Accessing data

Accessing data products generated by the LSST Software Stack

Most of the data generated by the LSS are in the form of either calibrated images (including coadded images) or tables containing properties of each measured source. While these are stored locally in FITS files, it is not advised that these data be extracted using standard approaches such as PyFits. This is because the FITS files contain metadata that needs to be properly loaded for the contents to be meaningful. Instead, the LSS has its own means of accessing this data, known as the Data Butler (or just simply, the "Butler"). This page describes how to use the Butler to access data generated by the LSS.

This guide assumes you have run the LSS up to and including imageDifference.py. Most of what is described here is based on this tutorial.

Measurements output by the stack