Dome Flats

Observations of a uniformly illuminated screen within the telescope dome may be substituted for the twilight sky. As with the sky, though, the a sequence of exposures would be taken as the intensity of the screen illumination is gradually increased or decreased. The flat-field image would be constructed as in 3.3.

Advantages:

Acquisition of the flat-field data is greatly simplified. The color temperature of the illumination source can be tailored to match typical astronomical sources. Again, this procedure uses the existing pipeline design with single, fixed flat, so there would be minimal impact in design and processing speed.

Disadvantages:

Historically, dome flats have been found to be ineffectual for near infrared imaging. However, the variable intensity measurements have not been tested to our knowledge. Requires upkeep of flat screen.