SCEC Award Number 22020 View PDF
Proposal Category Collaborative Proposal (Data Gathering and Products)
Proposal Title NASA Collaborative Proposal: Quantitative assessment of GNSS/InSAR derived velocity and strain rate estimates over Southern California
Investigator(s)
Name Organization
Xiaohua Xu University of Texas at Austin Zhen Liu National Aeronautics and Space Administration David Sandwell University of California, San Diego Alejandro Gonzalez-Ortega Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (Mexico) Katherine Guns University of California, San Diego
Other Participants
SCEC Priorities 1a, 1c, 2a SCEC Groups CXM, Geodesy, SDOT
Report Due Date 03/15/2023 Date Report Submitted 03/28/2023
Project Abstract
 Our 2022 research proposal is composed of two parts. First part is to develop a systematic approach to quantitively assess InSAR time-series products constructed from multiple methods. This part of work is done mainly by Xiaohua Xu at UT Austin with collaboration from Zhen Liu at JPL. The credit of different InSAR products goes to the participants in the Community Geodetic Model (CGM), including Katherine Guns and David Sandwell. The proposed work is aligned with the current efforts toward a consensus CGM, coordinated with proposals #22036, #22037, #22059, #22049, etc. The second part of the proposed investigations is to continue the current campaign survey and InSAR analysis of the Imperial, Cerro Prieto, Tulecheck and nearby faults in the Mexicali region of northern Baja California. These measurements, together with measurements from the newly install continuous GNSS will be archived with the GNSS development under the construction CGM.
Intellectual Merit This project aims to advance our knowledge of the advantage and limitation on using InSAR to derive deformation velocity maps, which is one of the major tasks of constructing the Community Geodetic Model. The extent of the project also targets on what can and cannot be resolved through such practice, and help resolve on-fault and off-fault strain partitioning. As part of the project, we also developed robust uncertainty estimates for InSAR velocities, that will benefit the application to constructing deformation models.
Broader Impacts The results from this project will be used as part of the teaching materials for our annual GMTSAR short course, which involves promotion and support of teaching, training and involves students from underrepresented groups. We also organize field trips to survey monuments over southern and Baja California that have students from US and Mexico in participation.
Exemplary Figure Figure 3. Coherence spectra for InSAR time-series maps constructed using data from two ascending tracks (top) and two descending tracks (bot). Every curve along correlation and wavenumber axes corresponds to a coherence spectrum for a given date in the InSAR time-series.
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