Pointing Models

Pointing Offsets

• The Linear ADC will produce a fairly large offset (0.7 arcmin) when fully extended. The Keck pointing model will need to take this into account. However, offset is always in elevation.

Tracking

• Bulk effects such as rotation of the field and scale changes between field center and guider should be removed for best performance.
• These effects can be ameliorated by short exposures (direct imaging) or semi-frequent mask realignment (spectroscopy).
• The magnitude of these effects needs to be derived.