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Stanford VLF Remote Sensing Science, Engineering, Educational outreach Morris Cohen Along with Phil Scherrer, Deborah Scherrer, Umran Inan, Ray Mitchell, Justin Tan Space, Telecommunications and Radioscience Laboratory Stanford University Stanford, California 94305 http://www-star.stanford.edu/~vlf/ http://sun.stanford.edu
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2 Stanford VLF Remote Sensing The collaborators Ionosphere/magnetosphere overview Electromagnetic effects SID Receiver AWESOME Receiver Educational Outreach
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3 The Stanford Collaborators Phil/Deborah Scherrer Ray Mitchell Umran Inan Morris Cohen Justin Tan Center for Integrated Space Weather Modeling (CISM)
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4 The Ionosphere Source: HAARP
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5 The Magnetosphere Source: NASA, Rice University
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6 Electromagnetic Effects Solar Flare Detection Cosmic Gamma Rays Chorus Emissions Lightning Whistler waves LEP Events, hurricane studies Early/fast Events Mesospheric lightning discharges Sprites, elves, blue jets, TGFs
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7 Sudden Ionospheric Disturbance Strong solar flares penetrate to lower ionospheric region, cause transient changes
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8 VLF Transmitters Source: Great Circle Mapper, Karl Swartz
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9 SID Event – an Example Quiet Day Active Day NLK 24.8 kHz Source: Ray Mitchell
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10 SID Event – an Example GOES Data Active Day NLK 24.8 kHz
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11 Cosmic Gamma Rays
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12 Chorus Emissions
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13 Lightning Detection EW NS Incident wave S Φ
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14 Whistlers in the Magnetosphere
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15 Whistler Wave – an Example
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16 Lightning Induced Electron Precipitation (LEP Events) Source: Bill Peter
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17 LEP Events – an Example Hurricane Isabel
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18 Early Fast Events Source: Bill Peter
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19 Mesospheric Phenomenon Source: Nikolai Lehtinen
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20 Runaway Electrons Source: Nikolai Lehtinen
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21 Sprites and Early/Fast Events Early fast events are highly correlated with sprites, indicating connection with ionospheric heating and runaway electrons Source: Robert Marshall
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22 TGFs and Sferics
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23 The Hardware SID Detector AWESOME Receiver A tmospheric W eather E ducational S ystem for O bservation and M odeling of E ffects
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24 The SID Detector Designed by Ray Mitchell Low cost, compact, easy to use Narrowband amplitude receiver 1 sample per 5 seconds
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25 The SID Detector – Overview Pre-Amp 24.8KHz Filter Signal Strength DATAQ Computer RS-232 Coax = All frequencies DC voltage Level 10 bit, Analog to Digital Conversion Sample every 5 Seconds Source: Ray Mitchell
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26 SID Detector - Pictures Pre-Amp DataQ Post-Amp Wire Loop Antenna Source: Ray Mitchell
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27 The AWESOME Receiver Designed by Morris Cohen, Justin Tan Ultra sensitive Medium cost (~$2000) Narrowband amplitude/phase Broadband 100kHz data Deployed worldwide Auto-calibration
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28 AWESOME Receiver – Overview B-Field Antenna Preamp Long Cable Line Receiver Analog to Digital Computer GPS Antenna
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29 AWESOME Receiver – Pictures
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30 AWESOME Receiver – Data Data taken from Palmer Station, Antarctica
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31 More Data, Calibration Data taken from Homer, Alaska
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32 Educational Outreach Center for Integrated Space Weather Modeling (CISM) Run by Boston University Stanford selected for educational outreach Distribute SID detectors widely 3 Beta sites working 100 units in production 3 foreign sites planned (Tanzania, India, Tibet) Distribute selected AWESOME detectors
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33 Educational Outreach (con’t) Research purpose data sent to Stanford via internet, DVDs Educational purposes Monitor solar flares/VLF activity Build antenna, maintain electronics Participate in research campaigns Promote in developing countries through UN? http://solar-center.stanford.edu/~SID http://www-star.stanford.edu/~hail/
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34 nQeitouss ?
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