Point Positioning Service for Natural Hazard Monitoring

Abstract:

In an effort to improve natural hazard monitoring, JPL has invested in updating and enlarging its global real-time GNSS tracking network, and has launched a unique service – real-time precise positioning for natural hazard monitoring, entitled GREAT Alert (GNSS Real-Time Earthquake and Tsunami Alert).

GREAT Alert leverages the full technological and operational capability of the JPL’s Global Differential GPS System [www.gdgps.net] to offer owners of real-time dual-frequency GNSS receivers:

• Sub-5 cm (3D RMS) real-time, absolute positioning in ITRF08, regardless of location
• Under 5 seconds turnaround time
• Full covariance information
• Estimates of ancillary parameters (such as troposphere) optionally provided

This service enables GNSS networks operators to instantly have access to the most accurate and reliable real-time positioning solutions for their sites, and also to the hundreds of participating sites globally, assuring inter-consistency and uniformity across all solutions. Local authorities with limited technical and financial resources can now access to the best technology, and share environmental data to the benefit of the entire pacific region.

We will describe the specialized precise point positioning techniques employed by the GREAT Alert service optimized for natural hazard monitoring, and in particular Earthquake monitoring. We address three fundamental aspects of these applications: 1) small and infrequent motion, 2) the availability of data at a central location, and 3) the need for refined solutions at several time scales