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Vertical Land Motion Global Navigation Satellite System (GNSS) Campaigns, Southeast Virginia, 2018 to 2020

February 4, 2022

This data release is a compilation of annual Global Navigation Satellite System (GNSS) surveys of a network of 26 vertical control points (benchmarks) in the Hampton Roads region of southeastern Virginia. Surveys are conducted annually during the winter and are structured to collect a minimum of 24 hours of position data when possible at an interval of 15 seconds or less at each benchmark location. Raw GPS survey files are downloaded and converted to Receiver Independent Exchange Format (RINEX) and post processed using the National Oceanic and Atmospheric Administration (NOAA) National Geodetic Survey (NGS) Online User Positioning Service (OPUS) Projects 4.12 software package following guidance and best practices from the NGS. The results files summarize the annual ellipsoid heights, in meters, and associated metadata for each benchmark surveyed for that year. Ellipsoid heights are referenced to the International Terrestrial Reference Frame 2014 (ITRF2014) at epoch 2010.000 and the epoch effective at the time of data collection. Raw GNSS observation data from seven (7) of the benchmarks are collected by collaborating federal agencies using consistent techniques, methods, and equipment where possible, and provided to the USGS for inclusion in the study. A new results file and associated RINEX files will be added each year during the duration of the project once the most recent results are finalized.