- Polar Alignment
Polar alignment is the act of aligning the rotational axis of a telescopes
equatorial mountin parallel with the rotational axis of the earth.
There are various ways to achieve this.
The method to use differ depending on if the alignment is taking place in daylight or in night. Furthermore, the method differs if the alignment is done in the
Northern Hemisphereor Southern Hemisphereand σ. Other things to consider are what the purpose of the alignment is. For example, the demand for accuracy is much more significant in astrophotographythan in occasional stargazing.
Aim at a
σ Octantis the
A rough alignment is performed - then refined by pointing at different stars and observing any drift that occurs. The mount is then adjusted according to the direction of the observed drift.
Equipment used in polar alignment
Crosshair Eyepieceis an ordinary ocular with the only difference that it has a Crosshair for aiming and measurement of the angular distance. This is useful in any type of polar alignment, but specially in drift
Auto guiding systems
Dedicated Polar scope
A small telescope usually with an etched reticle that is inserted into the rotational axis of the mount.
Various problems in alignment
Inertial guidance system
* [http://telescopes.com/faq/Polar-Alignment.html FAQ Polar Alignment]
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