After moving away from Fallbrook, CA to Oceanside in 2012 for non-astronomy reasons, I realized that I
needed to start driving out to dark sites again to pursue my night sky photography as the location of lights
and light pollution in and around my apartment complex was not really conducive to successful imaging. Due
to the complexity of equipment I had amassed over the years, this turned out to be quite a chore and some
friends and I started researching where a good location to situate an observatory would be so that we could
all do some serious astrophotography without having to haul a ton of gear around all the time. I had the
telescope but little additional cash available, but a couple of my friends wanted access to a good imaging
setup like mine without needing to acquire everything themselves so it made sense to pool our resources.
The spot that we chose as the best fit for the observatory was the Riverside Astronomical Society's GMARS
dark sky site in the town of Landers, CA - www.rivastro.org/. Landers is around 120-130 miles from both
north San Diego County and coastal Orange County where my friends Cris, Sean, and Matt hail from, so the
site is usually not more than around 2 1/2 to 3 hours away, depending on traffic. The site is also around 20
miles north of Joshua Tree National Park, giving us all easy access to photograph stunning landscapes as
well within an easy drive. The site is fairly dark as well, as can be seen from the Light Pollution map of the
area. Typical Sky Quality Meter readings are around 21.4 mag/sq arcsec (around mag 6.4 ZLM) and except
for winter storms and the monsoon season that crops up in the summer the nights are mostly clear. Like
many desert sites in southern California, seeing is often a bit unstable at an average of 3-4 arcsec, but as the
equipment we were installing was set up to shoot widefield images with a scale of around 1.9 arcsec/pixel at
only 800mm focal length that was a minor issue at this time.
The final motivation was that RAS had a pre-built observatory become available within a couple months of us
joining the club, so we jumped at the opportunity and bought Observatory #3. With tongue in cheek humor
and some input from my girlfriend Barbara, we decided to name the observatory "The Nerdery," but as we
relish the technical challenges of getting a project like this working given our long friendships and interest in
science and astronomy, we are proud of this pursuit toward more advanced photography of the night sky.
Observatories at GMARS follow a common floor plan. There are 15 roll-off roof buildings 10' x 12' in size,
and the roofs slide off to the north on metal rails supported on a wooden frame to open up a view of the sky.
Walls are about 6 1/2 feet high and do a good job of blocking wind from the outside and the floating floor and
isolated concrete sub-pier prevent someone walking around inside the building from transmitting vibrations to
the telescope. Many of the roofs have been motorized by their owners and some are in the process of being
converted to full remote operation.
Given the distance all of us have to travel, automation was the overarching goal for the observatory project,
but in the meantime there were several challenges that needed to be overcome first. We had to pull out the
wall panelling to add insulation to the walls and inside the roof, and two of the flimsy 2x4 roof beams were
replaced with pressure treated 4x4 beams. Puzzle piece floor mats were laid down to cushion the floor and a
desk was thrown together to give the observatory control laptop something to sit on. A large Craftsman tool
chest holds necessary maintenance tools as well as other odds and ends, and a small refrigerator and
microwave make it even more of a man cave in the desert than it was before.
A 10" steel pier was acquired from Software Bisque to attach to the concrete sub-pier and then ADM and
Losmandy adapters were used to anchor the ASA DDM60 mount in as close to a true northerly direction as
possible. Once the rest of the scope was assembled, a cable run was bound together with short strips of spiral
wind conduit to get all of the power and data over to the wall underneath the computer desk. The scope and
accessories were all carefully balanced before everything was carefully polar aligned and an all-sky pointing
and tracking model was shot using the Apogee U16000 CCD camera and ASA's plate solving software
Sequence. The mount is aligned to the pole by less than 1 arcminute - accurate enough for very long
exposures with or without autoguiding - and the pointing precision is ~ 20-30 arcseconds all over the sky.
A monochrome ASI120MM camera from ZWO serves as the observatory's interior all-sky camera as well as
transmitting images that confirm whether the scope has returned to its home position and whether the roof is
open or fully closed.
There are still a lot of thing that need to be done on the observatory, so expect that there will be edits to this
page as tasks are completed. Here are the major things on our list as of July 1, 2014:
* Motorize the roof and control from MaxIm DL or other control software
* Install backup power supply and air conditioning system for hot summer months
* Add weather station and integrate emergency closure procedure for wind or rain
* Set up dedicated RF internet connection for remote operation
* Install observatory control software that can allow sequences through the meridian with all calibration
frames and roof closure at end of night automated.
Even when the observatory is fully automated, we will still meet up out at GMARS from time to time. It's a
very cool place with friendly people and the proximity to Joshua Tree National Park makes it a convenient
place to crash when doing late night photography in the park. This project has been a blast so far and I can't
wait to see what more is in store for the Nerdery in the future!
|The Nerdery Observatory - RAS GMARS site, Landers, CA