As the world-leading submillimeter telescope, the Atacama Large Millimeter/submillimeter Array observatory is now putting more focus on high-frequency observations at Band 7–10 (frequencies from 275 to 950 GHz). However, high-frequency observations often suffer from rapid variations in atmospheric opacity that directly affect the system temperature
Tsys. Current observations perform discrete atmospheric calibrations (Atm-cals) every few minutes, with typically 10–20 occurring per hour for high frequency observation and each taking 30–40 s. In order to obtain more accurate flux measurements and reduce the number of atmospheric calibrations (Atm-cals), a new method to monitor Tsys continuously is proposed using existing data in the measurement set. In this work, we demonstrate the viability of using water vapor radiometer (WVR) data to track the Tsys continuously. We find a tight linear correlation between Tsys measured using the traditional method and Tsys extrapolated based on WVR data with scatter of 0.5%–3%. Although the exact form of the linear relation varies among different data sets and spectral windows, we can use a small number of discrete Tsys measurements to fit the linear relation and use this heuristic relationship to derive Tsys every 10 s. Furthermore, we successfully reproduce the observed correlation using atmospheric transmission at microwave modeling and demonstrate the viability of a more general method to directly derive the Tsys from the modeling. We apply the semi-continuous Tsys from heuristic fitting on a few data sets from Band 7 to Band 10 and compare the flux measured using these methods. We find the discrete and continuous Tsys methods give us consistent flux measurements with differences up to 5%. Furthermore, this method has significantly reduced the flux uncertainty due to Tsys variability for one data set, which has large precipitable water vapor fluctuation, from 10% to 0.7%.