I first review the status of Digital Sky Surveys. The focus will be onextragalactic surveys with an area of more than 100 sq.deg. The Sloan DigitalSky Survey is the archetype of such imaging surveys and it is its great successthat has prompted great activity in this field. The latest surveys explorewider, fainter and higher resolution and also a longer wavelength range thanSDSS. Many of these surveys overlap particularly in the S Hemisphere where wenow have Pan-STARRS, DES and the ESO VST surveys, and our aim here is tocompare their properties. Since there is no dedicated article on the VST ATLASin this symposium, we shall especially review the properties of this particularsurvey. This easily fits onto our other main focus which is to compareoverlapping Southern Surveys and see how they best fit with the available NIRimaging data. We conclude that the Southern Hemisphere will soon overtake theNorth in terms of multiwavelength imaging. However we note that the South hasmore limited opportunities for spectroscopic follow-up and this weakness willpersist during the LSST era. Some new perspectives are offered on this andother aspects of survey astronomy.
展开▼
