Mees Dome Seeing Improvement



The intent is to minimize the contribution of the dome seeing to the degradation of image quality. The general plan is to eliminate heat sources in the dome and increase the flow of air to equalize the temperature with the outside air.

Heat Source Reduction

The first step is to make measurements of the local heat distribution inside, from natural and manmade sources.

  • Temperature survey, Nov 6 1997
  • Verify probe operation
  • Temperature survey and findings, Feb 25 1998
  • Temperatures of buildings and surroundings, Aug 18 1998

    Airflow Increase

    The dome slot with windscreens in place gives a hole about 2 meters square. The outside door is about half that size and is the only other place for air to flow. Cutting more ports in the cement block of the dome wall is not a good idea; it weakens the structure and is blocked by the coude room along the south side. The steel skin of the dome can be cut and reinforced. A series of windows in the dome gores would increase the area for airflow by a factor of 5 to 10. Issues are: structural design to insure the strength of the dome is retained; mechanisms for opening and closing the ports; seal design to insure the ports will not leak in high winds, rain, snow, or ice storms.

    The 4 meter telescope dome at Kitt Peak was recently modified in this way. From the Dec 1997 newsletter.

    The UKIRT on Mauna Kea was also upgraded with dome vents.
    Photo
    Upgrades

    Big Bear installed more conventional ductwork and fans to force better ventilation. They also insulated the interior of the dome.

    Mees dome structure and images

    Action Plan

    Tasklist, 27 Jul 98.

  • 1d) Power survey, 15 Oct 98
  • 1e) Coude room temperature, 15 Oct 98

    • Last modified: Mon Oct 19 09:29:54 HST 1998