Set Home Posit.

Each of the above Mount Parameters are discussed in detail below: 

5.3.10.2.1  Tracking Speed 

 This menu item allows you to set the speed and method used to track objects in the sky.  

You can select any of the following tracking speeds: 

Sidereal 

Lunar 

Solar 

Adaptive King 

None/Terrestrial 

Closed Loop 

Comet/User Def. 

Train Tracking 

 Calculate Rates 

 Activate 

"Sidereal" speed causes the telescope to track in right ascension (RA) at the rate of the 

Earth's rotation.  It is therefore an accurate tracking rate for stars and other deep space 

objects. 

"Lunar" speed causes the telescope to track the right ascension component of the lunar 

trajectory.  Since the Moon has a non circular orbit and moves in both RA and Dec. 

relative to Earth, "Lunar" tracking speed is calculated for the apparent movement of the 

Moon within the next hour. Especially if the Moon is near the horizon, reselecting Lunar 

tracking speed a while later will result in a slightly different tracking speed because 

refraction and parallax play a large role.  

"Solar" speed is very close to sidereal speed, but slightly more accurate for observing the 

Sun.  It is, however, so close, that visual observers of the Sun can usually use sidereal 

speed without difficulty.  As with   Lunar   tracking,   Solar   speed takes into account the 

changes caused by the elliptic orbit of the Earth, and adapts the tracking rate accordingly. 

"Adaptive King" speed is an enhancement of the fixed King Rate.  Its purpose is to take 

refraction into account when observing near the horizon, thereby adapting the tracking 

rate for the apparent change in an object 

s position.  See Chapter 3, section 3.3.1.2 of this 

manual for a more complete explanation. 

"None/Terrestrial" stops all telescope tracking.  It can be used for terrestrial observing, or 

when it is desirable to stop the telescope from moving without powering Gemini off. 

"Closed Loop" tracking is a tool for keeping an object centered in the field of view (1) 

when the mount is not accurately polar aligned or (2) when an object moves slowly with 

respect to the background sky, and its coordinates are downloaded cyclically.  Gemini 

Gemini Users Manual 

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