Astronomical imaging using ground-layer adaptive optics

Christoph Baranec, Michael Lloyd-Hart, N. Mark Milton, Thomas Stalcup, Miguel Snyder, Vidhya Vaitheeswaran, Don McCarthy, Roger Angel

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

9 Scopus citations


Over the past several years, experiments in adaptive optics involving multiple natural and Rayleigh laser guide stars have been carried out by our group at the 1.5 m Kuiper telescope and the 6.5 m MMT telescope. From open-loop data we have calculated the performance gains anticipated from ground-layer adaptive optics (GLAO) and laser tomography adaptive optics corrections. In July 2007, the GLAO control loop was closed around the focus signal from all five laser guide stars at the MMT, leading to a reduction in the measured focus mode on the laser wavefront sensor by 60%. For the first time, we expect to close the full high order GLAO control loop around the five laser beacons and a tilt star at the MMT in October 2007, where we predict image quality of < 0.2 arc seconds FWHM in K band (λ = 2.2 μm) over a 2 arc minute field. We intend to explore the image quality, stability and sensitivity of GLAO correction as a function of waveband with the science instrument PISCES. PISCES is a 1-2.5 μm imager with a field of view of 110 arc seconds, at a scale of 0.11 arc seconds per pixel. This is well matched to the expected FWHM performance of the GLAO corrected field and will be able to examine PSF non-uniformity and temporal stability across a wide field.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - 2007
EventAstronomical Adaptive Optics Systems and Applications III - San Diego, CA, United States
Duration: Aug 29 2007Aug 30 2007


OtherAstronomical Adaptive Optics Systems and Applications III
CountryUnited States
CitySan Diego, CA



  • Adaptive optics
  • Ground-layer adaptive optics
  • Infrared instrumentation
  • Laser guide stars
  • Wavefront sensors

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Baranec, C., Lloyd-Hart, M., Milton, N. M., Stalcup, T., Snyder, M., Vaitheeswaran, V., ... Angel, R. (2007). Astronomical imaging using ground-layer adaptive optics. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 6691). [66910N]