Title: GNSS H2O: A Global Network of In Situ Hydrologic Sensors Derived from GNSS Data
Presenting Author: Susan Owen
Organization: Jet Propulsion Laboratory

Abstract:
GNSS instruments are routinely used by surveyors to measure land boundaries and by geophysicists to monitor tectonic motions. These GNSS instruments can also provide valuable and cost-efficient information about soil moisture, snow depth/snow water equivalent, vegetation water content, and water levels. A pilot project in the western U.S. (PBO H2O) has demonstrated that GNSS hydrologic data can be produced operationally in a time scale that is relevant for weather forecasting, climate studies, and satellite validation. Some of the 10,000+ continuously-operating GNSS sites that currently exist globally could be generating hydrologic and water level measurements at minimal cost, but information technology limitations preclude expansion from the current system. To build this global network of in situ water sensors, GNSS H2O, we have advanced the technology of software that acquires and processes GNSS data from disparate and variable sources. We have developed technology that 1. Enables operators of GNSS networks to provide metadata regarding their stations and data archives to the GNSS H2O system. 2. Evaluates the site characteristics of a station or proposed station, by determining the close proximity of roads and other factors that would render the data unusable for hydrologic products. 3. Leverages the proven Apache OODT framework to enable generalization and scalability of the hydrologic calculations.