how did ucla develop the world s largest ground magnetometer network an insider s account n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
How Did UCLA Develop the World’s Largest Ground Magnetometer Network ~ An insider’s account ~ PowerPoint Presentation
Download Presentation
How Did UCLA Develop the World’s Largest Ground Magnetometer Network ~ An insider’s account ~

Loading in 2 Seconds...

play fullscreen
1 / 21

How Did UCLA Develop the World’s Largest Ground Magnetometer Network ~ An insider’s account ~ - PowerPoint PPT Presentation


  • 79 Views
  • Uploaded on

How Did UCLA Develop the World’s Largest Ground Magnetometer Network ~ An insider’s account ~. Peter Chi IGPP & ESS, UCLA Prof. Russell Symposium May 8-9, 2013. Once Upon a Time (circa 1992).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'How Did UCLA Develop the World’s Largest Ground Magnetometer Network ~ An insider’s account ~' - dreama


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
how did ucla develop the world s largest ground magnetometer network an insider s account

How Did UCLA Develop the World’s Largest Ground Magnetometer Network~ An insider’s account ~

Peter Chi

IGPP & ESS, UCLA

Prof. Russell Symposium

May 8-9, 2013

once upon a time circa 1992
Once Upon a Time (circa 1992)
  • Chris suggested me, a new graduate student from Taiwan, to study ground magnetometer data for my graduate research.
  • At that time UCLA was not operating ground magnetometers.
  • But a few sets of ground magnetometer data were studied with great interest (e.g. IGS data from UK; AFGL data from Howard Singer and Jeff Hughes)
  • Research using ground magnetometer data: Ultra-low-frequency (ULF) waves; Subsurface conductivity inferred from wave amplitude

AFGL array

Chi et al. [1996]

1995 renewed interest in ground magnetometers small type fluxgate magnetometers
1995: Renewed Interest in Ground MagnetometersSMALL-type Fluxgate Magnetometers
  • Made use of desktop PC for housing electronics, acquiring and storing data
  • Included a GPS for accurate location and time
  • A low-cost system that made it economically feasible for many research projects
1995 early 2000s small igpp lanl arrays
1995- early 2000s:SMALL & IGPP-LANL Arrays
  • PI: Guan Le
  • Chris organized a meeting with Chinese PIs at UCLA
  • A dozen stations were established in China
  • PI: V. Angelopoulos, C. T. Russell
  • Domestic ground observations since AFGL magnetometer project, paving the way for more ground projects in North America
detecting field line resonance flr from the ground
Detecting Field Line Resonance (FLR)from the Ground

Russell et al. (1999):

Using IGPP-LANL data

Chi et al. (2000): Using IGPP-LANL data

Chi and Russell (1998)

slide8

(2005 -): Mid-continent Magnetoseismic Chain (McMAC)

● Field line resonance method requires close separation between ground stations in the north-south direction.

● The mean north-south separation between two adjacent McMAC stations is 275 Km.

● Joint operation with CANOPUS Churchill Line (Canada), IGPP-LANL (U.S.) and MAGDAS (Japan) provides the magnetic field data from L = 1.2to 11+ at one local time.

automated detection of flr frequencies
Automated Detection of FLR Frequencies
  • We developed an algorithm to automated detection of FLR frequencies in cross-phase/cross-power spectrograms.
  • The algorithm is based on the criteria used by Berube et al. (2003) with additional constraints.
  • We examined the results in cross-phase spectrograms but rarely needed to make corrections.
  • Peaks in cross phase
  • Coherence
  • t-statistic
  • Positive slope in power ratio
  • Remove isolated selections
local time dependence of density
Local Time Dependence of Density

Theremosphere

Plasmasphere

  • Plasmasphere: Density increases in afternoon/evening hours are not predicted by models.
  • Thermosphere: Equatorial ionization anomaly peaks in local afternoon at low magnetic latitudes.
  • Reason: Neutral plasma coupling

Equatorial

Lühr et al. [2011]

other ucla built ground magnetometers s ince late 1990s
Other UCLA-built Ground Magnetometers Since Late 1990s

MEASURE

PI: Mark Moldwin

Region: US East Coast

PI: Martin Connors

Region: Canada

AMBER

PI: EndawokeYizengaw

Region: Africa

SAMBA

PI: EftyhiaZesta

Region: South America/Antarctica

themis ground magnetometers 2003
THEMIS Ground Magnetometers (2003-)
  • System Features
  • • ±72KnT dynamic range @ 0.01nT Resolution (~23 bits)
  • • Offset DAC system for 256 possible ranges per axis
  • Sigma-delta modulator design
  • • 2 vectors per second data rate
  • • Low power < 4W
  • • Small size 22cm x 13cm x 5cm
  • • Ruggedized all weather sensor design
  • • USB interface for data retrieval and firmware upload
  • • GPS antenna and electronics Integrated into one package
  • • NTP compatible (1msec time accuracy)
effective station pairs for flr sounding in north america
Effective Station Pairs for FLR Sounding in North America
  • Magnetometer Arrays:
  • McMAC
  • Falcon
  • THEMIS GBO/EPO
  • USGS
  • IGPP/LANL
  • GIMA
  • CARISMA
  • AUTUMN
  • CANMOS

(During 23-26 October 2007)

monitoring equatorial density by ground magnetometers
Monitoring Equatorial Density byGround Magnetometers

2007-Oct-25

log10 (neq)

[a.m.u. cm3]

travel time magneto seismology
Travel-time Magneto-seismology

Spacecraft

Ground stations

slide17

Ultra Large

TerrestrialInternational Magnetometer Array

  • An international consortium for ground-based magnetometers since 2006.
  • Provides a platform for ground-based magnetometer networks to collaborate.
  • ULTIMA and mini-GEM have been holding joint meeting sessions on an annual basis. ULTIMA looks forward to continuing this practice that helps interact with other scientists/projects.

ULTIMA kick-off meeting at UCLA (2006)

conclusions
Conclusions
  • Since mid-1990s, UCLA and collaborators have developed the world’s largest ground magnetometer network in 15 years
  • What made it happen:
    • Persistent support and leadership by Prof. Russell
    • Engineering innovations and scientific quests
    • Joint ventures between UCLA Team and Collaborators
    • Unconditional love
    • Spirit of exploration