Precipitable water vapor measurement using GNSS data in the Atacama Desert for millimeter and submillimeter astronomical observations

The precipitable water vapor (PWV) strongly affects the quality of data obtained from millimeter- and submillimeter-wave astronomical observations, such as those for cosmic microwave background (CMB) measurements. In this presentation, I will introduce the PWV measurement method using Global Navigation Satellite System (GNSS). Compared to other PWV measurement methods, GNSS instruments are robust in bad weather conditions, have sufficient time resolution, and are less expensive. By demonstrating PWV measurements with good accuracy using GNSS instruments in the Atacama Desert, which has low PWV conditions, I will show that GNSS instruments are valuable tools for PWV measurements for observing site evaluation and data analysis for ground-based telescopes.