A stable reference frame for landslide monitoring using GPS in the Puerto Rico and Virgin Islands region

Global Positioning System (GPS) technologies have been frequently applied for the purpose of landslide monitoring. A local stable reference frame is essential for precisely interpreting landslide movements derived from GPS observations. In this study, we define a stable reference frame using over 5 years of continuous GPS data collected from eight permanent GPS stations in the Puerto Rico and Virgin Islands (PRVI) region. The realization of the Stable Puerto Rico and Virgin Islands Reference Frame (SPRVIRF) is defined in terms of a 14-parameter Helmert transformation from the International Global Navigation Satellite System (GNSS) Service Reference Frame of 2008 (IGS08). SPRVIRF is aligned with the IGS08 at epoch 2013.0. The GIPSY/OASIS (V6.2) software package, which employs the precise point positioning (PPP) with single receiver phase ambiguity resolution, was used to calculate position coordinates within IGS08. Through the combined use of the PPP post-processing method and SPRVIRF, it is practical and easy to conduct millimeter accuracy landslide monitoring by a single technician with a single GPS unit. SPRVIRF provides a precise common reference frame in the PRVI region that can be used for a broad range of research applications, such as delineating long-term landslide creeping, studying ground deformation associated with subsidence, fault creep, hydrologic loading and microplate motions, and monitoring long-term deformation of critical structures, such as dams, high-rise buildings, and long-span bridges.