PrecisionPEC's Main Window

PrecisionPEC is a Windows application that can be used to accurately determine the Paramount ME's periodic error (under virtually any seeing conditions), and then directly update the Paramount ME's internal firmware with the optimal periodic error correction curve for your mount.

 

The main window's controls are described below.

 

 

Image Scale (arcsec/pixel)

Enter the scale of the CCD images produced by your camera's detector and optical system, in arcseconds per pixel. Use TheSky6's Image Link to compute the image scale parameter.

 

Importance of the Image Scale Parameter

The magnitude of the periodic error graphed by PrecisionPEC, in arcseconds, is entirely dependent upon the image scale parameter. Always double-check what you entered for the image scale parameter!

 

Example of a "Bad Image Scale"

 

Let's suppose your mount actually has 3 arcseconds, peak-to-peak, uncorrected periodic error (which is typical).

 

If you incorrectly enter an image scale of 1.00 for an optical system that actually has an image scale of 0.5 arcseconds per pixel, then PrecisionPEC's Fit graph will show your mount's periodic error as 6 arcseconds peak to peak (twice the actual scale).

 

Further, if you were to continue on and upload this incorrect Final Curve to the Paramount ME, then the mount's internal periodic error correction algorithms will be too large (over correcting) by a factor of two!

 

Therefore, in order to get "valid" results, use great care when computing and entering the image scale parameter!

 

 

Encoder resolution (arcsecs)

Specifies the minimum encoder resolution, in arcseconds, of the Paramount ME. This value is "fixed" for all Paramount MEs, and cannot be modified.

 

PEC entries per cycle

Shows the number of "samples" of periodic error data that are used by the control system to create the period error curve.

 

Two Periods

PrecisionPEC, by default, performs a its highly advanced mathematical analysis of periodic error data using one period of the worm. Mark this option to have PrecisionPEC analyze the period error over two periods of the worm. Analyzing the periodic errors over two periods may result in a slightly improved periodic error curve.

 

See Two Period PEC Analysis option for more information.

Show Data Group

 

This group contains options for specifying how the periodic error data is graphed.

 

Raw

Mark this option to view the raw period error data.

 

 

Fitted

Mark this option to view the PrecisionPEC fit curve. Use the Fit command to generate this curve.

 

 

Final

Mark this option to show the graph of the PEC data that can be copied to the control system.

 

 

Zoom Group

 

X

Click the up arrow to increase the maximum value for the x-axis. Click the down arrow to decrease the maximum value for the x-axis.

 

Y

Click the up arrow to decrease the maximum amplitude of the y-axis. Click the down arrow to increase the maximum amplitude.

 

Auto

Click this button to automatically scale the x and y axes to fit the current periodic error data.

 

Plus X Relay Direction Group

 

Auto

Click this button to launch TheSky6 and CCDSoft, and determine the direction of the +X Relay by activating the camera's +X relay and comparing the telescope's before and after coordinates.

 

Note: You must enable relays in CCDSoft for the Auto button to function properly. (Typically, relays are disabled in CCDSoft prior to collecting tracking data.

 

West

Mark this option if the +X relay moves the mount west.

 

East

Mark this option if the +X relay moves the mount east.

 

Data Points Text

Displays the number of autoguider corrections that are in the autoguider log file.

 

Raw Data Sets Loaded Text

Displays the number of Log files that are currently being displayed.

 

Index At Time Zero Text

Displays the value of the Paramount ME's internal motor index when the autoguider data was collected. This value is used to set the phase offset for the fitted periodic error curve that is saved in the Paramount ME control system.

 

Paramount Group

 

This group allows you to specify which mount you own. This setting is critical for using the correct gear ratio (and harmonics) for your periodic error data.

 

ME

Mark this option if you own the Paramount ME Robotic Telescope System.

 

GT-1100S

Mark this option if you own the Paramount GT-1100S Robotic Telescope System.

 

Auto

Click this button to attempt to automatically determine which mount you own (if you're not sure).

 

Graph of Periodic Error Group

 

The Graph of Periodic Error shows three different graphs of the autoguiding data.

 

I. Graph showing Raw Data.

 

 

II. Graph showing Raw Data and the Fit periodic error curve.

 

 

III. Graph showing the Final periodic error curve.

 

 

This is the "data" that is uploaded into the Paramount ME firmware's PEC table, and is used to correct the mount's periodic error during tracking.

 

Data Points

Displays the number of individual tracking log corrections in the Autoguiding Log file.

 

Raw Data Sets Loaded

Displays the number of separate tracking log "runs" in the Autoguiding Log file.

 

Index at Time Zero

Displays the mount's periodic error correction curve index number at the beginning of the tracking log. This value is used internally by PrecisionPEC, and is only useful for debugging purposes.