Techniques of Observational Astronomy
AST3722C

CCD Problems

Examples

Many Examples of Problems http://www.ciw.edu/vonbraun/obs_mishaps/mishaps.html

Other examples of good and bad CCD frames http://www.siowl.com/index.html?CCDproblems/CCDProblems.html

Cosmic Ray Events

From Dan McKenna (mckenna@as.arizona.edu)

Cosmic Ray interactions as you know are almost always seen on CCD images.
In addition you can get tracks from local sources like the window. We test
CCD cameras with xray sources like Fe 55 also.
The first TI CCD, years ago, had a radioactive header and produced a large
number of back ground events.

Both primary and secondary particles produce tracks. The rate is a strong function
of altitude. During a solar flare if you look at the soho site data you can see an
increase in the background.

The nominal fluence level at sea level is about .025 cm^-2 sec ^-1 which translates
to about 90 events per square cm per hour.

The Rays are composed of 74% muons, 25% electrons, and 1% protons
M. Roos, et. al. "review of particle properties", Phys. Letters 111b, 83 (1982)

Muons have a mass of 207 electrons and are generated as a result of spallation when
the CR interacts with high altitude atoms in our planets atmosphere.

Condensation and Frost

Condensation http://spiff.rit.edu/richmond/ritobs/wierdflat/nastyedges/wierdflat.html

Frost http://www.starkenburg-sternwarte.de/sternwarte/geraete/ap7/fog.htm

Ice Crystals http://a188-l009.rit.edu/tass/markiv/leaf.gif

This page is maintained by John P. Oliver; write me at oliver@astro.ufl.edu
This material is being made available to you subject to a variety of caveats.

This page was last edited April 29, 2004 6:02 AM