Overview of site monitoring at SAAO

T. Pickering, S. M. Crawford, L. Catala, D. Buckley, A. Ziad, R. Wilson

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


We present a comprehensive review of the first two years of a site monitoring campaign at the South African Astronomical Observatory (SAAO) located outside Sutherland, South Africa. This campaign is in support of the Southern African Large Telescope (SALT), a 11-metre, fixed-elevation, optical telescope located at SAAO. The heart of this observing campaign involves continuous monitoring of the site by a MASS-DIMM instrument. The MASS-DIMM has been in routine use since March 2010 and its operation is now fully automated. At the beginning of this campaign, simultaneous observations were also made by a SLODAR instrument, which allows high resolution observations of the lower atmosphere. In August 2011 a two week campaign was carried out with a two-channel Generalized Seeing Monitor (GSM) telescope along with a lunar limb profiler (Profileur Bord Lunaire; PBL). Combined with the MASS-DIMM data these observations provide multiple independent measurements of atmospheric turbulence as a function of height. They also help improve the calibration of our site for more direct comparison to other major astronomical observatories. Our results so far indicate that the atmospheric conditions at the SAAO Sutherland site have deteriorated compared to past measurements. The ground layer accounts for the majority of the integrated seeing, while the free atmosphere seeing is comparable with other major sites.

Original languageEnglish (US)
Title of host publicationGround-Based and Airborne Telescopes IV
StatePublished - 2012
Externally publishedYes
EventGround-Based and Airborne Telescopes IV - Amsterdam, Netherlands
Duration: Jul 1 2012Jul 6 2012

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherGround-Based and Airborne Telescopes IV


  • Site testing-seeing
  • Southern African large telescope

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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