Astronomers store their data in a generally agreed format, called FITS. The acronym FITS stands for Flexible Image Transport System. FITS is much more than an image format (such as JPG or GIF) and is primarily designed to store scientific data sets consisting of multi-dimensional arrays (1-D spectra, 2-D images or 3-D data cubes) and 2-dimensional tables containing rows and columns of data.
The low level data from the SDSS project (like spectra and our basic images, called corrected frames) are stored as gzip-compressed FITS files, accessible through a URL from our Data Archive. We have also built several functions in the database to compose the URLs of the FITS files directly from the object catalog.
Spectrum FITS file: Download