[AZ-Observing] Re: FWHM measurements for Phoenix skies, anyone?
- From: Tom Polakis <tpolakis@xxxxxxx>
- To: az-observing@xxxxxxxxxxxxx
- Date: Mon, 21 May 2007 2:04:33 -0400
Matt,
Back when I was imaging with my ST-7 and 13-inch in Tempe, I routinely had 2 to
3 arcsecond FWHM seeing, as reported by MaximDL. It is always good to keep the
scope at least 45 degrees above the horizon, so imaging objects within a couple
hours of the meridian is crucial. There have been many words written about
image scale. For what it's worth, my 13-inch delivered 1.2" per pixel at the
chip.
I never set the CCD imager up at a remote site, but my experience with visual
planetary observing has been that our desert sites are no better, and perhaps
worse, with regard to seeing than my back yard.
If you are interested in Webcam imaging, however, you want that image scale to
be only several tenths of an arcsecond per pixel.
As for the definition of FWHM (full width at half maxium), there's an entry in
Wikipedia.
http://en.wikipedia.org/wiki/Full_width_at_half_maximum
Tom
--
See message header for info on list archives or unsubscribing, and please
send personal replies to the author, not the list.
Other related posts:
