Principal Investigator (PI): Charles Meertens, UNAVCO
The problem addressed by this project can be explained by the following scenario: Suppose a group of scientists in Africa would like to install a GPS receiver to study volcanic activity in the East Africa Rift, adding significant extra value to existing seismometers of the newly developing AfricaArray. These scientists are growing experts on the East Africa Rift and at modeling volcano deformation, but have little expertise in geodesy, which they perceive as a barrier to proposing their idea, and to carrying the project to its full potential should they get funding. As a consequence, their proposal is either not written or is declined, the GPS receiver is never installed, scientific progress in understanding the East Africa Rift is impeded, the hazards from volcanoes are not mitigated, and there is a missed opportunity for scientific capacity building in a developing region. There are so few instruments in Africa, the whole world (not just scientific community) loses in this scenario.
The vision of this project is that if scientists in this scenario can point to UNAVCO in their proposal, and register their station with UNAVCO, it is guaranteed that within 1-2 hours of installation, they (and the whole world) will have access to 5-minute time series of GPS coordinates at the centimeter level. Their proposal is accepted, and everybody wins. And as a further consequence of this success, NASA has strengthened its ties and opportunities for partnerships in the developing world, reducing the barriers to scientific access in relatively unexplored regions of our planet.
How can this work? Recent NASA technology makes this not only possible, but also relatively easy to implement by those who know how. We leverage two existing technological capacities already developed and funded by NASA with the highest technological readiness level: (1) the UNAVCO data archive system and associated Geodetic Seamless Archive Centers that provides data access and includes the ingestion and formatting of GPS data; (2) the University of Nevada, Reno operational system that already produces 5-minute GPS time series for over 2,000 stations with centimeter-level precision with 1-2 hour latency. The UNR system currently picks up hourly data files from the UNAVCO archive, and processes the data using NASA-funded technology and products developed at NASA's Jet Propulsion Laboratory (JPL), including ultra-rapid GPS orbits and clock parameters, and JPL’s Global Navigation Satellite System (GNSS)-Inferred Positioning System and Orbit Analysis Simulation Software (GIPSY OASIS II) software. The UNR system is hands-off, automatically every hour processing 30-hour batches of data from each of hundreds of stations around the globe, with hourly updates to provide the best possible time series at any given point in time. What UNR requires is accurate metadata in the data file headers, something that UNAVCO can insure by a process of registration and approval from newly proposed stations. UNAVCO in turn would be the natural gateway for public access to these products in the most scientifically useful form.
From the point of view of the scientists in Africa, a GPS receiver can be plugged in, and a suite of products are played back to them. These products will include flexible, easy to navigate, graphic, map-based and text based products the allow the users to quickly find the information they want for point positions, time series, velocity, and strain rate fields. This is plug and play GPS for Earth scientists. We have NASA technology ready to do this now.
In addition, to facilitate scientific networks in developing areas of the world, this project will work with specifically targeted users to fine tune the form of the products so that they can be of maximum utility to experts in the rapid modeling and analysis of natural hazards. Groups that have been identified include the QuakeSim Project, GPS Real-Time Earthquake and Tsunami (GREAT) Alert Project coordinated at JPL, the USGS Volcano Hazards Center, and of course, AfricaArray.