This chapter is meant to be used as a brief guide to coordinating EIT observations and requesting and obtaining EIT data.
The EIT synoptic program is run with the intention of maintaining a daily survey of the state of the sun. The nominal synoptic program consists of full-field images of all four EIT wavelengths. The times of the images, the number of images and their resolution may vary from day to day.
The EIT science planner coordinates the observing sequences which are run in addition to the synoptic data. The SOHO observing targets page sometimes includes EIT subfield target coordinates and areas, image times and wavelengths, and formal observing campaigns. However, these are subject to change, and some information (such as pointing) is not available until the day of the observations, so this page isn't completely accurate. The only way to know for sure is to contact the EIT planner. The email address usually used for planners is firstname.lastname@example.org
The additional observing programs which the planners coordinate are usually comprised of an EIT subfield run at a higher cadence than the full-field images. The JOP 001 movies and this movie of a macrospicule eruption are examples of this type of observation.
There is a separate chapter for the EIT science planners.
The best way (the only way we prefer) to plan an observing program using EIT is to contact the current EIT science planner or (if you already know the date of your proposed observations) the EIT team member who will be science planner during the intended time of the observation. You may want to put together a JOP (Joint Observing Program) if you require the participation of more than one SOHO instrument or if you are planning on coordinating an observation with a different observatory. If you plan on being a JOP leader, you should check with Bernhard Fleck and Piet Martens at email@example.com for information about submitting a JOP proposal and being an effective JOP leader.
Filename Date ExpoTime Wave::Filter Image(blocks) Image Pos(pix) Processing Steps EFR19961003.070157 1996-Oct-03 07:01:57 15 s 284::Clear 2x(16,16) @( 1, 20/1024,1043) Sect Seq::nomask/noocc/rice EFR19961003.070354 1996-Oct-03 07:03:54 1 s 195::Clear 2x(16,16) @( 1, 20/1024,1043) Sect Seq::nomask/noocc/rice EFR19961003.070538 1996-Oct-03 07:05:38 5 s 304::Clear 2x(16,16) @( 1, 20/1024,1043) Sect Seq::nomask/noocc/rice EFR19961003.141016 1996-Oct-03 14:10:16 3 s 171::Clear 1x( 9,14) @( 737, 180/1024, 627) Sect Seq::nomask/noocc/rice EFR19961003.141122 1996-Oct-03 14:11:22 28 s 284::Clear 1x( 9,14) @( 737, 180/1024, 627) Sect Seq::nomask/noocc/rice EFR19961003.141325 1996-Oct-03 14:13:25 7 s 195::Clear 1x( 9,14) @( 737, 180/1024, 627) Sect Seq::nomask/noocc/rice EFR19961003.141434 1996-Oct-03 14:14:34 23 s 304::Clear 1x( 9,14) @( 737, 180/1024, 627) Sect Seq::nomask/noocc/rice EFR19961003.143113 1996-Oct-03 14:31:13 3 s 171::Clear 1x( 9,14) @( 737, 180/1024, 627) Sect Seq::nomask/noocc/rice EFR19961003.143219 1996-Oct-03 14:32:19 60 s 284::Clear 1x( 9,14) @( 737, 180/1024, 627) Sect Seq::nomask/noocc/rice EFR19961003.143421 1996-Oct-03 14:34:21 7 s 195::Clear 1x( 9,14) @( 737, 180/1024, 627) Sect Seq::nomask/noocc/rice EFR19961003.143531 1996-Oct-03 14:35:31 23 s 304::Clear 1x( 9,14) @( 737, 180/1024, 627) Sect Seq::nomask/noocc/rice
Filename: EFR199610003.070157 - 'EFR' stands for "EIT FITS Realtime/Quicklook". The numbers preceding the period denote the date of the observation - yyyymmdd. The numbers following the period are the time of observation (in universal time) - hhmmss. 'EFZ' denotes EIT Fits Level Zero data.
Date: The date is the same as the information in the file name.
ExpoTime: The total exposure time of the image. Exposure times vary for different filters, and for the type of solar activity.
Wave::Filter: 'Wave' denotes one of the four EIT wavelengths - 171, 195, 284, and 304 Å the 'Filter' is usually in the Clear position or in the Aluminum (Al +1) position.
Image(blocks): The number preceding the 'x' is the binning of the image - 2x(16,16) means that the EIT data are binned into sets of 4 pixels (2-by-2) to reduce the size of the image. A 1024 by 1024 pixel image is thus reduced to the size of a 512 by 512 image. The second set of numbers (16x16) is the number of data blocks, with 32 pixels per block.
Image Pos(pix): The EIT pixels comprising the image. (X0,Y0/X1,Y1) A full-field image will run from the first pixel to the 1024th pixel in the x-direction, and the 20th through the 1043rd pixels in the y-direction. A partial image will have a smaller range of pixels, and will consist of a 2-dimensional array of smaller size. The nominal readout pixels are 1 to 1024 in the x-direction and 20 to 1043 in the y-direction. A subfield image listed above is as follows:
EFR19961003.143531 1996-Oct-03 14:35:31 23 s 304::Clear 1x( 9,14) @( 737, 180/1024, 627) Sect Seq::nomask/noocc/riceYou can tell the image is a subfield because its size is 1x(9,14), 9 by 14 full-resolution blocks. The location of these blocks are 737:1024 in the x-direction (the full-res x range is 1:1024, so this subfield is far to the side of a full-resolution image) and 180:627 in the y-direction (the full-res y range is 20:1043, so this subfield is somewhere in the middle).
Note: The level zero data, when available, is more complete than the quicklook data, and the fits headers contain more information. It is usually available about a month after the observing time. You should always try to use level zero data.
Last revised: Tuesday, December 25, 2001 2:20 PM - F. Auchère