1 Overview 2 Details of the Model Construction - Canada France ...

adhesive had been applied) to the dome. These steps required great care to avoid having the
cyanoacrylate spread on the dome or have its vapors fog up the acrylic. Thoroughly wiping all surfaces
with denatured alcohol prior to work helped minimize fogging.
The observatory model was mounted on a plywood cutout model of the terrain at CFHT. The terrain
was a scale replica taken from a topographic map, and was made by Eli Hart as part of his internship at
CFHT in the summer of 2010. The terrain was oriented so that the east side was directly facing the
flow direction in the water tunnel, which corresponds roughly to the median prevailing wind direction
at the observatory. The terrain model consisted of 8 layers of 3/8” marine grade mahogany plywood
mounted on a 91.4 cm x 74.9 cm x 3/8” (36” x 29.5” x 9.5 mm) rectangular base sheet. The base sheet
had a rounded leading and trailing edge to reduce surface effects in the water tunnel. The scaled
height represented by the terrain (not including the base sheet) is 12 m; this corresponds to 1.5 m of
elevation per step in the terrain. All wooden parts were treated with at least one primer paint coat
followed by 2 coats of exterior grade acrylic based white paint. Despite this, some minor delamination
of the plywood was noticed on the fourth day of testing.
Figure 5: View of the south side the small vent dome model
The azimuth angles written on the dome base ring correspond to the direction of the slit (shutter
aperture) with 0 degrees at north, 90 degrees to the east, 180 degrees to the south and 270 degrees to
the west with a fixed fiducial set directly south.
3 Testing in Waimea
A plywood and glass tank with cross sectional dimensions similar to that of the UWAL water tunnel
was constructed by Roger Wood for use at HQ in Waimea. This was used to test visibility of the model