BNO – GGOS Joint Working Group 1.2.2 (with IERS) on
Metrology of Space Geodetic Infrastructure
Chair: Cornelia Eschelbach
Co-Chair: N.N.
IAG Joint Working Group (w/ IERS) 1.2.2: Our group has a new set of terms and we are encouraging new participants in the group. We would encourage participation from any agency or community that is conducting research, improving protocols, or completing field surveys of local ties as sites with various space geodesy techniques present. Our group has representation from all of the techniques and has continued to share improved protocols, technologies, and instrumentation to provide the most accurate tie measurements possible for all sites around the world. We welcome all to share their contributions, especially with local tie data being incorporated into ITRF2020.
Roles/Objectives
• Enhance and improve knowledge of local tie surveys through applied field practice, research, and dissemination of materials developed.
• Share methodology of existing surveys to maintain consistency and improve future results by isolating systematic errors.
• Share results and research internationally to improve protocols and coordinate work.
• Coordinate the collection of local tie survey data results and associated metadata in a consistent fashion.
Committee leads and Membership
https://www.iers.org/IERS/EN/Organization/WorkingGroups/SiteSurvey/sitesurvey.html (To be updated.)
Recent progress/Plans
◦ Improvements made to standardizing report and data submissions of local tie surveys to provide consistency across all agencies. Additional website enhancements for storage of survey data and reports is underway.
◦ Additional standard operating procedures are being written (NGS/USA) to account for new routines and laser tracking instrumentation being used in recent local tie surveys.
◦ Completed and documented work researching site-dependent GNSS antenna calibrations to account for systematic errors and biases.
◦ Local tie surveys recently completed at Table Mountain Geophysical Observatory (Colorado, USA), Midway Naval Research Lab’s Optical Test Facility (Virginia, USA), and the National Radio Astronomy Observatory (Hawaii, USA).
◦ Measurements collected at the Zeppelin Observatory (Svalbard, Norway)
◦ Upcoming surveys planned at National Radio Astronomy Observatory (New Mexico, USA) and Goddard Geophysical and Astronomical Observatory (Maryland, USA).
◦ Group is continuing to explore methodologies to measure and quantify antenna deformation. Research and continued field tests using laser scanning and terrestrial inSAR have been discussed.
◦ Communicating with team developing deflection of vertical (DoV) measurement capabilities utilizing a robotic total station and camera.
◦ Collection of local tie metadata for the inclusion of the ITRF2020 development.
◦ Updating of local software to allow estimating VLBI and SLR references points from raw survey data into one single processing. Hartebeesthoeck has been reprocessed and a new SINEX file is in development.
Key issues
◦ Investigate thermal and gravitational deformation
◦ Consider importance and inclusion of DoV observations
◦ Consistent formatting and reporting of survey results
