`SITE: GILLAM, MB`

DOME INSTALLATION - TASK DESCRIPTION

NEW ASI (POLARIS) PREFERRED DOME LOCATION (GILLAM TRAILER): Calgary requests that the Polaris ASI dome (1-m diameter) be situated towards the middle of the EAST wall (presently occupied only by a shelf high off the floor). This location will provide maximum unobstructed view of the aurora. The dome should be located as close to the wall as practically possible. Plywood reinforcement should be provided to the adjacent wall (wall-to-ceiling) to permit Calgary to mount their hardware. Some means of attaching a Calgary-suppled dark-curtain to the ceiling surrounding the dome mount area, and a GPS antenna (as described in an earlier communication) under the dome, should be provided. The actual slope of the roof is at the time of writing not known, but a box insert for the dome may be required so as to bring the dome high enough up to provide an unobstructed horizon-to-horizon view for a lens mounted at the center of curvature of the dome. Mounting the dome at the roof slant angle would in principle be acceptable, as long as the top of the lens can remain within a radius of +.1 m of the center of curvature of the dome, while still retaining the clear 360 deg view of the horizon. The dome should be equipped with a metallic outside collar to prevent snow buildup on horizontal flange. Such a collar would also be conducive to further keeping dome-roof interfaces dry and watertight. Finally, Calgary requests that a simple workbench be constructed and located on the east wall, between dome and door, ~26" above the floor. This bench will be populated by a standard 17" computer monitor (50" X 40" footprint), keyboard, UPS (18"x7" footprint), and a minitower PC (18"x8" footprint), total weight approximately 50 pounds.

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DOME INSTALLATION (AUGUST 1999)

Optical-grade hemispheric domes were manufactured by Talbot Designs Ltd., U.K. Telephone 0044 (0)181 346 8515.
Sales rep was Mr. Richard Woolff (sales@talbotdesigns.co.uk).
Plexiglass transmission curve is shown here.

Outside View

The CSA contractor (SED) provided a raised horizontal extension of the roof to provide an unobstructed, horizon to horizon view. This extension placed the base of the dome above the roof peak. The dome was placed onto a wooden structure that fit inside the dome lip. This inside seam was sealed with Latex Caulking. Because of the dome lip, there should never be water leakage here. The wooden structure is covered in tin. The seams, which are overlapped, are sealed with black tar, commonly referred to as ``Bear Shit.'' This compound is found on all roofs, residential and commercial. It has a good lifeline. It should last 3 or 4 years, but we plan to check it on a yearly basis, and reapply as necessary. If it were to leak, the water would enter the roof of the building and lay in the ceiling. It would not appear in the inside dome area.

Inside View

The ceiling to floor distance is 8'. As seen, the hole opening is flush with the outside wall, so the horizontal distance from the wall to the vertical extension of the Center of Dome is 350 mm. The dome is centered over the hole opening. The visible hole from inside the building is 700 mm square. From outside, looking into the dome, the hole is 700 mm in diameter (round). That provides 4 corner pieces of 3/4 " plywood to mount fans, GPS antenna, etc. On the East wall the plywood is 1 3/4" thick.

Dome Physical Characteristics

[Finnish Meterological Institute's dome installation, using domes identical to ours. Wooden ring.]

Polaris Instrument Bench.

IMAGER INSTALLATION (MARCH 2000, by U of C)

Wall-mods by Kaare

Trapped personnel

Trond tweaking pot.

Polaris mounted under the dome. GPS antenna clamped to dome ledge.
Note the two supporting brackets and the crossbar onto which the imager is mounted (this is the U of Calgary ``H-Mount'' imager mounting method). The tail of the imager is supported by the wall using two metal rods (adjustable length), not seen here. The imager weighs approximately 20 kg, it's length is 1000 mm and its outside envelope is dictated by the 260 mm diameter filter wheel.