The Large Synoptic Survey Telescope Data Management Overview

The LSST Data Management System (DMS) processes the incoming stream of images that the camera system generates to produce transient alerts and to archive the raw images, periodically creates new calibration data products that other processing functions will use, creates and archives an annual Data Release (a static self-consistent collection of data products generated from all survey data taken from the date of survey initiation to the cutoff date for the Data Release), and makes all LSST data available through an interface that uses community-based standards and facilitates user data analysis and production of user-defined data products with supercomputing-scale resources. This paper discusses DMS distributed processing and data, and DMS architecture and design, with an emphasis on the particular technical challenges that must be met. The DMS publishes transient alerts in community-standard formats (e.g. VOEvent) within 60 seconds of detection. The DMS processes and archives over 50 petabytes of exposures (over the 10-year survey). Data Releases, include catalogs of tens of trillions of detected sources and tens of billions of astronomical objects, 2000-deep co-added exposures, and calibration products accurate to standards not achieved in wide-field survey instruments to date. These Data Releases grow in size to tens of petabytes over the survey period. The expected data access patterns drive the design of the database and data access services. Finally, the DMS permits interactive analysis and provides nightly summary statistics describing DMS output quality and performance.