Sierra Remote Observatories

Introduction

Sierra Remote Observatories (SRO) is a dedicated site for state-of-the-art robotic/remote astronomical data acquisition and imaging.  We are uniquely located in the center of California's Sierra Nevada Mountains, about 50 miles South of Yosemite National Park and 50 minutes from the Fresno-Yosemite International Airport by car.  In addition to having excellent darkness and seeing, SRO’s location is unique in being within an hour of a major metropolitan area and international airport, making access to the facility and to expert personnel unusually easy.   At nearly 5000 feet, on top of Bald Mountain, the site was chosen for its excellent seeing condition and accessibility.  Summer intrinsic seeing quality FWHM measures 1.0 arcsecond.  The site is very dark at 21.78-22 magnitudes/sq arcsecond.  With excellent seeing, an extremely low incidence of thunderstorm activity, maximum wind gusts averaging only 10 mph, on-site services, an average of 237 photometric nights each year and easy access, Sierra Remote Observatories offers the professional scientist and amateur imager an excellent imaging location.

Facilities
Since first light in May of 2007, SRO has continuously operated multiple roll off roof observatories for both professional research and amateur imaging. 
There are 8 individual observatories which each house one or more telescopes and larger observatories which each contain 14-16 telescopes of various sizes, ranging from a 28” RCs to smaller refractors.  The larger observatories are uniquely designed with 9-10 foot ceilings, making any contact of the ceiling and telescope virtually impossible, regardless of the position of the telescope. The operation of the roof in each building is automated and will close under any adverse weather conditions.  Custom clamshell dome observatories for 1 meter class telescopes have been designed and can be made available within 3-6 months of request.
One of the important features of our facility is directly related to our location.  The ease of access for SRO is unique.  We are 50 minutes from the Fresno-Yosemite International Airport, by car.  At 4610 feet we are above the central valley inversion layer, but not so high as to impede winter access.  We do see snow in the winter, but generally it melts after most storms, simplifying access.  Being close to a major metropolitan area we are afforded fiber optic internet, with download and upload speeds of 100 Mbits/sec (full duplex) and up to 2.5 Gbps speeds available.  Additionally, we have over a dozen fiber optic cables available if our bandwidth is exceeded by use. 
Of note, we are located along the first western edge bluffs of the Sierra Nevada Mountains and the air over SRO appears to be relatively laminar as opposed to the more turbulent air at higher elevations, accounting for our excellent seeing conditions.  Because we are relatively close to Fresno, clients have access to the numerous amenities and technical services which only a large metropolitan area can offer.  Additionally although close to the Fresno area, the unique geography of our location results in our site remaining quite dark at 21.78 to 22 magnitudes/square arcsecond.   
Infrastructure
A sound infrastructure is critical to the smooth operation of SRO.  It enables our clients to focus on data acquisition, knowing there will be no difficulties accessing their equipment or downloading data in addition to knowing their telescopes will be protected from expected or unexpected changes in weather conditions. 
SRO has on-site technical support with most problems repaired on site within 24-48 hours, with emergency services available whenever necessary.  Machine shop services and on-site technical personnel for repairs are available.         
All the observatories are constructed with elevated wood sub floors, designed to minimize thermal contamination.
Internet is fiber-optic and SRO’s optical fiber connection has downloading and uploading speeds of up to 100 Mbps, full duplex, unusual for most remote imaging sites.
 SRO uses an intelligent roof management system based on the commercially distributed ‘m1OASYS’ roll-off roof controller and a custom developed roof management application that monitors real-time weather conditions and responds accordingly.  The application will open or close an individual roof in response to changing weather conditions.  Weather is monitored at the SRO site via a number of weather telemetry capture devices and data fed to the real-time roof monitoring app via the site communications network.  Current weather conditions are then evaluated once each second for any kind of actionable roof event such as changes in cloud cover, humidity, dew levels, or precipitation. 
Should an actionable weather change be detected, the roof will then be closed to protect client equipment from any kind of adverse conditions.  Improvements in weather are also monitored in real-time and once good observing conditions have been re-established, the roof will be re-opened to provide optimal client access to productive observing time.  To ensure reliability, critical infrastructure components are backed up with multiple devices and SRO building design is such that a roof can be closed with scopes and equipment in any position.  In addition there is an emergency back-up rain detection system that will bypass the computerized root management system in the event of a software failure to detect worsening weather conditions.
 
Our Clients
Our clients include Professional Astronomers, Space Industry Professionals, Universities and Astronomical Institutes and Astrophotographers.