SOHO Extreme ultraviolet Imaging Telescope (EIT)
The SOHO Extreme ultraviolet Imaging Telescope
brought to you by
End of SOHO EIT CME watch observations
At the end of 2010 July, SOHO's
Extreme ultraviolet Imaging Telescope (EIT)
will complete fourteen and a half years of synoptic observations
of the low corona. SDO AIA images at much higher resolution and time cadence
are now available for all the EIT wavebands, and three other EUV wavelengths
as well. The telemetry bandwidth that has been used by EIT will be used by
LASCO to improve the cadence of its observations of the fastest CME's. EIT
will continue to obtain a couple of "synoptic sets" of images in all four
wavelengths per day to track detector behavior, and to maintain the uniform
data set. This, and other changes in SOHO instrument operations, are part
of the transition to the "Bogart" phase of the SOHO mission — designed
to get the maximum science out of the mission at the minimum cost to NASA's
shrinking Heliophysics Mission Operations and Data Analysis
(MO&DA) budget.
EIT data will continue to be available via the
Virtual Solar Observatory and
via the older EIT
Web catalog interface.
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New EIT synoptic charts
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An EIT campaign of high cadence observations in shutterless readout mode
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EIT observations in support of the total solar eclipses
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Web access to EIT images and FITS files
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EIT calibration rocket
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EIT 195 Å movies of a disk CME
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EIT 195 Å/171 Å temperature diagnostic maps
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EIT Observing Targets
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EIT Science Topics
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Current Solar Images
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EIT Observing Programs
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What EIT is Designed to Do
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The Instrument
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Response: Updated Daily
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Response: EIT CCD bakeout history
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EIT detector response to SEP events
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Engineering: EIT Temperature Plots
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Engineering: LASCO OBE software load history
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Data Rights Policy
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Science Planning Schedule
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EIT User's Handbook
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Operations Team
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SDAC Home
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SOHO Home |
EIT User's Handbook , EIT Calibration, EIT software updates
occur on December 10, 2001.
Accessing EIT data
If you want GIF images of EIT data....
You can find both
If you want EIT data for quantitative research....
The following procedure should be followed to obtain the EIT data in FITS
format:
- Determine which EIT data are available to support your study. An
EIT team member can provide assistance throughout the whole process
of obtaining data. To generate a list of available data, access the
EIT WWW catalog interface or the
Virtual Solar Observatory. The web
catalog interface will provide a list and brief description of the
data obtained over a range of dates. Keep in mind that the synoptic
data and full-field images can also complement a study, so your data
request needn't be restricted to a specific field of view or time
cadence.
- Note that using the Web interface, you can now download compressed tar
files of the EIT FITS files
As a matter of courtesy, we ask that you send a preprint of any work involving
EIT data to the EIT P.I., and
after acceptance, a reprint to the EIT reprint library, care of
Joe Gurman.
EIT shutterless
program
The EIT group in the solar Physics Group at the
Royal Observatory of Belgium is
conducting a synoptic observing
campaign using the high-cadence capability of the EIT instrument when run in
shutterless readout mode. The latest running of the shutterless program
results are available here.
EIT Shutterless campaign, [Run #38] 2010 January 7 Seg 1 Preliminary Results
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2010 January 7th
19:00 - 22:00 UT
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EIT Shutterless campaign, [Run #38] 2010 January 14 Seg 2 Preliminary Results
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2010 January 14th
19:00 - 22:30 UT
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For Archived Shutterless information, data, and movies; see The ROB High Cadence Pages
EIT and Eclipses
EIT Calibration Rocket results
| The NRL/CSL/IAS EIT rocket flight to help calibrate the SOHO
EIT was launched and recovered
successfully on Thursday, 1997 October 16. Preliminary results indicate
that, aside from a small light leak in the Fe XV 284 Å channel,
the flight was fully successful. Exposure times and detector performance
appear to have been nominal.
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Click on the thumbnail image on the left to access the NRL EIT
calroc page.
EIT Fe XII Å observations of disk coronal mass ejection
and Moreton wave, 1999 July 19
Movies of a flare-related wave and dimming indicative of a possible
earthward-directed coronal mass ejection (CME).
GIF movie | Difference GIF movie
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| 1999 July 19 00:00 - 03:36 UT
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EIT Fe XII Å observations of Solar Tornado, 1998 April 20
Movies of a helical field structure untwisting during a coronal mass
ejection (CME).
MPEG Movie | QuickTime Movie | Time
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| 1998 April 20 08:11 - 11:02 UT
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Maps of the temperature-sensitive ratio (Fe XII 195 Å/
Fe IX, X 171 Å)
The ratio is sensitive over the range 0.9 MK < Te
< 1.5 MK.
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Ratio from 1997 December 6 07:00 - 07:12 UT images
| Ratio from 1997 December 7 07:00 - 07:12 UT images
| Ratio from 1997 December 8 07:00 - 07:12 UT images
| Ratio from 1997 December 9 07:00 - 07:12 UT images
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Ratio from 1997 December 10 13:00 - 13:12 UT images
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Click on the thumbnail image for a full-resolution ratio map.
Older EIT movies
EIT movies from earlier observing sequences can be found on the new
Cinema EIT page.
OBE history
A table showing
when the OBE was loaded with new (or reloaded with older) software loads,
and a partial listing of the new features introduced in those loads.
EIT synoptic maps
EIT synoptic maps
in all four wavelengths in both GIF and FITS format are now available,
courtesy of Elena Benevolenskaya at Stanford U. These include only central
meridional charts.
Additional EIT synoptic charts may be found at the NRL
EIT/LASCO
synoptic maps site
EIT observing plan for tomorrow
The SOHO observing
plan for tomorrow includes EIT subfield target coordinates and areas,
image times and wavelengths, and formal observing campaigns.
EIT science topics
At its 1996 March meeting, the
EIT
Consortium decided to list some initial research topics as well as
volunteers from the consortium to lead the initial efforts in each area.
These are not meant to be exclusive or to indicate permanent rights
of any sort, but it would benefit any prospective Guest Investigator (official
or otherwise) to contact one of the Consortium members whose names are
associated with a topic of interest to the Guest Investigator. The list can be
thought of as the initial framework for the EIT Bulletin Board of proposed
research.
Go to the EIT science topics list.
Current solar images from EIT
The image on the left was obtained in the Fe XII emission line at 195 Å,
while that on the right was obtained in He II 304 Å. Fe XII (eleven-times
ionized Fe) is common at temperatures of 1.5 million K; He II is formed
primarily at 60,000 - 80,000 K.
The times at which these images were obtained are available on the SDAC
"current
solar images" page.
While the pixel scale of the EIT instrument is
1024 x 1024 2.6-arc second pixels, the images to which these thumbnails are
linked has been reduced to 512 x 512 to keep the file size reasonable (160 -
200 Kbyte).
Full resolution GIF representations of EIT images can be found
here.
The LASCO/EIT observing program
The two-month-long EIT and
LASCO interim synoptic program, which began 1996
May 14, ended July 16 with the modification of the on-board software.
The interim synoptic schedule decribes the
former LASCO C1, C2, C3 and EIT "time slots" in the daily plan. The
current observing schedule is much more flexible and varied, and can be
obtained by checking either the
SOHO daily
targets page or the
SOHO
Daily Operations Database.
What EIT is designed to do
The SOHO EIT is able
to image the solar transition region and inner corona in four, selected
bandpasses in the extreme ultraviolet (EUV):
- Fe IX/X, 171 Å
- Fe XII, 195 Å
- Fe XV, 284 Å
- He II, 304 Å
Using either full-disk or subfield images, the EIT can image active regions,
filaments and prominences, coronal holes, coronal "bright points," polar
plumes, and a variety of other solar features. The instrument was designed to
be used in conjunction with other
SOHO
instruments, particularly the
LASCO visible-light coronagraphs and the
SUMER and
CDS imaging spectrographs, as well as with ground-based instruments.
![[image of SOHO EIT telescope
without thermal insulation]](images/EIT_instrument.gif)
The EIT is a normal-incidence, multilayer telescope of novel design.
A paper describing the instrument (Delaboudinière et al. 1996,
Solar Physics 162, 291) is available in
dvi,
PostScript,
or Adobe pdf
form.
The EIT First Results paper
(Moses et al. 1997,
Solar Physics 175, 571) is available at
EIT First Results
The Preflight Photometric Calibration of EIT
(Dere et al. 2000, Solar Physics 195,
13) is available at EIT Calibration
Response: updated daily
The mean counts per unit time in full-field EIT images in each of the four
sectors are plotted from the beginning of operations. Note that 304 Å
appears to show the greatest change with time, and with bakeout.
A table listing the times of our CCD bakeouts is given in:
EIT CCD bakeout history
| An image of the ratio of post- and pre-bakeout calibration lamp
images from the 2000 February bakeout. Most of the enhancement
occurs in the activity belts, where EUV-bright active regions
appear on the E limb, rotate across the disk, and spend a few
days on the W limb.
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| Image of the ratio of post- to pre-bakeout calibration lamp
images from the 2004 September - October bakeout. Note
the now narrower activity belts, closer to the solar equator than
in 2002, and the lack of enhancement at the poles, due to the
return of polar coronal holes to visible latitudes.
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Plots are available for:
The proton storm of 1997 November 6 - 10
Statistics on the EIT detector's response to the energetic proton event
following the X9 flare of 1997 November 6 are available.
Engineering: EIT temperature plots
The most recent plots of:
The EIT Consortium has released its data rights
policy to clarify when and how access to EIT data will be available to
non-Consortium members.
At the 1996 March meeting of the EIT Consortium, the Consortium members
agreed on a data rights policy to encourage
the "widest possible access to and analysis of the EIT data consonant with the
rights of the team members whose dedication and expertise made the instrument
a reality."
EIT science planning schedule
EIT science planners serve for four weeks (plus a few days). We have a
tentative schedule for the next
several months.
The EIT Operations Team at NASA Goddard Space Flight Center
Send mail to:
The SDAC home page
The SOHO home page
Web curator:
Joseph B. Gurman
Responsible NASA official:
Joseph B. Gurman,
Facility Scientist, Solar Data Analysis Center
![[e-mail address: gurman<at>gsfc<dot>nasa<gov>]](https://webarchive.library.unt.edu/web/20130214231127im_/http://umbra.nascom.nasa.gov/local_icons/gurman_email.gif)
+1 301 286-4767
NASA Goddard Space Flight Center
Solar Physics Branch / Code 682
Greenbelt, MD 20771
Last revised 2010 July 14 - J.B. Gurman