Estimation of Excess Electrical Path Length by Water Vapour Radiometry
Year: 2026
Type: conference-paper
Abstract: This paper presents an improved estimation method for excess electrical path length induced by atmospheric water vapour using dual-frequency microwave radiometry. Atmospheric water vapour introduces a significant delay in geodetic measurements such as VLBI, GPS, and microwave remote sensing. A dual-frequency approach at 30 GHz and 28.834 GHz is adopted to separate the contributions of liquid water present in the cloud and water vapor with enhanced accuracy. Radiative transfer modelling was utilized to determine attenuation and associated path delay using radiometric brightness temperature data from the MP-3000A microwave profiler at Fortaleza, Brazil. Results show that the excess wet delay varies between 0.85 and 1.15 cm during the rainy season, demonstrating the applicability of the chosen frequency pair and the robustness of the retrieval algorithm for tropical environments. The proposed methodology supports high-precision atmospheric correction for geodesy, propagation studies, and microwave communication links.
Institution: Guru Nanak Institute of Technology
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: hybrid
OpenAlex ID: W7203750155