PEMPro Version 3

With PEMPro Version 3 you can now correct your mounts periodic error, polar alignment and backlash using your CCD Camera or Webcam to dramatically improve tracking and guiding.

Here is a link to the Astro Imaging channel that has an extensive discussion of PEMPro with the author.

New Features Summary for Version 3

•Numerous user interface changes to make PEMPro visually more current, easier to used, and more intuitive.

•Support for new cameras and camera control programs including:

  • All cameras with an ASCOM Camera driver
  • Sequence Generator Pro
  • PEMPro-enhanced PHD2 (free download)
  • TheSkyX Camera Add On

•Improved support for cameras and camera control programs previously supported in PEMPro V2:

  • All Cameras supported by MaximDL Pro v4, v5, and v6
  • CCDSoft V5 
  • AstroArt
  • Meade DSI series
  • All video cameras that have standard Direct Show or WDM drivers. 

•The Create PEC curve window has improvements to better select wanted and filter unwanted frequencies.

•A new 3D FFT graph shows frequency/time relationships.

•Numerous user interface improvements have been made to the Polar Alignment Wizard.

•The Backlash exerciser now supports the ASCOM MoveAxis method. 

•One-click PEC automated the whole process of programming periodic error for some mounts (coming soon).

•Programmable API to automate PEMPro (coming soon).

•Programmable API to allow mount vendors to add support for their own mounts (coming soon).

•Polar alignment via Plate Solving (coming soon)


PEC Features

•PEMPro collects and graphically displays periodic error data in real-time.

•Calculates the most accurate periodic error data PEMPro by taking into account camera image scale, camera binning, exposure time, camera rotation, refraction, and star declination.

•Steady skies are not needed. PEMPro fits the periodic error data to an optimized and smoothed curve.

•Perfect polar alignment is not needed. PEMPro can subtract drift from the periodic curves.

•Easy to use Wizards that set up parameters accurately. 

•Uses the main camera to provide more area of the sky than an autoguider to find a suitable star. 

•Natively supports inexpensive webcams and video cameras.

•The Calibration Wizard can slew the telescope to a good sky position, and nudge the scope to find or center a star.

•The Frequency Spectrum graphs can show worm gear fundamentals, giving insight into where in the gear train the periodic errors are coming from.

•Analyzes collected data and creates a smoothed periodic error correction curve. Advanced control features that allow you to tweak the resulting PEC curve.

•Directly uploads a PEC curve to most commonly used mounts.

•For mounts without direct PEC upload, “play back” of the inverse of the periodic error curve for the mount to capture, thus eliminating effects from drift and random seeing conditions that usually happen when an autoguider is used to program PEC.

•Refine a previously created PEC Curve to reduce residual periodic error not removed by the PEC curve.


Polar Alignment Features

•Uses Electronic drift alignment is considered the most accurate polar alignment method.

•Polar Alignment Wizard leads you through the steps to achieve the best possible polar alignment quickly and painlessly.

•Accounts for refraction to produce a more accurate result than other drift alignment methods.

•Automatically selects a suitable star for tracking declination drift.

•A new star is automatically found and used if the star is lost because of the mount alignment change .

•Uses the main camera to provide more area of the sky than an autoguider to find a suitable star.

•Support for video cameras allows you to use an inexpensive webcam.


Other Features

•The Star Finder tab is helpful if you have a small CCD field of view to locate a star or other object when your mount's alignment is not perfect. Press one button to calibrate, then another to start building a spiral mosaic, which is displayed directly on the screen. Once the star you are looking for shows up on the mosaic you can click on it and the scope will slew to it.

•The Backlash Exerciser issues alternating North/South moves to the mount while exposing an image. It allows you to assess the state of backlash of your mount. Too much backlash could result in poor auto-guider performance.

•PEMPro can be used to evaluate unguided tracking accuracy of the next mount you are planning to purchase.

•Online support by experts in mount tracking characteristics is available on the CCDWare PEMPro forum.


(Further information and screen shots will be forthcoming. We wanted to get Version 3 to you as soon as possible.)


Reduce Periodic Error

Accurately Polar Align

Measure Backlash


Improve Your Images


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Online Documentation

Actual Results from Users


Screen Shots



What's new in Version 2

Polar Alignment Wizard
Quickly, accurately, and easily helps you dial in polar alignment.

Backlash Exerciser
Checks the backlash of your mount.

Star Finder
Helpful if you have a small CCD field of view to locate a star or other object when your mount's alignment is not perfect.

Video Interface
Provides a low cost way to use PEMPro using a webcam or inexpensive CCD camera. No extra software is required.