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View Full Version here: : Southern Sky Survey (using Skymapper)


NereidT
23-03-2012, 06:33 AM
The Southern Sky Survey (http://msowww.anu.edu.au/skymapper/survey.php) is a multi-year ANU project, using Skymapper (http://msowww.anu.edu.au/skymapper/index.php).

Does any IIS member have any direct experience with it?

Does anyone know if its output will be at all like that from SDSS (http://www.sdss.org/), e.g. like DR8 (http://www.sdss3.org/dr8/) (minus the spectroscopy of course)?

madbadgalaxyman
26-04-2012, 09:43 PM
I believe, from my previous reading, that it is the intention of the skymapper team to make images, in the u & g & r & i & z bands, of the entire southern sky (= 20,000 square degrees). They intend to put this entire imaging dataset into the public domain by means of virtual observatory tools (similar to the SDSS interfaces and/or the National Virtual Observatory of the United States), but I am uncertain as to what precise interface they will use to display the sky images and the measurements.
They have announced their intention to provide images of all of the objects detected, to the general public, but whether the interface will be like SDSS DR8, I do not know.

(g+r+i+z are similar to the imaging bands used in the Sloan Digital Sky Survey, and I believe that the u band is Stromgren-like )

The design goals of the Skymapper imaging data are actually exceedingly modest (say 1-1.5 arcsec resolution), and I can only assume that this is because Skymapper is at a site with mediocre seeing (Siding Spring) when compared to the very best sites in the world. Also, the imagery will be remarkably shallow, when you consider the depth that modern telescopes are capable of.
Note: The provision of an imaging survey of the entire southern sky is only a small part of the scientific rationale for Skymapper, so it is not optimized for image quality.
But when you consider the rather limited angular resolution of the Skymapper data, you realize that skymapper should have been put at a better site..... overseas!!

A similar sky survey, of the entire southern sky, is to be undertaken by the VISTA telescope in Chile, but the VISTA images will be much deeper and of much higher angular resolution (0.5 arcsec) than the Skymapper images.

Both Skymapper and VISTA seemed to have gone awfully quiet, last year, which might be a sign of problems and delays. (SDSS took many more years to get going than was originally anticipated!!). There has been some talk of a five year timeline for the Southern Sky Survey, so it could be a while before the data becomes available......