SCEC Award Number 19046 View PDF
Proposal Category Workshop Proposal
Proposal Title Community Geodetic Model Workshop
Name Organization
Michael Floyd Massachusetts Institute of Technology Gareth Funning University of California, Riverside David Sandwell University of California, San Diego Susan Owen National Aeronautics and Space Administration David Bekaert National Aeronautics and Space Administration
Other Participants Potentially 25 additional participants, expected to include current and previous contributors to the Community Geodetic Model, e.g. Bill Hammond, Jessica Murray, Zhen Liu, Zheng-Kang Shen, Mark Murray, Adrian Borsa, Yuri Fialko, Alejandro Gonzalez Ortega and Eileen Evans.
SCEC Priorities 2a, 1a, 3e SCEC Groups CXM, Geodesy, SDOT
Report Due Date 10/08/2019 Date Report Submitted 11/14/2019
Project Abstract
The SCEC Community Geodetic Model (CGM) has developed over the last few years to form the basis of a regional product of geodetic time series and velocities. Currently we are able to provide time-independent products consisting of merged continuous GNSS time series sourced from several analysis centers, survey GNSS time series reprocessed in rigorous and by CGM contributors, fits and an array ofInSAR velocity map and time series products gathered from researchers in the community. We now need to build towards a consensus on three main topics: (1) How best to merge continuous and survey GNSS time series into one consistent product, including how to estimate secular velocities and non-linear terms; (2) How to merge GNSS and InSAR products to form the final community products, and in which format to store and access these products; (3) How to design an intuitive yet practical web site/service for dissemination of the products, including allowing users to perform basic manipulations of the whole CGM to provide them with the product they need to begin their analyses. This workshop is specifically intended to encourage integration of JPL/NASA scientists, for whom the CGM activities and experiences may serve as a roadmap for integrated continental deformation products in preparation for the NISAR mission, particularly with respect to the format of large products. We encourage attendees who have contributed, are contributing and will contribute combination techniques with a firm commitment to the building and release of final products via a web interface.
Intellectual Merit The Community Geodetic Model Working Group contains many scientists at the forefront of maintaining and developing methods and products in both GNSS and InSAR. Bringing these leaders together to focus their efforts and expertise on the southern California region. The CGM has, to date, produced consensus on the combination of GNSS time series from multiple publicly-available sources and, in doing so, shown how errors in the individual products may be identified and corrected or mitigated. The combination with InSAR and, more recently, the transition from line-of-sight displacement or velocity fields to InSAR time series. New frontiers in the accuracy of geodetic products, such as the implementation of tidal loading effects on InSAR and non-tidal (e.g. hydrological) loading effects on GNSS are also being investigated to allow the SCEC CGM products to be the most rigorous and well-tested geodetic products available. In producing such highly accurate and precise products, the details of processes beyond secular tectonics and motions associated with major events such as earthquakes may be separated and tested. The more we understand about the content of geodetic time series and velocities, the better our opportunity to provide any given researcher the fundamental geodetic product they desire, having had other processes that one might consider "noise" removed, leaving only their desired signal to study.
Broader Impacts The Community Geodetic Model is one of the core Community Models, which SCEC have prioritized to develop and provide for the scientific community and public at large. This CGM Workshop encouraged and supported students, postdocs, researchers, faculty members and others in the wider SCEC community to attend via an open invitation email. Indeed, at least one graduate student and one postdoc presented research on behalf of their labs regarding input for the CGM. Ultimately, we are working towards not only the best and most rigorous products available but to make these easily understood, accessed and potentially used by the public at large, including potential civil policy makers. We expect the products to form the fundamental data basis, and starting point, of many researchers who use geodetic data to study directly or constrain their models. This efficiency of data product generation and accessibility facilitates the advancement of science and hazard assessment alike.
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