Fine‐Tuning Polar Alignment - Eyeke2/phd2.planetary GitHub Wiki

While starting planetary autoguiding with rough polar alignment is feasible, we highly recommend fine-tuning your polar alignment (PA) for the best possible autoguiding quality. Here's how you can refine your PA using the Guiding Assistant (GA) tool in PHD2:

Initial Setup: Begin with a rough polar alignment.

Use Guiding Assistant: Activate the GA tool in PHD2 to assess your current alignment's RA and DEC drift slopes.

Adjust Mount: Slightly adjust your mount's altitude (ALT) and azimuth (AZ) knobs based on the GA's feedback. Note whether turning the knobs clockwise (CW) or counterclockwise (CCW) improves or worsens the slopes. Don't adjust ALT/AZ knobs while GA is active; adjust single knob at a time.

Iterate for Perfection: Aim to make the RA and DEC drift slopes as horizontal as possible through repeated adjustments and GA checks. Each iteration should take about a minute.

Early Start: Starting this process early in your setup routine can significantly enhance the autoguiding performance for your session. By refining your polar alignment, you not only improve the accuracy of autoguiding but also the overall quality of your imaging work.

The goal of repeated GA iterations is to reduce both the RA and DEC Drift Rates (marked by red) as much as possible and therefore to reduce slopes of RA and Dec trendlines in the History graph as shown in figure above. Make sure to enable Trendlines checkbox in the History Graph at its left side.