Software Bisque Paramount 6 Series - Labeling the Home Position on the Sky Chart

Paramount GEM User Guide
22 | P a g e
• If, after homing is complete, the coordinates of the telescope cross hairs displayed by
TheSky Professional indicate that the mount is pointing anywhere other than hour
angle 0, declination 0, then either TheSky Professional’s location, date, time, or time
zone is not correct, or the mount has not been calibrated properly.
For Paramount’s without on-axis absolute encoders, the mount
must be successfully homed before slewing and tracking are
permitted.
When the Find Home command is issued from the hand controller (by double-tapping the joystick button,
see page 98 for details) or from TheSky Professional (page 108), the mount slews to the home position
which establishes the baseline or “zero point” the control system uses going forward.
Subsequent observing sessions use TheSky Professional’s local sidereal time to determine the mount’s
equatorial coordinates. Make sure the computer’s clock maintains accurate time (page 25).
For mounts not equipped with on-axis absolute encoders, homing provides the following benefits:
• Once a mount is aligned with the celestial pole and homed, repeatable and accurate pointing from
night to night can be achieved using TheSky Professional and the TPoint module.
• After homing, the control system establishes the mechanical orientation of the mount and will
only slew to the software slew limits (see “Mount Slew Limits” on page 146).
• The control system’s periodic error correction (PEC) uses this information to calibrate the internal
PEC table with the orientation of the worm gear.
• The mount’s orientation can be restored after power outages or other communication
malfunctions.
• The home position can be used to help roughly align the polar axis to the celestial pole (see “Rough
Polar Alignment” on page 101).
Labeling the Home Position on the Sky Chart
Calibrating the mount (page 25) on the wrong star or configuring TheSky Professional to use the wrong
location, date, time, or time zone for your location means the Paramount will be “lost in space.” The
telescope cross hairs on the Sky Chart appear at the “wrong” coordinates and the mount does not slew
to the correct coordinates when commanded to do so.
If the coordinates of the telescope cross hairs do not match the actual physical orientation of the
Paramount, or the mount does not slew to the correct coordinates, you will be scratching your head
wondering what is wrong. The next step is to post a support question asking, “Why is my mount pointing
to the wrong coordinates?”
For this reason, Software Bisque recommends creating a permanent text label on the Sky Chart that shows
the location of the mount’s absolute home position (page 136) on the Sky Chart to provide a constant
visual reminder of where the telescope cross hairs must be after successfully finding home.