New Positioning Products and Pilot Service for Natural Hazard Monitorin

Abstract:

We describe a new pilot service from JPL’s Global Differential GPS (GDGPS) System that provides positioning solutions for hundreds of GNSS tracking sites, from both global and regional networks, aiming to monitor ground motion in the immediate aftermath of earthquakes. The new service provides site position time series solutions at 1 Hz, based on GNSS tracking data. Recognizing the tradeoff between latency and accuracy, the solutions are provided at multiple latencies, ranging from one second to one hour. Individual site solution accuracy strongly depends on the local tracking data. The median site position accuracies ranges from ~one cm 1DRMs for the to most latent solution to ~five cm 1DRMS for the one-second solutions.

We discuss the tradeoff between accuracy and latency and explain the choice of product latencies in terms of this trade and in terms of the benefits to agencies responsible for issuing alarms and managing natural disasters. We describe and demonstrate a simple user algorithm to seamlessly merge the disparate latent solutions into a single, optimal record of site motion.

The positioning service is integrated with automated earthquake notices from the USGS to support calculations of co-seismic displacements.

Finally we describe the current scope of the pilot project, its innovative user-interface, and our ultimate plans to serve all real-time GNSS sites.