Improving safety in cities by using GNSS stations to monitor precipitable water vapor with the PPP method

Abstract

Sustainable cities are urban environments designed and developed to promote economic, social and environmental well-being. Climate monitoring plays a vital role in achieving sustainable cities, providing essential data and insights for effective planning, decision-making and strategy implementation. Flooding is a recurring factor in urban areas, necessitating measures to monitor it. Precipitable water vapor (PWV) is a highly variable component and is a parameter for understanding moisture availability and its relationship with precipitation. Different techniques have been developed to estimate and monitor water vapor. Currently, the Global Navigation Satellite System (GNSS) has stood out in the estimation of PWV, due to its high precision and resolution, its cost and the possibility of monitoring. In this work, the Precise Point Positioning (PPP) method was used in near-real time, through the tropospheric delays of five stations in the Brazilian GNSS network, located in different regions, in cities that are frequently affected by heavy rainfall, to calculate PWVs, in order to prove the efficiency of using GNSS. The IBGE's post-processed PPP data was used as a reference for evaluating the results and then analyzing the accuracy. The results proved to be satisfactory for the purpose and consolidate it as a fundamental tool for urban environments to monitor weather events in almost real time.