Transcript solar-center.stanford.edu

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
Stanford VLF Remote Sensing
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The collaborators
Ionosphere/magnetosphere overview
Electromagnetic effects
SID Receiver
AWESOME Receiver
Educational Outreach
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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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The Ionosphere
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The Magnetosphere
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Electromagnetic Effects
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Sudden Ionospheric Disturbance
Lightning
Whistler Waves
LEP and Early/Fast Events
Mesopheric lightning discharges
 Sprites, elves, blue jets, TGFs
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Sudden Ionospheric Disturbance
 Strong solar flares penetrate to lower
ionospheric region, cause transient changes
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06:38:46
06:03:18
05:27:50
04:52:21
04:16:53
03:41:25
03:05:57
02:30:29
01:55:01
01:19:33
00:44:05
00:08:37
23:33:09
22:57:41
22:22:13
21:46:45
21:11:17
20:35:49
20:00:21
19:24:53
18:49:24
18:13:56
17:38:28
17:03:00
16:27:32
15:52:04
15:16:36
14:41:08
14:05:40
13:30:12
12:54:44
12:19:16
11:43:48
11:08:20
10:32:52
09:57:24
09:21:56
08:46:27
08:10:59
Quiet
Day
07:35:31
07:00:03
SID Event – an Example
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2.5
2
1.5
1
0.5
0
Active
Day
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Lightning Detection
NS
Incident wave S
Φ
EW
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Whistlers in the Magnetosphere
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Whistler Wave – an Example
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LEP/Early Fast Events
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LEP/Early Fast – an Example
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Mesospheric Phenomenon
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Runaway Electrons
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Sprites, TGFs and Sferics
Lightning induced
emissions can be
studied through the
signature of the
lightning’s sferic
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The SID Detector
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Designed by Ray Mitchell
Low cost, compact, easy to use
Narrowband amplitude receiver
1 sample per 5 seconds
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The SID Detector – Overview
All frequencies
Pre-Amp
Coax
24.8KHz
Filter
Signal
Strength
=
10 bit,
Analog to Digital
Conversion
DATAQ
RS-232
Computer
DC voltage
Level
Sample every
5 Seconds
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SID Detector - Pictures
Pre-Amp
Post-Amp
DataQ
Wire Loop Antenna
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The AWESOME Receiver
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Designed by Morris Cohen, Justin Tan
Ultra sensitive
Medium cost (~$2000)
Narrowband amplitude/phase
Broadband 100kHz data A tmospheric
W eather
E ducational
Deployed worldwide
S ystem for
O bservation and
Auto-calibration
M odeling of
E ffects
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AWESOME Receiver – Overview
B-Field
Antenna
Preamp
Long
Cable
GPS
Antenna
Computer
Line
Receiver
Analog to
Digital
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AWESOME Receiver – Pictures
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AWESOME Receiver – Data
Data taken from Palmer Station, Antarctica
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More Data, Calibration
Data taken from Homer, Alaska
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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
 Eventual goal of dozens more
 Distribute selected AWESOME detectors
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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?
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Q u e st i o ns
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