. 27. Ingredients• 3 stargates to form a 1-hop network• 1 computer• 1 serial cable• 1 ethernet hub and 1 ethernet cable
    28. 28. Assembling a seismic node• Connect an episensor to the Q330• Connect Q330 to the wired ethernet hub• Connect a stargate to the wired ethernet• Connect wireless antenna to the stargate• Note that you can substitute Q330 with your choice of data logger
    29. 29. Reprogramming the stargates• Connect PC to the wired ethernet• Connect a serial cable from PC to a stargate• Configure minicom profile called “stargate0”• In stargate-install.exp, change the IP address of the TFTP server to PC’s IP address• Flash the kernel and the root file system – The kernel and the root file system comes with all the seismic software! – Screenshot of the flashing in progress
    30. 30. Configuring a gateway node (base station)• Designate a stargate as a gateway• Restart DTS
    31. 31. Index• Episensor – Measures movement across multiple axes• Q330 – Data logger, GPS, accurate maintenance of time• PDA – Reports status and configures Q330 via infra-red• Williard – A closed-source software to retrieve the data from Q330• Duiker – An open source software to retrieve the data from Q330 – A comparison with Antelope (supports network, open source, and inexpensive)• DTS – An open source software for the remote management of stargates
    32. 32. Outline• Using the seismic array out-of-the-box• A few words about seismology• Remotely managing and configuring array after the deployment• Assembling the array in 30 minutes• Adapting the software to fit your needs
    33. 33. Use of the software for other wireless sensor networks• Replace Q330 with ADC of your choice• Install a driver that collects data from the ADC and creates files on the stargate at /opt/dts/xfer• file_mover will transfer files to the gateway node• No change in DTS and other utilities
    34. 34. Convert existing 7.2/7.3 stargates into seismic nodes• Download dts-whole-system.tar.gz and dts-whole-system-install.tar.gz to /opt on the stargate• Make sure that the script dts-whole-system- install.tar.gz is executable• Execute the script
    35. 35. Adapting the DTS code for your needs• Change code in emstar/devel/dts/dts/dts_status.c• Compile code for stargate architecture• Stop DTS if it is running• Copy the new code to the right place on a stargate• Start DTS and see the change
    36. 36. Convert other platforms into seismic arrays• Portable to Linux-based platforms• Instructions to port EmStar to other platforms
    37. 37. Seismology of the future at CENS• Deploy the CDCCs in Peru• Use of low power LEAP-II nodes instead of stargate• Use of low power and inexpensive ADC boards from Reftek Corp. instead of Q330• Deploy combination of the LEAP-II and the new ADC – For GeoNet to study aftershocks – For structural health monitoring of tall buildings in Los Angeles
    38. 38. A few upcoming features of DTS• Provide visualization of the data movement – Using a coarse grained global time (one second), recreate ‘movie’ of file movement for entire network – Can help spot network problems and bottlenecks• Upload data to SensorBase.org – Makes it easy to visualize and browse data collection status – RSS feed can provide access to anyone who wants to monitor problems or generic status of network• Web interface to simplify operation – Command line interface is nice for Linux pros – Web interface more intuitive for asynchronous model
    39. 39. Thank you• Resources for users and developers – Emstar web-page – Emstar mailing list – Disruption Tolerant Shell in the Proceedings of the 2006 SIGCOMM workshop on Challenged Networks Wish you happy seismography!
    40. 40. Use of seismic sensing• The similarity between the Mexico and LA region• P and S waves• How is the seismic array different from the Harvards volcano motes?• What is the sampling frequency
    41. 41. Need for DTS, file transfer, and file mover• Unreliable links• Need to broadcast commands to the nodes and get responses from the all the nodes• Need to broadcast files to the nodes• Hop-by-hop data movement
    42. 42. %18 - A%152 - B 13 Node Cuernavaca Line L K%69 - C%77 - D Data paths A%107 - E B• Network%42 - F topology does not reflect%81 - G linear physical topologythe mostly%202 - H A – sink%76 - I F Direct inet%106 - J G connection%95 - K D%53 - L C%157 - M E M H I J N

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