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Re: How to train PEC

 

Comments...

1. You don't need any PC connection, per se, to run the Gemini PEC recorder.? You could use an autoguider camera and the ST4 port to do it I suppose.

2. If you are looking at PHD2 on your PC,? and you can use its Manual guide to move your mount (remember Gemini must be set to Guide mode or easiest to select "G" on the Gemini.net applet) then your mount is getting pulse commands from the Ascom system. (You had to install ASCOM first and the Gemini.net driver).??

In that Gemini.net driver, I think is how you either select the Serial port, or ethernet connection method.

Anyway... play around and you will find a way. ...!

Have fun,
Michael?





On Nov 26, 2017 8:26 AM, "yh@... [Losmandy_users]" <Losmandy_users@...> wrote:
?

>?I think the big question is what is PEC for? It is my view that it is there to get you better unguided exposures.


I know this is a frequent subject for debates, but proper PEC programming does help prevent tracking errors before they happen. This results in better guided or unguided performance. An autoguider can only correct errors after they have occurred, PEC can correct them so they never happen.

If you want to compare PEC to PPEC, there may still be benefits, although these may be fewer
  • For one thing, PEC operates internally to Gemini. The corrections are not only precise, they are instantaneous, not subject to communications delays and PC timing like the corrections from PPEC

  • Gemini keeps track of the worm index position through encoders, allowing existing PEC to be used immediately after slews and goto's -- PPEC has to be relearned after a slew

  • PEC software allows many cycles to be used and programmed, filtering out a lot of the random errors that PPEC might not. Since PEC doesn't have to be relearned after each slew, dedicating an hour or two to training PEC can pay off big dividends over many months of imaging

  • Some PEC software (f.i., PemPro) has built-in knowledge about various gears and error cycles particular to each mount type. This allows PEC curve to be fine-tuned very easily to fix issues specific to a mount. PPEC doesn't do that. I believe an upcoming version of PemPro will even correct errors that occur over multiple worm cycles.?
PPEC is a great tool, but generally it's not better than PEC for both, guided or unguided exposures. In fact, PHD2 team recommends to train PEC before using PPEC if your mount allows it. Perhaps that's the best of both worlds: PEC correcting most of the errors, and PPEC picking up any small uncorrected errors that remain.

Regards,

? ? -Paul
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