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General Astronomy => Beginners Forum => Topic started by: Cory Bass on January 16, 2018, 03:28:35 AM

Title: How do various GOTO alignment techniques impact GOTO and tracking performance on
Post by: Cory Bass on January 16, 2018, 03:28:35 AM
Hi everyone,

I've been looking around the internet trying to find an answer to a question I have regarding GOTO equatorial mounts. I own an iOptron SmartEQ Pro with a small, light refractor typically mounted on it. This mount comes with two alignment procedures, a "one star align" and a "multi-star align". The former only uses one star to align the mount, while the latter can use many stars. I believe, in doing my research prior to making my purchase, that many GOTO mounts feature similar routines.

What I would like to know is this: how does the use of one star and multi-star alignment impact GOTO pointing (the ability to accurately slew to and point at a target in the sky) and tracking performance (the ability to keep the target centered in the eye piece)? Or, put another way, how does using more stars impact GOTO and tracking performance? Assume a "normal" amount of polar alignment error for a beginner. My instinct is that the more stars added to the mount's internal pointing model, the more accurate the GOTOs will be. I have no intuition yet on how it would impact tracking, though.

This leads to a few more follow up questions:
What is the purpose of a one star alignment if two (or more) star alignment is naturally better (assuming it is)?
Does the quality of the internal pointing model impact the tracking performance (the ability to stay centered on a target) on a GEM?
Can a high quality pointing model (with, say, six well-centered stars) compensate for less than stellar polar alignment or collimation of the scope and the mount's polar axis? Either w.r.t. GOTO accuracy or tracking performance?