This memo describes the system used to conduct commensal correlator and beamformer observations at the Allen Telescope Array (ATA). This system was deployed for ~2 years until the ATA hibernation in 2011 and was responsible for collecting >5 TB of data during thousands of hours of observations. The general system design is presented and the implementation is discussed in detail. I emphasize the rationale for various design decisions and attempt to document a few aspects of ATA operations that might not be obvious to non-insiders. I close with some recommendations from my experience developing the software infrastructure and managing the correlator observations. These include: reuse existing systems; solve, don't avoid, tensions between projects, and share infrastructure; plan to make standalone observations to complement the commensal ones; and be considerate of observatory staff when deploying new and unusual observing modes. The structure of the software codebase is documented.
Cite
@article{arxiv.1201.5413,
title = {The Allen Telescope Array Commensal Observing System},
author = {Peter K. G. Williams},
journal= {arXiv preprint arXiv:1201.5413},
year = {2012}
}