Soil Moisture Retrieval Based on SBAS and BeiDou GEO Signals

In recent years, GNSS reflectometry (GNSS-R) research has mainly been focused on the Global Positioning System (GPS) while the use of Geostationary Earth Orbit (GEO) satellites has received little attention. This paper investigates the GEO satellite-based GNSS-R with a focus on the application of soil moisture retrieval. A new soil moisture estimation approach using GEO signals are proposed, which is termed GEO reflectometry (GEO-R). Two empirical models (linear and second-order) are developed for signal SNR ratio based GEO-R. Experimental datasets collected from different GEO systems were used to evaluate the proposed methods. The results demonstrate that the proposed GEO-R are able to monitor soil moisture reliably under bare soil condition, augmenting GNSS-R through significantly reduced processing complexity and increased temporal coverage.

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