Meade LX200 instruction manual Toc c. Unknown Site, Toc d. Which Alignment Method To Use?

Meade Instruments Corporation - Meade LX200 Instruction Manuals

stars that are not too close together–try to use stars that are at least 90° apart. Do not use Polaris as one of the stars because RA changes very fast at the Pole and minor centering errors can translate to large RA pointing errors. Also, avoid stars near the zenith (straight up) since azimuth changes very fast in this area. Generally speaking, choosing two stars as far apart as possible will yield very accurate pointing.

[ toc ] c. Unknown SITE

To use the LX200 telescope at an unknown location, use the following procedure:

(1)Select site #5 (UNKNOWN) from the SITE menu. (Note: This site cannot be edited like site numbers 1-4 as described on steps 4-10.)

(2)Follow the Keypad display prompts to select and center the two alignment stars.

As described above, the LX200 will check the accuracy of the two stars and give the "Align Mismatch - Check Stars" message if it detects an error.

[ toc ] d. Which Alignment Method To Use?

Each of the three methods described above have advantages and disadvantages. The following table summarizes these properties.

		Atmospheric	Atmospheric
	Pointing Accuracy		Refraction
		Refracting		When Best Used
	Determined By:	Correction*	Correction
			Determined By:
				Best used when the
1-Star Known	Level of			telescope is
		Yes	Level of Telescope	permanently
SITE	Telescope
				mounted and
				accurately leveled.
				Best used on a
2-Star: Known				transportable
	2-Star Alignment	Yes	Level of Telescope	telescope with the
SITE
				SITE information
				available.
2-Star:				Best used when the
Unknown	2-Star Alignment	No	N/A	SITE information is
SITE				not available.

*Atmospheric Refraction Correction: Light from a astronomical object is "bent", or refracted, as it passes through the atmosphere. This bending is more pronounced near the horizon because there is more atmosphere for the light to pass through, and it shifts the apparent position of the star. The LX200 calculates this bending and compensates for it when slewing to objects near the horizon.

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