This plot shows the history of the mount tracking and seeing (open loop)errors for both axis X and Y.

This is the error that would happen if auto-guiding is not in effect, known as the open loop error, the one which is expected to be corrected by the auto-guiding.

It is automatically computed by SkyGuide regardless of the auto-guiding status (active guiding or not, and any aggressiveness values).

This means that one can see and compare this open error with the closed loop error resulting of auto-guiding and supposed to be smaller.


By default, the number of iterations displayed in the graph is 50.

To change the plot history length, see advanced settings.

To change the unit of errors, you must change the unit in the information tab.


The mount tracking errors are displayed in black.

The RMS is displayed in blue. The  button in information tab allows to clear the mean and RMS values.


 Plots are cleared when guiding is started. You can manually clear the plots with the  button.


To record the history into a file that can be later on used for analysis, SKG allows to write all Information into a Comma Separated File. Output to CSV can be enabled/disabled while guiding at any time.


By default the scale of the Y axis is automatically adjusted to fit the error values displayed in the plots but sometimes to ease the reading it could be good to use a fixed scale.


The vertical toolbar allows to define how the Y axis will be displayed:

The upper check box allows to fix use the value displayed under Y axis label as a fixed scale.

To change the Y axis scale you must use the slider bellow the Y axis label.

The check box under the -mean label allows to subtract the error mean to the error.

The goal behind the mean subtraction is to remove the constant error caused by the drift from the tracking error to provide a better understanding of the real tracking errors.