IAGA 2010, China Changchun

IAGA 2010, China Changchun

Geomagnetic field measurement and data analysis of the

Cheongyang observatory in Korea

Korea Research Institute of Standards and Science (KRISS)

Po Gyu Park, Wan-Seop Kim

Sung-Dae Hong, Myeong-Son Yu, Se-Jong Lee

Korea Meteorological Administration

Juwan Kim

Chonbuk National University

Better Standards, Better Life

I. Location and purposes

-Geomagnetic Observatory in Cheongyang(CYN) :

operating by KMA

(CYN, 126º 51′ 28″, 36º 21′ 56″, 150 m )- To measure geomagnetic field precisely- To study the possibility of forecasting of

earthquake activity. - To join INTERMAGNET- CYN consisted of 4 huts is located

in a mountainous area


Cheongyang

동해

Korea

Cheongyang (CYN)

Better Standards, Better Life •4

CYN

old temple

Cheongyang (CYN)


II. Instruments and noise measurements

• INTERMAGNET recommendations • 3-axis fluxgate magnetometer(DMI), proton magnetometer (GEM), D/I magnetometer (MinGeo)• Nonmagnetic material used for huts, measurement of magnetic properties for rocks and soil• AC magnetic field noise ( ~1 nT in 60 Hz)• DC magnetic stray field of car effect are measured (Excel car, 0.05 nT in 70 m).• Comparison between Cs-He and proton magnetometer• Absolute measurements (10 months, D=-8º, I=58º)


Magnetic properties(rock) SEM analysis


Rock Magn. Properties

-3 -2 -1 0 1 2 3-0.015

-0.010

-0.005

0.000

0.005

0.010

0.015

M

agn

etiz

atio

n (

emu

)

Applied field (T)

300 K

Paramagnetic !


-3 -2 -1 0 1 2 3

-0.010

-0.005

0.000

0.005

0.010

Mag

net

izat

ion

(em

u)

Applied field (T)

Soil Magn. Properties

Soft ferromagnetic !


Magnetic effect (car)

•Axcell : 0.05 nT ( 70 m )•Tico : 0.05 nT ( 50 m )* Iron(1 T) : 1 nT (100 m )

0 10 20 30 40 50 60 70 680

0

5

10

15

gradiometer

Mc

L 7 m

Cs-

Earth mag. field

Meas. effective car magn. moment - McTico - 173 A.m2

Excel - 520 A.m2

0.0005 nT0.05 nT

: Car "Excel": Car "Tico"

Car

Ma

gne

tic F

ield

( n

T )

Distance,L ( m )


Comparison (Proton and Cs-He)

0.0 0.2 0.4 0.6 0.8 1.0

46448

46450

46452

46454

46456

46458

Kakioka(Overhauser)

Kakioka(Proton)

KRISS(Cs-He AMR)

Kakioka(2010. 4. 22. 1s)

EM

F (

nT)

Time (h)


III. D/I measurement

-Trained by KIGAM(Dr. Lim) and KAKIOKA(Mr. Minamoto)


Declination (Oct. 15 2009-Sept. 7 2010)


Inclination


X-base


Y-base


Z-base


IV. Difference of vector and scalar data

Scalar : Dead zone Vector : orthogonal (3-axis)


0 5 10 15 20 25

50120

50130

50140

50150

50160

50170

50180

Diff

(nT

, Flu

x-P

roto

n)

Proton

3-Axis Flux

EM

F (

nT)

Measurement Time (h, 1 sec, May909)

22

24

26

28

30

32

34

Diff avg : 26.32 nT

Difference of vector and scalar data(1)


0 5 10 15 20 25

50120

50130

50140

50150

50160

50170

50180

50190

10

15

20

25

30

35

40

45

50

Diff avg : 31.63 nT

Diff

(nT

, Flu

x-P

roto

n)

Proton Mag

3-axis Fluxgate

EM

F (

nT)

Measurement Time ( h) (2009. 7. 9. 1sec data)

Difference of vector and scalar data(2)


V. Uncertainty (Error?)

Parameter associated with the result of a measurement,

that characterizes the dispersion of the values that

could reasonably be attributed to the measurand

(VIM2 :International Vocabulary of Basic and General Terms in Metrology)

-ISO Guide, Guide to the Expression of Uncertainty in Measurements(GUM), ISO, 1995.-Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results, NIST Technical Note 1297, NIST, 1993.-Quantifying Uncertainty in Analytical Measurements, EURACHEM, 1995. -DIN 1319-4, Gundlagen der Messtechnik


•Modeling the measurement

•Identifying uncertainty components•for each input quantity

• Evaluating standard uncertainty •Type A, Type B

• Combining standard uncertainties•of input quantities

• Expanded uncertainty

•Coverage factor

•Sensitivity coefficient

5 steps in Meas. Uncer. evaluation

n

su

nsu

sor

),...,,( 21 nxxxfy

ixu

ii x

fc

i

N

i i

xux

fyu 2

2

1

2c )(

2k

)(c yukU

),...(),(),(

3,

2,

1,

i

i

i

xuxuxu


standard uncertainty

Pro. dis ci ui ciui d.o.f.

u(x)

u(xrep)

u(xres)

0.0294

0.0293

0.0029

rectangular

t

rectangular

1

1

1

0.0294 0.0294 ∞ 6

∞

u(c) 0.025 normal 1 0.025 0.025 ∞

uc(m) 0.039 normal ∞

Uncertainty budgets table(ex.)

Extended Uncertainty : coverage factor(k) x Uc * ( Confidence level 95%, k=2 )

ex) Total intensity : (49598.2 ± 0.1) nT ((Reading-0.5)±0.1) nT


VI. Future work(CYN)

- D/I measurement continually

- Comparison (Proton and Cs-He Magn.)

- Evaluation of uncertainties(MFD, D/I?)

- Join in INTERMAGNET in 2011

- Time sync. for 1 s data

- Contribution to Geomagnetic society


Purpose of magnetic compass?

KRISS

A propitious site for a grave


1. V. Ya. Shifrin, Po Gyu Park et al., “Experimental estimation of the accuracy of medern scalar quantum magnetometer…”, Phys. Ear. Plan. Inter. 166(2), pp.147-152(2008).

2. P. G. park, Y. G. Kim, V. Ya. Shifrin, "Maintenance of Magnetic Flux Density Standards on the Basis of Proton Gyromagnetic Ratio at KRISS" IEEE Trans. Instrum. Meas. 54(2), pp.734-737(2005).

3. V. Ya. Shifrin, V.N.Khorev, A.Ye.Shilov and P.G.Park, “The long-term stability of an atomic magnetic resonance standard system…’, IEEE Trans. Instrum. Meas. 52(2), pp.433-435(2003).

4. P. G. Park, Y. G. Kim, V. Ya. Shifrin, and V. N. Khorev, "Precise standard system for low dc magnetic field reproduction", Rev. Sci. Instrum., 73(8), pp.3107-3111(2002).

5. V. Ya. Shifrin, E. B. Alexandrov, T. I. Chikvadze, V. N. Khorev, Po Gyu Park, “Magnetic flux density standard for geomagnetometer”, Metrologia, 37(3), pp.219-227 (2000).

6. V. Ya. Shifrin, Po Gyu Park, V. N. Khorev, Chang Ho Choi, C. S. Kim, “A New Low-Field Determination of the Proton Gyromagnetic Ratio in Water”, IEEE Trans. Instrum. Meas. 47(3), pp.638-643(1998).

7. V. Ya. Shifrin, Po Gyu Park, Cheol Gi Kim, V.N. Khorev, Chang Ho Choi, “Experimental Determination of the Gyromagnetic Ratio of the He-4 Atom in Terms of that of the He-3 Nucleus”, IEEE. Trans. Meas. Instrum IEEE Trans. Instrum. Meas. 46(2), pp. 97-100 (1997).

References

IAGA 2010, China Changchun

Documents

Transcript of IAGA 2010, China Changchun