Too few guiding corrections

bigbanger

I've been having good nights and bad nights with ASIAIR's guiding. Tonight was a bad night. Have a look at this graph. 2 questions immediately come to mind.

1) Why so few corrections (7 for RA and 1 for Dec) when guiding was often showing 2-3 arc second and beyond deviations?

2) While the (few) corrections where certainly called for why was the one I've circled needed? It was made at a moment when a correction was not needed.

When I ran with the standalone version of PHD 2 it made so many corrections (in accordance with your aggressiveness settings) that you could specify a minimum deviation, below which PHD would avoid making a correction.

BTW, I'm running Beta version 6.71 on an ASI Pro.

w7ay

>> 2) While the (few) corrections where certainly called for why was the one I've circled needed? It was made at a moment when

>> a correction was not needed.

I have noticed that ASIAIR's graphs have different time offsets for the pulses vs what it plots as tracking error (for many versions now). I think the RA pulse that you have circled belongs to the triangular negative RA error that is one or two samples to the right of the RA correction pulse.

(No, the is not predicting the future; the other curve is just delayed :-) :-).

As you have mentioned, if you want more (and smaller) pulses, you will need to change the PHD2 MinMo (minimum movement) parameter, which is not exposed in the ASIAIR user interface. In your case, ASIAIR's guiding ends up being more granular than what you can get from the complete PHD2.

Chen