Tracking Error Graph

The Tracking Error Graph is a graphical presentation of the most recent 1 to 15 minutes of guiding errors. You can choose to display the errors in either or both axes, expressed in either the camera (X–Y) or telescope (RA–Dec) frame of reference. In addition either RMS Trends or markers indicating when corrections were commanded can be displayed. The data can be plotted against time, with the graph auto-scrolling toward the left when it fills up, or as a scatter plot of Y errors against X errors. The vertical scale and time duration of the graph are selectable. The peak excursion and current RMS value of each error are displayed at the bottom of the graph for quick reference.

The Tracking Error Graph window can be adjusted to any desired size using the mouse; the graph automatically stretches or shrinks to fill it.

Tracking errors are always collected whether this window is active or not, so you can turn it on to check for guiding anomalies if you suspect one has occurred based on inspection of a main camera image.

Please note that the graph shows the instantaneous measurements of guider offset, not the actual tracking of the mount itself. If you set the Aggressiveness to a low value, such as 2 to 4, the mount will effectively be following a “rolling average” of the current and recent guider measurements. In that situation, you may see a large scatter on the graph due to seeing, but the actual guiding performance could be several times better than indicated by that scatter. Of course this only works if the “real” errors are slow enough to be tracked out with a low aggressiveness.

All options are selected from the menu at the bottom left corner of the window.