This addon utility for ACP uses the pointing model generated for your mount to enhance its tracking accuracy as well as its pointing accuracy, allowing longer unguided exposures to be achieved, useful for imaging in the field where setting up an extra guide scope is troublesome.
SmartTrackACP will automatically compensate for all of the error parameters modeled by the pointing engine in ACP, including polar misalignment, RA/Dec bias, axes misalignment and tube/mount flexure. It will also correct for the changing atmospheric refraction if you have enabled that in ACP.
It does this by constantly monitoring the difference between the physical coordinates
of the mount and the corrected coordinates those physical coordinates would map
to once the mount model correction has been applied.
If the difference goes over the specified allowable error, ASCOM pulseguide() commands are sent to the mount to correct it’s pointing.
example of the level of correction achievable is shown below. This is
an animation of a pair of 400 second (6.7 minute) test shots through my
10" LX200R SCT, one regular unguided shot, the other also unguided but
The scope has a focal length of 2760mm, giving an image scale of 0.67 arcsec/pixel. The trailing is evident in the unguided image, but greatly reduced by running SmartTrack.
The SmartTrackACP utility relies on the ACP pointing model being accurate enough to calculate small
errors in the mount pointing. In order for this to be true, you need to ensure
it has enough measurement points on each side of the meridian you will be
tracking. I would recommend having at least 30 points on each side of the
meridian, or more if your mount has a large pointing error.
This is easily achieved by using the auto-mapping script in ACP.
Once a sufficiently accurate mount model has been built up, simply slew to
your desired target, set the desired maximum allowable
error in arcsecs and click the “Start SmartTracking” button.
This will change the status line from “Normal Sidereal tracking” to “SmartTrack Tracking” and the current deviation from ideal tracking in RA/DEC will be displayed.
Whenever these errors go above the configured allowable error, a pointing adjustment will be sent to the mount to reduce the error.
To stop the SmartTrack corrections, simply click the button again and the mount will revert to normal Sidereal tracking.
SmartTrackACP detects the mount is slewing, it will suspend making
corrections until the slew completes, after which it will update its
internal target coordinates where it will keep the mount pointing.
SmartTrackACP will also suspend making corrections if it detects that mount tracking is disabled, as happens between plans.
This means you can start SmartTrackACP at the start of your imaging session and leave it running while you image and slew, with no manual intervention required.
· Maximum allowable error in RA/DEC.
v1.0 - Initial release.