Evaluation of the HALAS System: A Comparative Analysis with Radiosonde and Microwave Radiometer Observations

This study presents an intercomparison between the High Altitude LiDAR Atmospheric Sensing (HALAS) system and two conventional observing methods. During a 96-day observation period in the summer of 2024 at the National Weather Service Sterling Field Support Center (SFSC), the HALAS system reported temperature, relative humidity, and horizontal wind through the atmosphere’s vertical column. Data from the HALAS system were compared to radiosonde measurements from the Sterling Weather Forecasting Office and observations from the MP-3000A microwave radiometer at SFSC. Radiosonde observations serve as a reference to quantify the accuracy of the HALAS system across all variables, while microwave radiometer data provides a comparison of water vapor profiles between this widely used remote sensing system and HALAS. Mean and variance statistics are used to evaluate trends and performance for each observing system, as well as to provide a detailed analysis of the HALAS system accuracy. This intercomparison highlights the HALAS system’s capabilities and alignment with two established atmospheric measurement techniques.