Status of the MMT observatory multiple laser beacon projector

Thomas E. Stalcup, Roger Angel, Michael Lloyd-Hart, Matthew J. Rademacher

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

1 Scopus citations


The laser guidestar system at the MMT Observatory has produced its first closed loop results and should be producing ground-layer corrected closed loop images within a few months. The LGS system at the MMT is one of few in the world that uses atmospheric Rayleigh scattering from reliable, low-cost lasers, and is unique in its use of a dynamic refocus technique to increase the telescope depth of field for increased return flux. The resulting 10 km depth of field introduces additional constraints on the minimum spot size for the beam projector design. The short exposure spot size as measured at the telescope cassegrain focus is 0.65 arcseconds in 0.59 arcsecond seeing in the visible. Additionally, a method to correct for image motion due to telescope vibrations using accelerometer data has been successfully implemented.

Original languageEnglish (US)
Title of host publicationAstronomical Adaptive Optics Systems and Applications III
StatePublished - 2007
EventAstronomical Adaptive Optics Systems and Applications III - San Diego, CA, United States
Duration: Aug 29 2007Aug 30 2007

Publication series

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


OtherAstronomical Adaptive Optics Systems and Applications III
Country/TerritoryUnited States
CitySan Diego, CA


  • Accelerometer vibration correction
  • Dynamic refocus
  • LGS
  • MMT
  • Multiple laser guide stars
  • Rayleigh beacon

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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