whats up with this pempro graph

[sungrazer (Karen)]

Hi

Can anyone assist please.

I have downloaded pempro and have a nice graph for the first run which i up loaded to the mount - now this is what i get when i run pempro with the pec on? any ideas?

second graph is what happens further into the collection? it adjusts the pec graphs so it actually looks like that collection was farily good?


cheers
KAREN

[PRejto (Peter)]

I think you are just seeing drift due to polar misalignment. The plot would stay centered along the x axis if you were "perfectly" aligned at dec=0. It looks like the PEC is working. Perhaps use the polar alignment routine in PEMpro.

Peter

[sungrazer (Karen)]

Thanks Peter
I thought that was probably it but the graph I get from phd2 for alignment is pretty good
I'll have another go at it

Cheers
Karen

[stevous67 (Steve M)]

Hello Karen,

Peter is correct, and ideally you should have polar alignment accuracy at 1 arc minute of error or less. Of course, the lower the better. Even at this level, the measurements will still drift, but you can have Pempro adjust the graph so it reports your PE without the drift being reported.

You can see in the help section of Pempro, dift is normal:

http://www.siriusimaging.com/Help/PE.../grapharea.htm

To lock the drift to the one axis, in the "Acquire Tab", check the two boxes

Adjust X for X drift, and
Adjust Y for Y drift

Your RAW data will not be effected.

Steve