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CCD Control Window: Top Level
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The top level of the GUI allows one to set various detector parameters
in advance, and to control exposures. Parameters are briefly described
here. Commands for controlling exposures -- start, pause, stop, and
abort -- are self explanatory.
Saved Setup Parameters are stored as one of ten
"saved setups." Current parameters automatically become whichever
saved setup is selected at the time. Saved setups may be named on the
2nd level.
Exposure time Zero-second exposures and fractional
seconds are allowed. Note that for short exposures shutter fly time
errors can become significant. The "Update" button allows one to
change the exposure time of the exposure in progress. E.g. you start a
1200s exposure, but if you decide more exposure time is necessary, you
may enter the new total exposure time and press "Update". You may also
choose to do a shorter exposure this way as long as the new exposure
time is longer than the current elapsed exposure time. When there is no
exposure in progress the "Update" button will be greyed out and unusable.
CCD Window This is the amount of the CCD which is
actually read out. Smaller windows read out more quickly. The window
size may be defined graphically from the image display, or by entering
the number of rows, number of columns, and origin of the readout
region. To define a window from the image display, type "b" in the
image display window, then use the mouse to click on the first corner
of the box, then click again on the opposite corner of the desired
region. Once the desired region is selected, click on the "From
Display" button. To readout the entire CCD, click the "Whole CCD"
button. Note, there is currently a bug in the image display software
includes the overscan region as part of the image when defining a region
from a box drawn on the display. Thus, your region will be off by
32 columns, the width of the overscan region. We hope to fix this problem
in the near future.
Shutter Open for normal exposures, closed for darks
and bias frames. If the shutter will be closed for a dark exposure, the
Closed label will be highlighted orange and an orange border will be on
the Expose button.
Binning The Hamilton is generally used binned 1x1 for normal
observations. However, each axis may be independently binned by 1, 2,
or 4 as data acquisition requires.
Read Speed Fast is about half the time of slow for
dewar #8, gained at the price of increased readnoise (see CCD Characteristics).
Observation Number and Recording The observation
number increments with each recorded exposure. It can be set manually,
but be careful, it is possible to overwrite existing data by setting
the number back. Note that the last unrecorded exposure is saved in
/scratch/hamcat/scr.fits or /scratch/hamshane/scr.fits, for the CAT or
Shane telescopes, respectively. More on recording images in "2nd
Level," below. When set to "Don't Record", the Don't Record label
will be highlighted red and a red border will appear around the
"Expose" button as a warning.
Object The string entered will appear as the OBJECT card
in the image's FITS header. |
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CCD Control Window: 2nd Level
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The 2nd level GUI presents parameters that are usually only set once
in the course of a night, if at all. Only a few of these are for
observer use. MPP and Amplifier selection should remain as set by
default, unless there is a clearly understood reason to change them.
Saved Setup name This allows a name to be associated with a
saved setup (see Top Level).
Record count Whether an image is recorded or not is controlled
from the Top Level by turning recording on or off. The "record count" parameter
is generally set to "1" or "-1" so that all images are saved whenever recording
is turned on.
Directory This parameter should be set to
"/data/shane" or "/data/cat" for the Shane or CAT telescopes,
respectively, so that recorded images are saved in the proper /data
subdirectory on dusty. The data paths from the user computers
in the control rooms are /data/hamshane/ and /data/hamcat/. Please do
not change this parameter, it is important to save them there so that
they will be found and saved in our on-line data archive, http://mthamilton.ucolick.org/data/. Data become available in the archive shortly after being acquired. If
you need to set or reset your data archive password, please
contact a Support Astronomer. If data from a previous observer's
run is in the data directory, contact a Support Astronomer or
Telescope Technician so they can check that the data were properly
archived before clearing the directory.
Root The string entered here becomes the root of the
image file names, prepended to a unique image number. E.g., using the
parameters shown here, the first recorded image will become
/data/hamshane/d1.fits, the second d2.fits, and so on. The root can be whatever
you wish, but we recommend that you use the default "d".
Suffix You may choose the suffix to be appended to
your image file names, but it must be one recognized by our automatic
archiver: fits, ccd, fts, spr, or sdt. We prefer that you use fits as
the suffix for Hamilton data.
Observer's name You may enter any number of first or
last names up to a total of 64 characters. White space and comma
separation are permitted. The string will appear in the "OBSERVER"
field of the FITS header.
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