The pier as it is called is the center piece and one could argue most important part of an observatory. The pier is what the telescope rests on and a stable platform is critical when you want to take astro photos. I put a lot of time into researching and thinking about the type of pier I wanted to use and I ended up going with pier tech. This pier is a square metal column that is mounted to a plate set in concrete on or above the ground. Our concrete pillar ended up using 3000 pounds of concrete and was a pear shaped block at its widest point 3×3 and narrowest 2×2. The pier is two feet off ground level and is buried three feet under ground.
Another element of pier placement and development planning is the true north issue. Telescopes need to be mounted in a specific way so that they are pointed exactly true north. True north and magnetic north are different, so using a compass is unreliable. I wanted the structure of the observatory itself to be set to true north, meaning the east and west walls point exactly north and south. The building itself is a compass pointing at true north. The frame for the pier was set in the center of the structure and its walls are parallel with the buildings walls. To determine true north markings I used a variety of methods including: using a compass and offsetting for magnetic north (not recommended), using a sun dial at solar noon, using a telescope / the stars with drift alignment (and then marking the ground based on wedge location) and using a GPS. When all was said and done we got it right. For those of you who want to know the best way to find true north, I would recommend using a good hikers GPS (or iPhone compass) to figure it out.
Here are some pics of the pier construction. These are from a few weeks ago, the observatory is nearly completed, I will post more pics of the construction soon.