Conveners: Jessica Murray, David Sandwell, and Rowena Lohman
Dates: May 30-31, 2013
Location: Vallombrosa Center, Menlo Park, CA
SCEC Award: 13077

OVERVIEW: The goals of the 2013 Community Geodetic Model (CGM) Workshop are (1) to further develop the big-picture plan for generating the CGM including the overall approach and milestones, (2) produce a concrete list of initial tasks with a strategy and timeframe for completing them, (3) identify members of the SCEC community who will actively contribute to model development. This will involve establishing the requirements, for example, with respect to spatial and temporal resolution, for the model as driven by its envisioned applications. Also necessary will be assessments of the achievable level of precision and associated resolving power that are feasible given available data, the possible addition of new data, and the capabilities of approaches for combing GPS and InSAR time series.

Agenda items for the CGM workshop include:

• Develop a list of anticipated applications for the CGM.
• Define the features, spatial and temporal resolution, and precision required for each application.
• Assess what data are available and where more data are needed to meet requirements.
• Evaluate which approaches to GPS and InSAR time series analysis are most appropriate and what assumptions these methods embody.
• Identify best approaches for combining data types and consider how aspects such as weighting, smoothing, or interpolation will contribute to uncertainties.
• Consider whether more research is needed to further develop new approaches and, if so, in what areas.
• Explore strategies for comparing and validating input and methods used in the CGM.
• Solicit ongoing participation by investigators who will contribute and assimilate data analysis and models to produce the CGM.
• Discuss strategies for maintaining the CGM, once developed, as new data become available.

We envision the CGM workshop to include presentations on data analysis methods and anticipated CGM applications, as well as a significant amount of time for discussion. To stimulate dialogue on analysis methods, we propose to assemble a large stack of interferograms prior to the workshop which interested participants can use to produce InSAR time series employing methodology of their choice. Results will be compared at the workshop to identify best practices for development of the full CGM. Synthetic data will also be used to frame a candidate workflow for combining InSAR and GPS data into a time series product and to explore the relative contribution of the two data types to the final product.

To achieve the workshop goals it will be necessary to bring together a diverse but targeted group of scientists representing likely CGM users and those with expertise in geodetic data analysis, integration, and modeling. At the CSM workshop held in October 2012, it became clear that the CGM will be an important resource for the CSM effort and that there is substantial overlap among researchers involved in the CSM and those whom we hope to involve in the CGM. Therefore CGM Workshop in conjunction with the 2013 SCEC CSM Workshop, which will allow us to obtain input from a broad spectrum of potential users on required features of the CGM.

PARTICIPANTS (29 total): Duncan Agnew (UCSD), Scott Baker (UNAVCO), Greg Beroza (Stanford), Roland Burgmann (UC Berkeley), Ksenia Dmitrieva (Stanford), Yuri Fialko (UCSD), Mike Floyd (MIT), Gareth Funning (UCR), Jeanne Hardebeck (USGS), Liz Hearn (USGS contractor), Tom Herring (MIT), Bill Holt (SUNY at Stony Brook), Tran Huynh (USC), Kaj Johnson (Indiana), John Langbein (USGS), Eric Lindsey (UCSD), Zhen Liu (NASA JPL), Rowena Lohman (Cornell), Betsy Madden (UMass), Sally McGill (CSU San Bernardino), Jessica Murray (USGS), Sue Owen (NASA JPL), Fred Pollitz (USGS), David Sandwell (UCSD/SIO), Manoocherhr Shirzaei (ASU), Josh Spinler (U Arizona), Wayne Thatcher (USGS), Xiaopeng Tong (UCSD), and Yuehua Zeng (USGS)

Presentation slides may be downloaded by clicking the pdf links following the title. PLEASE NOTE: Slides are the author’s property. They may contain unpublished or preliminary information and should only be used while viewing the talk.

THURSDAY, May 30, 2013

FRIDAY, May 31, 2013