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STAFF-SC / FGM Comparison. Cross_Calibration Workshop ESTEC, Noordwijk, 2-3 february 2006. P. Robert, CETP. A. Reminder on old comparisons (IC, London, February 2001). B. New comparisons. I. Spectrograms comparison. II. Average spectra comparison. III. Wave Forms comparison. - PowerPoint PPT Presentation
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STAFF-SC / FGM Comparison
I. Spectrograms comparison
II. Average spectra comparison
III. Wave Forms comparison
IV. Noise Level
Conclusions
Cross_Calibration Workshop ESTEC, Noordwijk, 2-3 february 2006
P. Robert, CETP
A. Reminder on old comparisons (IC, London, February 2001)
B. New comparisons
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
A. Old comparisons (IC, London, February 2001)
Original FGM High res. Files provided by M. Dunlop
Already STFF-FGM difference on perp. DC field
A.1 Spectrogram
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
A. Old comparisons (IC, London, February 2001)
Original FGM High res. Files provided by M. Dunlop
Sensitivity differs beyond 1 Hz
A.2 Average Spectra
Rather good agreementBetween STFF-FGM
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
B. New comparisons (February 2006)
All following result has done with FGM high res. DataProvided by FGM Dapclus software,
using cal tables downloaded from I.C.
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
I.1 Bx,By,Bz SC1I. Spectrograms comparison
OKRest of spin effect, OK
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
Position in space
18:0024:00 21:00
22:00
Tetrahedron size about 1200 km
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
I.2 Bz ALL S/C
OK
Pb !
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
I.3 Bperp ALL S/C
FGM
STAFF
1) STAFF < FGM,
2) STAFF Pb on S/C # 1
Sometimes up to 20%When strong DC field
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
I.3 Bperp SC1 and SC2
FGM
STAFF
2) STAFF Pb on S/C # 1
1) STAFF < FGM, Diff=1 nT or 16% on SC1, Diff=0.5 nT or 8% on SC2
Sometimes up to 20%When strong DC field
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
II. Average spectra comparison II.1 Bx,By,Bz SC1
STAFF FGM
Sensitivity loss
STAFF < FGM
Sensitivity loss
Fs
FsFs
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
II.2 Bz SC1
STAFF
FGM
II.2 Bz SC2
Some differences, as Bperp: Staff < FGM,
Best fit with SC2
Fs
FsFs
Parasite spikes
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
II.3 Bz All S/C
Fs
FsFs
Parasite spikesdifferent on each SC
Parasite spikes different between STAFF and FGM
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
III. Wave Forms comparison
III.1 Filtered Bx,By,Bz, Bperp SC1
STAFF bug, offset NE 0
STAFF/FGM : difference about 0.5 nT
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
III.2 ZOOM on Filtered Bx,By,Bz, SC1
Looks the same, butSTAFF < FGM
About 20% at 2 Hz
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
III.3 ZOOM on Filtered Bx,By,Bz, SC2
Best fit: About 5 %But not everywhere
16
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
IV. Background noise Level IV.1 Bx,By,Bz SC1
Starting Time 09:02:00.029
Starting Time 09:02:00.486
No reliable measurement
Fs
Fs Fs
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
IV. Background noise Level
IV.2 Bz SC1Fs
Fs
No hurried conclusion !Must be re-computed
For other events
FGM - STAFF-SC (from B. Grison)
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
P. Robert, Croos Cal WS, 2006-02-02, ESTEC
PRELIMINARY CONCLUSION
- This work has be done too quickly: We have to take care with too fast conclusions
- Two basic problems has been identified:
a) Why perp DC. Field estimated from STAFF SC1 is less that SC2,3,4 ?
b) Why perp DC field estimated from STAFF is less than FGM measurement ?
. True for perp. DC field,
. But also true on the entire spectra,
. And also true on the filtered waveforms
We have to look on the 4 transfer functions, and carrefully study the onboard calibration
- A large amount of work remain to be done:
a) Study other cases, in other regions of spacein other epochs
With or without strong DC field
b) See if preliminary conclusions remains the same ; see also HBR mode
c) Introduce the new despin utility software, and restart all…
STAFF SC - SA (B. Grison)
10-1
100
101
102
103
104
10-12
10-10
10-8
10-6
10-4
10-2
100
102
104
10-1
100
101
102
103
10410
-10
10-8
10-6
10-4
10-2
100
102
104
106
10-1
100
101
102
103
10410
-10
10-8
10-6
10-4
10-2
100
102
104
106
FGM
STAFF-SC
STAFF-SA
f-2.5
SC 2-FGM/STAFF/EFW/SC+SA 2002/02/18 04:59:28-04:59:48
FGM/STAFF
nT2/Hz
EFW
(mV/m) 2/Hz
Hz
EFW
STAFF sensitivity
Fci=0.38Hz Flh=16Hz
FGM - STAFF - EFW (B. Grison)
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