Dawes limit for HST?

http://imgsrc.hubblesite.org/hu/db/2...s/full_jpg.jpg

The reddish binary stars in the upper left seem to suggest a dawes limit for
HST. Ya think?

On Tue, 10 Aug 2004 01:20:25 GMT, "MikeThomas" wrote:

http://imgsrc.hubblesite.org/hu/db/2...s/full_jpg.jpg

The reddish binary stars in the upper left seem to suggest a dawes limit for
HST. Ya think?

The WFP camera on the HST undersamples the PSF. Sometimes, a processing
technique called drizzling is used to boost the resolution. Without knowing more
about this image, however, it isn't possible to determine if you are up against
the resolution limits of the scope or the camera. Do you have the link to this
image that contains the image details?

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

"Chris L Peterson" wrote in message
...
On Tue, 10 Aug 2004 01:20:25 GMT, "MikeThomas"
wrote:

http://imgsrc.hubblesite.org/hu/db/2...s/full_jpg.jpg

The reddish binary stars in the upper left seem to suggest a dawes limit
for
HST. Ya think?

The WFP camera on the HST undersamples the PSF. Sometimes, a processing
technique called drizzling is used to boost the resolution. Without
knowing more
about this image, however, it isn't possible to determine if you are up
against
the resolution limits of the scope or the camera. Do you have the link to
this
image that contains the image details?



What is PSF? Here is a link that may help.

http://hubblesite.org/newscenter/new...eases/2004/25/

On Tue, 10 Aug 2004 07:42:29 GMT, "MikeThomas" wrote:

What is PSF?

That's the point spread function. It is essentially the profile you see at the
image plane of a point source. For a telescope on ground, its size is usually
determined by the seeing conditions. In space, it should be determined by the
optics alone. In the case of the WFPC2 instrument, the pixels are larger than
the spot size the telescope is capable of producing. That is called
undersampling, and it means that the resolution of the images are limited by the
camera, not the optics.


Here is a link that may help.

http://hubblesite.org/newscenter/new...eases/2004/25/

They don't really detail the processing. If they didn't use the drizzle
technique, than what we are seeing is less resolution than the telescope is
actually capable of.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com