Speckle images

Take a speckle image

This is an experimental feature.

A speckle image can be used to take images of double stars or other bright objects.
The shutter is opened, after about 30 ms some lines (height of the sub array) of the CCD are read out line by line, all lines will be stored, then the next sub array is exposed and so on
The difference to a sub array image is, that there can be taken much more sub arrays in a speckle image
The time to read out the lines is longer than to dump the lines, so there will be more streaking in the image, but this streaking can be removed.
The tracking of the telescope is on.
The Ethernet interface should not be used for speckle images.
Use the tracking CCD, place the object you want to expose, near the right side of the image .
There should not be any other bright objects at the same columns.
Chose Camera - Settings menu.
Declination, Focal Length, Sidereal Rate no entries required for this kind of imaging.
CCD - imaging CCD or tracking CCD, use the tracking CCD, the time to shift the lines is shorter, so there should be less streaking in the image.
Binning - 1 x 1 binning in most cases to get a high resolution, other binning modes may be also possible.
Planetary mode - Use the planetary mode to get a higher read out speed and less streaking.
Focus (check Box) - not checked
Light or dark frame - light frame
Auto Grab number of images - 1 or more
Brake during taking an image - enabled or disabled or ESC key
Esc key or disabled are only available when using Windows 95,98 or Me.
At the bottom of the form at the left there is a Page Control
Chose the Speckle Tab Sheet
Time per line - using the tracking CCD about 0.0015 sec per line, make some tests
Number of lines to read - about 10000 or more
Store first to memory - should be checked
Exposure Time per Sub Array - should be about 0.03 s
Height Sub Array - depends on the size of the object, for double stars about 10
After checking all entries, leave this form.
Then chose: Camera - Take Speckle image.
It is asked for the file name and the exposure is started.