HOW TO BUILD A REMOTE OBSERVATORY – THE STORY OF DEEP SKY WEST
Introduction. This article is as much about Deep Sky West (DSW, www.deepskywest.com) as it is instructional. You can use the concepts presented in the ‘Story of Deep Sky West’ to create your own remote observatory—even in your own back yard. In fact, “going remote” at home is the best way to ensure success when you’re really remote.
DSW is a remote astrophotography observatory situated on Glorieta Mesa in Rowe, New Mexico. This high altitude site (elevation 7,400 feet) offers pristine dark skies, transparency, excellent seeing, and weather conditions coveted by all imagers. We make remote imaging and hosting affordable for the “average” backyard astrophotographer by offering exceptional value and promoting teamwork.
DSW was born on a rooftop in the middle of a 35-acre plot of land on New Year’s Eve 2014. Say what? Yes, Bruce Wright and I hatched the plan for DSW while staring at the inky black night sky from the roof of his underground house on the eve of 2015. Bruce’s life-long dream of building an energy-efficient, off-the-grid home sat beneath us while the most incredibly transparent sky encircled us from horizon to horizon. While I appreciated Bruce’s accomplishment, the astrophotographer in me realized that the
highest and best use of this location was not underground, but overhead. We decided to build DSW that night, but we wanted DSW to be different. By June of 2015, DSW Alpha 1.0 saw first light.
Our tag line says it all: “Remote Imaging for the Rest of Us”. Our primary goal is to make remote, dark site imaging affordable and attainable for the beginning astrophotographer to the most ardent amateurs and even professionals. DSW promotes teamwork—it’s one of our guiding principles and puts dark site imaging within reach of the backyard imager. There’s no need to re-invent the wheel since we’ve already procured a site, implemented the infrastructure, built the observatory, and hired on-site support. Affordable remote imaging, every clear night, is within your grasp—no building, no driving, no sleepless nights, no hourly points systems, no creepy crawlers and no wasted trips.
DSW’s target audience is the astrophotographer who has a love for the hobby, sometimes has great equipment, but is plagued by poor skies. The lack of consistent clear skies results in equipment going idle for long periods. When the weather does cooperate many imagers have to travel to remote locations, set up equipment from scratch, polar align, image (if the weather holds up), and tear it all down again at the end of the session. Imagers fortunate enough to have a home observatory don’t have the hassles of setting up
for each session, but many locations lack quality skies.
Whether you’re a seasoned imager or just starting out in the hobby you’ve realized a few fundamental facts about our shared pursuit: 1) it’s really hard and 2) it can be very expensive. How could we solve for both of these issues? We created two separate business models within the same observatory. One is traditional wherein an imager leases a pier and operates their own system remotely. This is remote imaging in the “classic” sense: you operate your equipment as you see fit, perhaps you work with a small group of friends and you split expenses—this is up to the team.
The other model is a virtual team shared system concept wherein imagers from around the world choose the targets for our DSW-operated systems, we manage data acquisition, and the members receive all the data collected on the system(s) of their choice. This model has proven quite popular. Interestingly enough this also generates some controversy! There’s a school of thought that says in order to be considered a “real” astrophotographer one must perform their own data acquisition and image processing. It’s the collection part that seems to be at the center of the issue. Clearly our shared-system model removes the data acquisition part of the equation, but the processing is left up to the member. Our position is clear: if you don’t have the equipment, skills or skies you should not be denied the opportunity to participate in this wonderful hobby at a reasonable cost. We also believe working within a community of similar imagers significantly enhances the experience and accelerates the learning process. Who is or isn’t an astrophotographer? Well, we don’t judge. On to more interesting topics!
We’ve even started to take this a step further: for those with “interesting systems” which are desirable to other imagers we’ll host them for free. It’s a play on the sharing economy in a way. The sky isn’t going to change substantively in our lifetimes, but the equipment is changing quickly and not everyone can afford to get the latest greatest thing all the time. Today we have a Rokinon lens (130mm crazy wide field), an FSQ (tried and true), two difficult to get A-P 305s (with 16803 and 8300 chips), an RC Optical 14.5” (3,340mm FL) and an A-P 175 Starfire refractor—another rare instrument. We don’t own all these systems. Some are owned by our members who, in exchange for hosting and support, allow us to open the systems to other members via our shared model. Each of these is interesting in its own way and we’re happy to have them on offer for imagers who’d like to participate in this way. Ours is similar to other services, but we believe we’ve made it more cost-effective and our members are able to work with data integrations of at least 15 hours per target. This varies by instrument, but our goal is quality of images over quantity.
Design. DSW “Alpha” is actually the first of several ”Roll Off Building” (ROB) observatories planned for DSW. We chose the ROB design for several reasons including simplicity, modularity, and durability. Traditional stick-frame construction is a popular design and works well for observatories both large and small. However, for DSW Alpha, Alpha 2.0 and Beta (opening Summer 2017) the Steelmaster arch-style proved the best choice. Steel buildings are simple, modular, durable, water-proof, require little maintenance and are non-combustibleextra bonus for that. The ROB runs on rails similar in design to a rollercoaster. The building is “captured” both above and below tubular rails and is thus able to withstand high wind loads. Our custom designed electric motor and gearing enables the ~2.5-ton structure to be moved with ease. A common garden shed outfitted with wheels would make a fine observatory.
DSW Alpha started as a 25 x 30 foot, 9-pier facility. Alpha 2.0 is the original facility with an additional 25 feet of roof sections and 9 more piers which were installed in the Summer of 2016. The modularity of steel construction allowed us to add roof sections as needed. DSW Beta will follow the same basic design.
Two other design elements play a critical role in the effectiveness of a roll-off building. First is overhead clearance. DSW’s overhead clearance is 9.5 feet and all imaging systems are kept below this level. Roof to scope contact is impossible. When weather conditions demand, the observatory can close without regard for the position of any system. There’s no need for special “at park” sensors or anything similar. When it’s time to close, we close.
The second design element is the inner stub wall system which provides protection from ground-level winds, dust and other unwanted elements. They give the feel of a traditional roll off roof, but are stationary and non-load bearing. The stub walls are convenient for power outlets, flat panels, etc. Some traditional RORs go so far as to motorize the southern wall to increase visibility to the south. At DSW simplicity and reliability go hand in hand so we just limited the southern wall to 4 feet. Southern views go down to the horizon if you want to chase a southerly target.
Redundancy. Every critical DSW subsystem has a backup—especially cloud and rain sensing. We use two Sky Alert cloud sensing systems with automatic failover. We also employ Hydreon optical rain sensors in a redundant arrangement to provide additional rain sensing capability. A Davis Weather Station supplies micro-climate information to the roof actuation system. In all, there are 5 systems that monitor the weather and work together to determine whether or not conditions are safe.
Power is obviously another critical subsystem. We take a very straightforward stance with respect to power availability. If main AC fails, we close and stay closed until we understand the reasons for the failure. Our UPS, which is backed up by charge-managed deep cycle marine batteries, has the ability to actuate the roof and run the imaging systems for several days.
However, to continue to operate on UPS power without knowing the cause of a power outage is unsafe. What if power is down for several days and the UPS and backup batteries are depleted? Now suppose it rains. You get the not very pretty picture. The smart move is to close until the root cause of the power failure is known. This brings us to a discussion of opening and closing protocol.
Protocol. Equipment and infrastructure protection is our primary concern. We’d rather miss a few hours of clear sky before risking the safety of the facility and its contents. As such, we take a conservative approach with respect to observatory opening and closing. DSW is fully autonomous and opens and closes based on inputs from all the various sensing systems. Redundancy and strict adherence to protocol protects the observatory.
The normal open and close cycle for DSW is to open every day one hour before dusk and to close 30 minutes after sunrise. The time between opening and astronomical dusk allows the systems time to reach thermal equilibrium and to perform other functions like flat acquisition. The protocol for opening and closing depends on several factors. DSW opens at the appointed time only if main AC power is active, WAN/LAN is functioning, and the weather is clear. The definition of “clear” is a function of the difference between the ambient temperature and the sky temperature. The latter is measured by infrared sensors on the Sky Alert system. If “clear” is detected and all other conditions are met, then the observatory opens for business. The operators, technicians and residents are notified via email and/or text messages anytime the roof opens or closes and the reason for the movement.
For example, our favorite message is “Email #1 – DSW1 – Opening Beginning of Session”. Conversely, our least favorite message is “Email #9 – DSW1 – Not Opening at Sunset Due to Weather”. This disappointment is easily reversed when we receive “Email #8 – DSW1 – Re-Opening After Weather Event”.
If at any time during the night any of the safe conditions change then the observatory closes and notifies everyone about the closure and the reason. The observatory will re-open if safe conditions hold for at least 30 minutes. The most common cause of closure is sky conditions changing from clear to cloudy to “very cloudy”. In anticipation of potential rain or other precipitation the observatory will close until the danger passes. Other closure conditions for DSW include humidity >= 80%, wind >= 12 MPH, unstable or vacillating weather conditions.
Support. All observatories require technical support whether they’re in a backyard or far from home. Remote observatories present a particular challenge for the obvious reasons: you can’t touch your system and depending on the infrastructure you might not even be able to see it! Competent, local support is critical. Well-designed redundant systems help tremendously, but nothing replaces real human interaction. At DSW we have several support personnel with various areas of expertise including infrastructure, network and imaging system operations.