STAFFSC FGM Comparison CrossCalibration Workshop ESTEC Noordwijk 2
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 IV. Noise Level Conclusions
A. Old comparisons (IC, London, February 2001) A. 1 Spectrogram Original FGM High res. Files provided by M. Dunlop Already STFF-FGM difference on perp. DC field P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
A. Old comparisons (IC, London, February 2001) A. 2 Average Spectra Original FGM High res. Files provided by M. Dunlop Rather good agreement Between STFF-FGM Sensitivity differs beyond 1 Hz P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
B. New comparisons (February 2006) All following result has done with FGM high res. Data Provided by FGM Dapclus software, using cal tables downloaded from I. C. P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC I. Spectrograms comparison I. 1 Bx, By, Bz SC 1 Rest of spin effect, OK OK
Position in space 18: 00 24: 00 21: 00 22: 00 Tetrahedron size about 1200 km P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC I. 2 Bz ALL S/C OK Pb !
I. 3 Bperp ALL S/C FGM 1) STAFF < FGM, 2) STAFF Pb on S/C # 1 STAFF Sometimes up to 20% When strong DC field P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
I. 3 Bperp SC 1 and SC 2 1) STAFF < FGM, Diff=1 n. T or 16% on SC 1, Diff=0. 5 n. T or 8% on SC 2 FGM 2) STAFF Pb on S/C # 1 Sometimes up to 20% When strong DC field STAFF P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC II. Average spectra comparison Fs II. 1 Bx, By, Bz SC 1 STAFF FGM STAFF < FGM Sensitivity loss Fs Fs
II. 2 Bz SC 1 Fs II. 2 Bz SC 2 Some differences, as Bperp: Staff < FGM, Best fit with SC 2 FGM STAFF Fs Parasite spikes Fs P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC II. 3 Bz All S/C Parasite spikes different between STAFF and FGM Parasite spikes different on each SC Fs Fs Fs
III. Wave Forms comparison III. 1 Filtered Bx, By, Bz, Bperp SC 1 STAFF bug, offset NE 0 STAFF/FGM : difference about 0. 5 n. T P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
III. 2 ZOOM on Filtered Bx, By, Bz, SC 1 Looks the same, but STAFF < FGM About 20% at 2 Hz P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
III. 3 ZOOM on Filtered Bx, By, Bz, SC 2 Best fit: About 5 % But not everywhere P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
IV. Background noise Level Starting Time 09: 02: 00. 486 Fs IV. 1 Bx, By, Bz SC 1 Starting Time 09: 02: 00. 029 No reliable measurement Fs Fs 16 P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
IV. Background noise Level Fs IV. 2 Bz SC 1 No hurried conclusion ! Must be re-computed For other events Fs P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
FGM - STAFF-SC (from B. Grison) 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 SC 1 is less that SC 2, 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 space in 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… P. Robert, Croos Cal WS, 2006 -02 -02, ESTEC
STAFF SC - SA (B. Grison)
FGM - STAFF - EFW (B. Grison)
- Slides: 21