Project PANOPTES


Polar Alignment Success!
2015-08-30


 

On Saturday, Aug 29, Nem, Josh, and myself went up to do some work on PAN001 up at the Mauna Loa Observatory. We had two goals set for the day:

  1. Adjust the adapter plate for PAN001 so we could inset a locating pin used for polar alignment.
  2. Polar align the unit.

Hurricane Ignacio, which just that morning had turned into a Category 4 just a few hundred miles to the east, was on the way, so we were eager to get the work done that night as we didn’t know if we would be able to come up the entire next week. The weather on Saturday, however, was perfect:

Left: In between the hardware fixes and the polar alignment, we pause to admire the beautiful view from MLO. Haleakala is in the distance. Right: The setting sun at the MLO facility. Left: In between the hardware fixes and the polar alignment, we pause to admire the beautiful view from MLO. Haleakala is in the distance. Right: The setting sun at the MLO facility.
Left: In between the hardware fixes and the polar alignment, we pause to admire the beautiful view from MLO. Haleakala is in the distance. Right: The setting sun at the MLO facility.

Hardware Fix

When we first built the pier up on MLO we were using an iOptron iEQ45 Pro. This is a good, large mount, but was always supposed to be a temporary mount while we waited for the iEQ30 Pro’s to be available. However, the base for the iEQ45P and the iEQ30P is different, so when we finally did receive the iEQ30P’s, we had to create an adapter plate that could sit on top of our already installed pier. All of this work had been done previously by Nem and the adapter plate worked like a charm, however what we had discovered last time we were up at MLO is that it was nearly impossible to do a correct polar alignment because the adapter plate (actually, the entire pier design at that time) didn’t include a locater pin. Nem had easily solved the problem for the design of the pier and all that was needed for PAN001 was to drill out a small hole on the adapter plate to insert the dowel. This went more or less without a hitch, with Nem able to slide the adapter plate out from underneath the mount so that we didn’t even have to take down the whole unit. Work done early, and the weather (and lack of wind) working in our favor, we had about an hour left of light before we could do the polar alignment and spent the time enjoying the beauty of Mauna Loa.

Polar Alignment

Once the sun went down and the stars came out we set about doing the polar alignment. The trick here is simple: start with the mount completely horizontal and facing what you think to the center of the celestial pole, then expose your camera while you rotate the mount around the RA-axis. You can see the images we took below. The whole process took about 45 minutes and we were within 0.5 °, good enought for us to begin taking data and testing the unit.

A sequence of images taken during polar alignment. The idea is that the center of the arc should be exactly north. Any mis-alignment will cause the arc to be distorted in shape or offset from the north. We performed this on a full moon night so the images get progressively lighter as it gets later.
A sequence of images taken during polar alignment. The idea is that the center of the arc should be exactly north. Any mis-alignment will cause the arc to be distorted in shape or offset from the north. We performed this on a full moon night so the images get progressively lighter as it gets later.

The Timelapse

Nem captured the night on his GoPro.