Image Quality Statistics Gemini North and South

Each night (weather permitting), a few images of a relatively dense stellar field are collected using the Acquisition Camera and R-band filter. Typically this occurs at the start of the night when the primary mirror figure (active optics) is first tuned as well as later during the night.

The images are analyzed automatically and FWHM (image quality) and ellipticity values are derived. The image quality is corrected to zenith pointing as sec(zenith distance)^0.6. The ellipticity measures the accuracy of primary mirror (M1) low-order figure and of M1/M2 alignment. Results are plotted below.

The instructions to take these images and a list of target can be found here.

Here (GN and GS) are the raw data, in the format
image_name date time #_of_stars_used fwhm fwhm_err ellipticity ellipticity_err daophot_roundness roundness_err .
The database and the following links are updated every days at 6:00AM.

Below you will find for Gemini North and South:

• Histogram of IQ
• Histogram of image ellipticity
• IQ vs time from the beginning of the seeing data collection

Gemini North	Gemini South
Histograms of raw image quality

Gemini North	Gemini South
Histograms of image ellipticity

Gemini North	Gemini South
Night-averaged seeing and ellipticity versus time