Online soil moisture retrieval and sharing using geospatial web-enabled BDS-R service

• Online soil moisture retrieval and sharing.
• Can be extended for any GNSS-R signal and any soil moisture retrieval algorithm.
• Make continuous spatial–temporal observation of soil moisture possible.

Global navigation satellite system-reflectometry (GNSS-R) signals have recently being used in the monitoring of soil moisture (SM) due to their high availability and widespread existence. GNSS-R signal-based online SM retrieval and real-time product sharing has advantages over other methods because it features the instant and automatic retrieval of SM, and low-latency SM product publishing and sharing, enabling a notable decrease in human and material resource consumption and a timely SM product delivery; however, prior to this manuscript, there has not been a study describing how to do it. This paper uses one type of GNSS-R signals, the Beidou navigation satellite system-reflectometry (BDS-R) signal, as the data source and proposes a geospatial web-enabled BDS-R (GWEB) service. This method tackles the problems of SM retrieval and sharing by implementing the original BDS-R signal publishing, the online SM retrieval, and the SM product sharing. In the GWEB service, a web processing service is adopted to encapsulate the SM retrieval algorithm, and a sensor observation service is applied to publish the original BDS-R observations and the SM products. Signals of the Baoxie BDS-R SM monitoring station in Wuhan, China for the period of November 17, 2014 to November 24, 2014 are used as input in the validation experiment, and the SM products are demonstrated in the sharing platform. Meanwhile, the BDS-R derived SM products are compared with the corresponding SM values measured by ground soil hygrometers, indicating the feasibility of the service for online SM retrieval and sharing.