Safeguarding astronomical research: innovative and traditional techniques for rainwater leak detection in telescope observatories

Ground-based telescope observatories are typically located in harsh environments. Due to their location, they are subject to a wide range of severe environmental conditions such as seismic events, strong winds, and large diurnal temperature swings including freeze/thaw cycles. It is common for telescope observatories to experience fatigue and degradation as a result of their unique dynamic use within these harsh environmental conditions. One specific result of this degradation includes rainwater leakage into the rotating telescope enclosure. This water leakage has the potential to cause serious damage to interior components of the telescope enclosure, including the telescope and its sensitive instruments. Innovative techniques for detecting rainwater leakage include the use of a thermal imaging camera in conjunction with an Unmanned Aircraft System (UAS) / drone. Standard RGB photography accompanies thermal integrated analysis to allow a non-invasive peer into the health of the telescope enclosure. The drone and its specialized camera capture visual data to identify any abnormality found and cross reference the thermal anomaly to a physical place on the structure. Traditional techniques used for detection include trained and experienced personnel physically observing the structure alongside the data captured by the drone. Using the 8.2-meter Subaru Telescope on Maunakea in Hawaii as a case study, this paper will present innovative and traditional techniques for detection of rainwater leakage into the rotating telescope enclosure and other sensitive areas. The Subaru Telescope was constructed in the late 1990’s and is starting to experience predictable degradation of the rotating enclosure after 20+ years of use on Maunakea. By utilizing innovative and traditional techniques for rainwater leak detection, the Subaru Telescope will be able to better identify problem areas and start to repair these areas to prevent further degradation. Lessons learned from the experience will better prepare Architects and Engineers for the design of future ground-based telescope observatories.