removing pairs of alternating corrections within an interval defined by the user.  The 

interval can be selected between 2 and 255 steps, the same units described for shifting the 

PEC playback.  (On a G 11, this corresponds to about 9.6 seconds maximum.)  Any 

alternating corrections made within this interval will be removed from the data.  This 

function can be used multiple times, with a smaller interval at the beginning and larger 

intervals if needed. 

4.3.2.7  Average Data 

Because of random fluctuations in the periodic error and random guiding errors during 

the training run, you can often get more accurate PEC data by averaging the corrections 

from more than one training session.  After the second training run, two independent sets 

of data are available. The latest data trained or calculated is stored in the current data set 

that is used for guiding. Any data that was previously in the current data set is moved into 

the backup set when you perform another training session.  When you select   Average 

Data,   the arithmetic means of the tracking runs is calculated and stored in the current 

data set. The previously used data (the second training run) is saved into the backup set. 

The   Average Data   function is not limited to two runs. During the third training run, 

with the average function used on the previous two, the current data is backed up and 

averaged with the new data.  Once more, the newly averaged data is stored in the current 

data set.  The algorithm that is used to average the data correctly weights the previous 

average so that all individual training runs are equally weighted.  This process can be 

repeated to average up to 255 training runs. 

If the averaging function is not used, newly trained data simply replaces the previous 

training run in the current data set.  The previously averaged data remains available in the 

backup data set, allowing you to ignore bad training runs (those with lower quality 

guiding). 

4.3.2.8  Restore Data 

This function simply copies the data from the backup data set to the current data set.  You 

can use this to overwrite a flawed training run with the previous trained or calculated 

data. 

4.4  Other Functions 

There are two other functions that are especially useful when imaging.  They are: 

TVC

   Helps compensate for the response delay when changing direction in Dec. 

caused by gear backlash. 

Alarm Timer

   Allows you to set alarms to alert you to the end of an exposure 

time. 

Refer to chapter 5 for a complete description of these functions. 

Gemini Users Manual 

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