Criteria to start the Legacy Survey of Space and Time

Abstract

This document concisely captures the criteria that must be satisfied to begin regular survey operations for the Legacy Survey of Space and Time (i.e. to begin execution of the planned 10 year survey strategy currently documented in PSTN-056). It is expected that the survey will start in late 2025 1-2 months after the beginning of the formal Operations phase at the completion of construction. The survey can start based on quantitative criteria described herein. The system contribution to the delivered image quality must reliably be better than 0.4$\hbox{$^{\prime\prime}$}$ and the effective survey speed must be 1.01 or better. Both of these are attainable given our experience and knowledge of the current on sky system.