Health Check Monitor:
Users Guide

The Health Check Monitor has been created to provide quick feedback on the performance of the VLT/VLTI instruments. It is a core tool for the shared Quality Control process (QC).

The Health Check monitor is a component of the real-time QC system. Its other main components are the calChecker (calibration completeness), and the AB product monitors with the complete set of products, QC1 parameters and scores for a given date.

The tool monitors the most relevant instrument components. It extracts QC information from the daily calibration data stream. Some of these calibrations are dedicated as Health Check calibrations, others are part of the routine calibration plan which is driven by science observations.

The Health Check process is fed by calibrations which measure key instrument components ("health check calibrations"). They are taken regularly, in many cases daily. They are pipeline processed by QC Garching by an automatic process which is triggered every hour. The pipelines derive QC1 parameters which are stored in a database. Some more advanced QC1 parameters are derived by post-pipeline QC procedures and added to the database. These most recent values are trended, that means plotted together with a historical data set (often the last 90 days).

The Health Check system

• retrieves the QC information from the QC1 database
• compares the new QC information to existing data (trending)
• scores the new QC information which means that new parameter set is evaluated against configured thresholds.

The trending information comes in graphical form. It is published on the Health Check web site.

A second data set is included here, namely the QC1 parameters as derived from the Paranal on-line pipelines. These data are collected in opslog files and transferred via ftp. They are included here as a fall-back solution in case of problems with data transfer. The Paranal QC1 parameters could differ from the final values as determined by the Garching pipelines because they are derived with default processing values, a static calibration database etc.

The system is set up such that it can react quickly to new QC information. Once per hour there is a scan for new data available for processing. The goal is to have up-to-date Health Check information within an hour. See more under "strategy".

The Health Check system is designed to provide QC information in a fast and condensed form. It is the core tool of the shared QC task.

This documentation describes the basic concepts and components of the Health Check system.