Timekeeping infrastructure for the Catalina Sky Survey

TL;DR

This paper discusses the deployment of a high-precision GNSS clock and infrastructure for accurate timekeeping in astronomical observations, emphasizing hardware timestamping and addressing challenges in remote environments.

Contribution

It presents a detailed implementation of a stable, high-precision timekeeping system for the Catalina Sky Survey, highlighting solutions for accurate time tagging in remote astronomical facilities.

Findings

Successful deployment of a GNSS clock at a remote site

Improved accuracy in time tagging for astronomical observations

Analysis of NTP limitations in high-precision applications

Abstract

Time domain science forms an increasing fraction of astronomical programs at many facilities. Synoptic and targeted observing modes of transient, varying, and moving sources rely on precise clocks to provide the underlying time tags. Often precision is mistaken for accuracy, or the precise time signals never reach the instrumentation in the first place. We will discuss issues of deploying a stable high-precision GNSS clock on a remote mountaintop, and of conveying the resulting time signals to a computer in a way that permits hardware timestamping of the camera shutter (or equivalent) rather than the arbitrary delays encountered with non-real-time data acquisition software. Strengths and limitations of the Network Time Protocol will be reviewed. Timekeeping infrastructure deployed for the Catalina Sky Survey will serve as an example.