Don Petravick, Eileen Berman, Donald Holmgren, Chih-Hao Huang, Tom Nicinski, Ruth Pordes, Ron Rechenmacher, Gary Sergey, Chris Stoughton Computing Division, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, Illinois 60510, United States of America Robert H. Lupton Astrophysics Department, Princeton University Observatory, Peyton Hall, Ivy Lane,Princeton, New Jersey 08544, United States of America
AbstractThe Sloan Digital Sky Survey is a collaboration between the Fermi National Accelerator Laboratory, the Institute for Advanced Study, The Japan Promotion Group, Johns Hopkins University, Princeton University, The United States Naval Observatory, the University of Chicago, and the University of Washington. The SDSS will produce a five-color imaging survey of 1/4 of the sky about the north galactic cap and image 10^{8} Stars, 10^{8} galaxies, and 10^{5} Quasars. Spectra will be obtained for 10^{6} galaxies and 10^{5} Quasars as well. The survey will utilize a dedicated 2.5 meter telescope at the Apache Point Observatory in New Mexico. Its imaging camera will hold 54 Charge-Coupled Devices (CCDS). The SDSS will take five years to complete, acquiring well over 12 TB of data.
The SDSS Collaboration involves upwards of 50 scientists, many of whom are involved in the development and use of the software needed to acquire, process and archive the image and spectroscopic data sets. Fermilab has major responsibilities in the development and maintenance of the project's software and for its software engineering practices. We report on the standards and methodologies we have developed in support of these activities.
At the beginning of the project we launched a concerted effort to establish a base line for standards and methodologies in support of the software development activities - the details of which were reported at Chep in 1994.
These practices were then ratified by the project at large and have been used and extended significantly. Through two years of development and support we have successfully organized the development of greater than 200,000 lines of source, and integration of more than one million lines before the start of data taking. We successfully orchestrate centralized integration at Fermilab of software developed over six physically separate institutions.
The survey continues to follow the spirit of the POSIX standards, and to incorporate them to the greatest extent feasible. ANSI-C, Extended F77 and C++ are the allowed programming languages. We include much public domain software into our central code repository and support infrastructure. As reported previously, other software standards in use are: X11, WWW and HTML, perl, TeX, CVS and RCVS, Fermilab UPS, tcl/tk, and an Object-Oriented Database for the survey's DBMS.
In this paper we report on our experiences and the perceived benefits in using and "enforcing" these standards. We report on further developments and directions we are taking for organizing and managing the software of the survey. In particular, we are now placing emphasis on developing tools for quality control and analysis and we present details of our tools and methods in these areas. The successful implementation and adoption of our methodologies within the collaboration gives us the confidence that new tools we develop can and will be applied to good effect across the breadth of the collaboration's software.