The basic characteristics of the LSST facility derives directly from its science programs. The telescope itself must have a wide field of view in order to obtain several hundred images of each area of the sky over an entire hemisphere in only 10 years. The aperture must be large in order to achieve the sensitivity required to reach faint limiting magnitudes. The wavelength coverage must be broad in order to derive photometric redshifts and to characterize the ages and metallicities of stellar populations. The telescope must be located at a site with a very high percentage of usable nights distributed reasonably uniformly throughout the year. Terabytes of data must be obtained every observing night and reduced in near real time in order to keep pace with the data flow and to send out alerts within a minute or so of detections of interesting changes in brightness. The raw images must be converted to well-calibrated data products that can be used by a broad community. The challenge of the systems engineering program is to translate these general science requirements into quantitative technical specifications for the LSST telescope, camera, and data management systems and to flow down the requirements to each component of these major subsystems. See more about the system design flow [PDF 660 kb].
The three subsystem teams have generated the LSST baseline design from the technical specifications. The resulting baseline design will perform all of the science reference missions. c and provides a basis for the Project Execution Plan. We will continue to improve the design during the remainder of the design and development phase. At the same time, however, we are committed to holding mission scope constant and remaining within the current cost envelope while we work to enhance performance.
Download the System Design Document [PDF, 6.8 MB].
This Document begins with a description of the observatory site (Section 4.1.1) and optical design of the telescope (Section 4.2). Subsequent sections deal with the three major subsystems: the telescope (Section 4.3), camera (Section 4.4), and data management (Section 4.5) systems.
The LSST Observatory "complex" is distributed over four sites: the Summit Facility, the Base Facility, the Archive Center, and the Data Centers. Table 4-1 in the above document lists the location, features, and function of each site, and the LSST team responsible for the subsystem components at each site. Although the four facilities are distributed geographically, they are functionally connected via dedicated high-bandwidth fiber optic links. Real-time transient alerts will be broadcast over the Internet within one minute of data collection. Digitally processed images and feature catalogs will be available to the U.S. community via the Internet within 24 hours. All four observatory sites are integrally related and functionally part of this process.
