The Survey Areas Definition Tool is part of the VISTA Data Flow System
Project (a separate project to the VISTA Project) and was delivered to ESO for use with VISTA and (later) VST. The development team was led by J.P. Emerson of Queen Mary, University of London with Java software written by staff (then) working at the UK Astronomy Technolgy Centre, Edinburgh (Martin Folger, Nuria Lorente, Albert Heyrovsky).
The SADT and can be found via the ESO SADT page and includes inter alia
- Software: The SADT software at ESO in the 2009-Sep-24 ESO release (v3.040 was last modified 2009-Jul-07)
- The version of SADT used in P85 was v3.09 on 2009-12-18
- The version of SADT used in P86 was v4.xx on 2010-
- The version of SADT used for P87 was v5.02
- Cookbook: ESO's SADT Cookbook via the ESO SADT page
- Manual: The SADT_Manual_v2.0_20090911 referred to in the Cookbook was written by J Emerson and used to derive the Cookbook and duplicates some information also found in the VISTA User Manual.
- v5.05 is the VST-only version of SADT for VST dry-runs. This should NOT be used for VISTA!!!
- Three OMEGACAM_paf files for VST must be put in the OMEGACAM IP
Installation & Running
Install P2PP before you run SADT - See the Cookbook
Y overlap values
The Y overlap value set in SADT controls how the Y edges of adjacent tiles overlap.
Some examples are given below. The default value (+60 arcsec) is recommended because this represents efficient use of the two +Y & -Y singly covered strips in each tile by matchign them with the corrsponding once covered strips in the adjacent tiles, with the 60 arcsec allowing matching of sources in the (resulting) twice covered edfe strips between tile to ensure the global photometry.
Y overlap 0/60 efficiently uses the one time covered regions to make a 2x covered region
Y overlap +330/+390 does not use the one time covered regions to make 2x covered regions but rather makes some 3x covered regions
|Y overlap (arcsec) set in SADT
||Once covered regions just touch
||Strips of 1x exposure time between each pair of 2x exposure timetiles. This would (just) give full sky coverage but it would be of very non unifrom depth with the lowest exposure time varying by a factor of two (1x or 2x)
||Once covered regions just fully overlap
||This would (just) give full sky coverage (2x) with a minimum exposure time which does not vary over the sky. This is achieved by turning the 2 overlapping x1times exposed strips into a single 2times exposed strip
||Twice covered regions (made of 2 x 1coverage) overlap by 60 arrcsec
||This would give full sky coverage (2x) with a minimum exposure time which does not vary over the sky, and a 60 arcsec tile to overlap for matchign photometry from tile to tile.
||Twice covered regions (made of 1 x 2coverage just touch
||Twice covered regions just touch and the two 1x covered strips are not used to genrate the equivalent 1 x 2times covered stip.
||Twice covered regions (made of 1 x 2coverage) overlap by 60 arrcsec
||Oriignl twice covered regions overlap by 60 arrcsec