SNARF Working Group - Report of the Second SNARF Workshop

Eos Trans. AGU, 85(17), Jt. Assem. Suppl., Abstract G21D-06, 2004

Application of a North America Reference Frame to Regional GPS Arrays in the Deforming Plate Boundary Region: Examples From the Pacific Northwest Geodetic Array (PANGA)

Miller, M
Email: meghangeology.cwu.edu
Address: Central Washington Univeristy, Geodesy Laboratory,
Ellensburg, WA 98926 United States

Santillan, V M
Email: vmarcellogeology.cwu.edu
Address: Central Washington Univeristy, Geodesy Laboratory,
Ellensburg, WA 98926 United States

Johnson, D J
Email: djohnsonuwash.edu
Address: University of Washington, Earth and Space Science,
Seattle, WA 98195 United States

Global and regional solutions for GPS (Global Positioning System) networks are typically analyzed in the International Terrestrial Reference Frame (ITRF), derived from a mathematically powerful and self-consistent reference system that, for non-specialists, is non-intuitive and poorly understood. Such regional solutions in the ITRF can then be transformed into "stable plate" or other physically meaningful reference frames, either by using published Euler vectors that describe plate motions in the ITRF or by including stations in an analysis that can be used to define a "rigid" plate or block. The PANGA network has used this latter technique to define a GPS determined "North America" reference frame through several generations of solutions. Our approach consists of generating fiducial-free, ambiguity resolved daily solutions that are stabilized to ITRF2000 using JPL data products such as fixed orbits, fixed clocks, and daily frame files. These are then stabilized to a reference file in ITRF2000 that also contains regional stations with well-determined linear velocities. This results in negligible change in velocities but much greater resolution of the time series. Finally, the ITRF velocities are stabilized to a subset of stations that may characterize a more stable continental interior. We explore the stability of this reference frame over annual solutions generated since 2000. Enhancements to the data analysis strategy, a more robust set of stations from the continental interior, better regional GPS coverage, and concomitant improvements in precision improve resolution of time series but have little effect on stability of the reference frame at the millimeter level. We propose approaches for optimization of a Stable North America Reference Frame (SNARF) that will provide a plate scale regional stabilization, steps towards a physically meaningful reference frame, and better resolution of time series.

Last modified: 2019-12-24  02:12:53  America/Denver