Image Information (Photometry)
The Image Information page is a member of
the
Aperture
Photometry Properties dialog. This page shows a table
containing the instrumental Properties used in the photometric
calculations as obtained from the image headers. The table has one
row per image listing the image name, camera gain, readout noise,
exposure time, and other properties determined from the image
header. The table columns can be resized by dragging the vertical
separator bars between the column headings.
Photometry Keyword Properties
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Image
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The name of the image.
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Gain
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The camera gain in units of [electrons per ADU].
This is taken from the GAIN keyword in the image header.
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Noise
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The readout noise, or baseline noise in the camera
image, measured in [electrons]. This is taken from the RDNOISE
keyword in the image header.
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Exp.
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The exposure time of the observation, measured in
[seconds]. This is taken from the value of the EXPTIME keyword in
the image header.
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Airmass
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The airmass of the observation, taken from the
value of the AIRMASS keyword in the image header.
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Filter
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The name of the filter used for the observations.
This is taken from the FILTER keyword in the image header.
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Date
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The date of the image acquisition, taken from the
DATE-OBS keyword in the image header. This is the standard value of
the UT date at the beginning of the exposure.
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Time
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The time of the image acquisition, taken from the
DATE-OBS keyword in the image header. This is the standard value of
the UT time at the beginning of the exposure. For old style, pre
Y2K FITS headers, this value is taken from the TIME-OBS
keyword.
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Editing Image Information
Changing values in the image information table is
simply a matter of clicking on a cell and typing new numbers into
the target cell. Additional tools are provided in a pop-up menu
that is opened by right-clicking on the table. The menu provides
the ability to copy or save data from the table. In addition, if
working with an image set, the menu provides tools for copying
specific cells to other cells of the table.
Note
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The particular commands available in the menu
depend upon whether a single image or an image set is being
measured and whether a single cell or a range of cells is
selected.
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Copying Table Values to Other Cells
The example below shows how to copy cell contents
to other cells of the table. In this example, we wish to copy two
items from the first image (top row) to all of the other images. To
do this, the table must be in "multi-selection" mode, as indicated
by Multi-Selection [on] in the menu
(if the table has multi-selection off, click on the Multi-Selection [Off] item to change its state,
then right-click to re-open the menu).
Copying cells in multi-selection mode
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Click on the cell(s) in the row you wish to
copy.
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Drag the mouse to the final cell to highlight a
copying range. You may also click on the first cell of the range,
then use the standard Windows protocol of holding down
the[Shift] key and clicking on the
last cell of the range.
-
Right-click on the table to open the pop-up
menu.
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In the menu, click the mouse on the Fill... command you wish to use. To copy only the
marked cells, use Fill Down
orFill Up.
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To update the values to the images, click
[Apply] on the dialog.
Changed table values are not saved to the permanent
image files unless you use one of the standard
saving protocols.
Related Topics
Aperture Photometry
Aperture
Photometry Properties
Mira Pro x64 User's Guide, Copyright Ⓒ 2023 Mirametrics, Inc. All
Rights Reserved.
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