The New Solar Telescope (NST) is a 1.6-meter off-axis Gregory-type telescope with an equatorial mount and
an open optical support structure. To mitigate the temperature fluctuations along the exposed optical path,
the effects of local/dome-related seeing have to be minimized. To accomplish this, NST will be housed in a
5/8-sphere fiberglass dome that is outfitted with 14 active vents evenly spaced around its perimeter. The 14
vents house louvers that open and close independently of one another to regulate and direct the passage of air
through the dome. In January 2006, 16 thermal probes were installed throughout the dome and the temperature
distribution was measured. The measurements confirmed the existence of a strong thermal gradient on the order
of 5° Celsius inside the dome. In December 2006, a second set of temperature measurements were made using
different louver configurations. In this study, we present the results of these measurements along with their
integration into the thermal control system (ThCS) and the overall telescope control system (TCS).
The New Solar Telescope (NST) is an advanced solar telescope at Big Bear Solar Observatory (BBSO). It features a 1.6-m clear aperture with an off-axis Gregorian configuration. An open structure will be employed to improve the local seeing. The NST Telescope Control System (TCS) is a complex system, which provides powerful and robust control over the entire telescope system. At the same time, it needs to provide a simple and clear user interface to scientists and observers. We present an overview of the design and implementation of the TCS as a distributed system including its several subsystems such as the Telescope Pointing and Tracking Subsystem, Wavefront Sensing Subsystem etc. The communications between different subsystems are handled by the Internet Communication Engine (Ice) middleware.
We present the basic design of the THermal Control System (THCS)
for the 1.6-meter New Solar Telescope (NST) at the Big Bear Solar
Observatory (BBSO), California. The NST is an off-axis Gregorian
telescope with an equatorial mount and an open support structure.
Since the telescope optics is exposed to the air, it is imperative
to control the local/dome seeing, i.e., temperature fluctuations
along the exposed optical path have to be minimized. To accomplish
this, a THCS is implemented to monitor the dome environment and
interact with the louver system of the dome to optimize instrument
performance. In addition, an air knife is used to minimize mirror
seeing. All system components have to communicate with the
Telescope Control System (TCS), a hierarchical system of computers
linking the various aspects of the entire telescope system, e.g.,
the active mirror control, adaptive optics, dome and telescope
tracking, weather station, etc. We will provide an initial
thermal model of the dome environment and first measurements taken
in the recently replaced BBSO dome.
The New Solar Telescope (NST) project at Big Bear Solar Observatory (BBSO) now has all major contracts
for design and fabrication in place and construction of components is well underway. NST is a collaboration
between BBSO, the Korean Astronomical Observatory (KAO) and Institute for Astronomy (IfA) at the University
of Hawaii. The project will install a 1.6-meter, off-axis telescope at BBSO, replacing a number of older solar
telescopes. The NST will be located in a recently refurbished dome on the BBSO causeway, which projects
300 meters into the Big Bear Lake. Recent site surveys have confirmed that BBSO is one of the premier solar
observing sites in the world. NST will be uniquely equipped to take advantage of the long periods of excellent
seeing common at the lake site. An up-to-date progress report will be presented including an overview of the
project and details on the current state of the design. The report provides a detailed description of the optical
design, the thermal control of the new dome, the optical support structure, the telescope control systems, active
and adaptive optics systems, and the post-focus instrumentation for high-resolution spectro-polarimetry.
The New Solar Telescope (NST) is an innovative 1.6-meter, off-axis, open telescope currently being developed and built at the Big Bear Solar Observatory (BBSO). The observatory is situated on a small peninsula in Big Bear Lake, a mountain lake at an altitude of about 2100 m in the San Bernardino Mountains of Southern California. The lake effectively suppresses the boundary layer seeing. Thus, providing consistently very good daytime seeing conditions. BBSO has been identified by the site survey for the Advanced Technology Solar Telescope (ATST) as one of the best sites for solar observations. It is uniquely qualified for long-duration observations requiring high-spatial resolution. This type of observations is typically encountered in solar activity monitoring and space weather forecast. The ATST site survey has collected more than two years of data linking seeing conditions to geographical parameters and local climate. We have integrated these data in a MySQL database and we will use this information in connection with a real-time seeing monitor and weather station to predict the seeing conditions at Big Bear such that scheduling and prioritization of observing programs (e.g., synoptic vs. high-resolution modes) becomes possible.