This page (revision-828) was last changed on 03-Feb-2017 10:35 by Denver

This page was created on 04-Feb-2009 11:25 by David R Williams

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Version Date Modified Size Author Changes ... Change note
828 03-Feb-2017 10:35 18 KB Denver to previous The line's engaged cena anafranilu Minter is now trying his hand at headhunting

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TeamXRTSOTJointMeetingMar09
TeamXRTSOTJointMeetingMar09

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At line 113 removed 3 lines
!SOT/FPP Instrument Status (Ted Tarbell)
!Data reduction & products
!Resulting physics information
At line 114 added 2 lines
!SOT Instrument
*BFI Characteristics ''is a great slide -- it explained a lot of the physics SOT was intended for.''
At line 117 added 75 lines
*NFI
Na I D shows very little difference from the Fe I magnetograms
6300 Å now has a degraded blocking filter that means it can't be used. Shame, because it's used by the SP.
*SP
Spatial resolution shows magnetic elements with res down to 150 km. Not as good as some ground-based, but SOT gets this continually, rather than once or twice a year.
Spatial stability is good to about 0.01 arcsec RMS. CT works at around 840 Hz!
Focus stabiilty of the telescope -- telescope is continually shrinking so focus is changing but hasn't yet stabilised.
Focus stability during eclipse season isn't very good: you have a sort of 10-step shift. If you need absolute highest resolution, do it outside eclipse season.
EDL: Do you use a thicker slit in eclipse season?
TB: No - same slit.
You're not completely out of focus and can't see granulation, but you can still see the magnetic elements.
There is chromatic aberration - when you want to request NFI and SP, say which is your *primary* one.
The things I'm saying about resolution are non-summed. But if you sum on the camera, 2x2, then the defocus is much less important. Especially in the Ca II, this is quite common.
BFI Filter throughput decrease:
The loss isn't that great and can just increase the exposure time.
SOT NFI is down to 40 or so percent for Fe I 6302.5, but Na I D magnetograms at 589 are unaffected due to the other coating.
Current situation is that there is NO bubble in the NFI. And so we can now tune the filter back and forth!!
* 8 seconds or so to tune between lines. THe maximum cadence is about 8 seconds between
ZnS coating on the H-alpha blocking filter means that it isn't routinely used, unless there's a special reason: AR, off-limb, key filament observations for a few hours.
Karin: I used to see fringes
TB: Yeah, but now the flat-fields take it out.
September-October and February-March are when the orbital Doppler shifts are minimal, so optimal for Dopplergram velocity.
EVen from relatively wimpish flux emergence in SOT, you can see very bright points in the corona with XRT.
Shine or Berger can do cork-maps to do LCT on granules and get a horizontal velocity field.
SST with the same analaysis... with a 1m telescope, you can get a mich higher resolution with much more regularity.
Ca II H at the limb: 1.6 second cadence. We believe we are now capturing the dynamics in spicules! Including what appear to be rotational motions.
They have standard data products for off-limb prominences
H-alpha dopplergrams, too.
Full SP takes about 3 hours in most sensitive 'normal' mode. Doesn't have the resolution of the FG: about a factor 2 worse.
FG suffers from Zeeman saturation when the spectral line moves out of the passband of the FG. But in the SP, this doesn't happen and you do get accurate data.
In L2 total polarisation maps, you can sometimes see very weak, fuzzy emission which indicates horizontal field emerging! Very sensitive.
Lites: No crosstalk between I,Q,U & V -- this is the BEST calibrated polarisation instrument known.
Planning: new calendar on Google:
hinode.chiefobs@gmail.com calendar is editable by some people. PWD hatsuhinode lets you see it. Different HOPs have different colours. There are also calendars for instrument events. Have scheduled in the meetings.
Give it a try!
KPD: do you have any problems with pointing or keeping on a target in eclipse season? It doesn't look like it.
TB: It's enough so that if you were to try to overlay a raw SOT images onto an XRT image, it would be offset.
Shimizu-san has made a database online which allows correction of that to about 5 arcsec.
KPD: so outside eclipse season we should be able to do this quite well
DHB: there is a drift between SOT and EIS: what is that?
TB: That's the correlation tracker at work, and getting all the information together to work that out is challenging.
EDL: Do the data exist to complement the cork studies?
TB: would be good to ask Shine if he wants to go up higher into the atmosphere.
Karin: You can take out the slit motions in Y but how about in X?
TB: Actually this is only happening after the slit, on the Littrow, so it can't change the X position of the slit.
This page (revision-828) was last changed on 03-Feb-2017 10:35 by DenverTop