Height of Observatory

[iandh]

Hi,

Can anyone help me locate an article that I once read about the ideal height above ground level for the base of an observatory slot.

 

I am helping with the design of a new observatory and I remember reading an article several years ago that came up with a suggested optimum height for the base of the open slot to reduce turbulent airflow and thermals from the ground.

 

Unfortunately many web searches later, I have still not relocated it................

 

Many Thanks

[RayD]

Guess it would depend how high your pier is, but below are the dimensions for a Sirius one, which is one of the prefabricated models, so I assume using relatively standard dimensions with a wall height (bottom of dome) of 1.5m?

Total Height: 2.83m / 9'3"
Wall Height: 1.5m / 5'0"
Diameter: 2.3m / 7'6"
Door Size: 1.15m H x 1.0m W / 3'6" x 2'6"
Aperture Width: 0.6m / 2'0"
Open past zenith: 250mm / 0'10"

[Peter Drew]

Based on having built around 20 observatories I would suggest that the base of the opening should allow a full apertue to be available with the telescope horizontal. Regarding dome slot dimensions, it's nice to have them as wide as is structually possible and extending past the zenith enough for an unobstructed aperture.  

[iandh]

Hi Petr and RayD,

Many thanks for your help. 

Ray D - I think that like my Pulsar observatory, they design the wall height to bring the top of the dome below the height at which Planning Permission is required, 3m I think. We are going to have to go for full planning permission on this project as the dome will be 6m diameter, therefore >3m total height.

Peter - Yes thanks we had spotted that one but we will be constructing a solid concrete pier as the scope weighs close on 3 tonnes. Therefore we can easily extend it to give the full aperture requirement that you mention, to match the height of the bottom of the slot. We intend to put a mezzanine floor in for the observation deck.

Regards

Ian

[malc-c]

Check with your local planning office, there are constraints on height when the structure is within a certain distance to a boundary fence.  When I built mine it was max 2.5m to the ridge if the structure us within 2m of a boundary.  My ground slopes, so they take the height over both ends and average it out, so at 2.3m I came within the constraints.