Paramount User Guide
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P a g e
As an example of periodic error versus seeing versus image scale, if the mount’s peak to peak periodic
error is two arcseconds, and the local seeing conditions average three arcseconds, then the tracking error
caused periodic error is
less than
the tracking errors caused by seeing conditions, so correcting the
mount’s periodic error is not critical.
However, if the local seeing averages one arcsecond and the optical system’s image scale is one arcsecond
per pixel or smaller, you want to make sure that the periodic error is as small as possible for optimal
results.
TheSkyX Professional Edition
is used to compute, retrieve and save a periodic error correction curve to the
Bisque TCS firmware.
When the
Apply PEC Corrections
checkbox is turned on, the resulting corrected periodic error of the
mount should be less than one arcsecond (usually 1 arcsecond peak to peak error or less), which is
normally less than the errors introduced by local seeing conditions (typically 1-5 arcseconds, depending
on the location, weather conditions, etc.).
Figure 73: The Bisque TCS PEC Table tab on the Periodic Error Correction tab (Bisque TCS window).
Apply PEC Corrections
Turn this checkbox on to apply periodic error corrections during sidereal tracking. Note that periodic error
correction will not be applied when tracking fast moving objects, such as spacecraft.
Bisque TCS PEC Table Tab
The
Bisque TCS PEC Table
tab on the
Periodic Error Correction
tab shows a graph of the mount’s periodic
error correction table. Note that you must first retrieve or
Get
the periodic error table that is stored in
the mount’s firmware. The message
No Table Present
is displayed on the graph if the periodic error data
has not been retrieved from the mount, or the mount does not have a periodic error curve. The green
line on the graph shows the corrections that are applied over one period of the worm. The black vertical
line shows the current position of the worm in the PEC table.
