BNO C1: GGOS Committee on

Performance Simulations and Architectural Trade-Offs (PLATO)

Chair: Alexander Kehm (TUM, Germany)

Co-Chair: B. Männel (GFZ/TU Berlin, Germany)


The Standing Committee PLATO (Performance Simulations and Architectural Trade Offs) has currently 12 member groups working on simulations and new data analysis concepts covering the full range of existing and projected ground and space assets, including VLBI, SLR, LLR, GNSS, and DORIS. The main focus is on how do we use existing observation capabilities (stations, observation concepts, tracking performance, etc.) including co-location in space with existing and new dedicated satellites or satellite constellations to best support GGOS planning and implementation. Amongst all aspects to be studied, the overall goal is to improve the accuracy and stability of the global geodetic reference frame (terrestrial as well as celestial reference frame) in order to fulfill the GGOS requirement (i.e. 1mm in position, and 0.1mm/y in velocity). The main methods to be applied within PLATO are two-fold:

  • Use simulation techniques to assess the impact on reference frame products of network configuration, system performance, technique and technology mix, co-location conditions, site ties, space ties (added spacecraft, etc.), analysis and modeling techniques, etc.;
  • Use and develop improved analysis methods for reference frame products by including all existing data and available co-locations (i.e., include all satellites and use all data types on all satellites by manifesting satellite co-locations);

Investigations that are part of the PLATO activities include the following aspects:

  • Exploiting the full range of existing observations by ground and space assets:
    • GNSS assets (ground and space)
    • SLR (beyond LAGEOS-1 and -2) including ranging to GNSS satellites;
    • LLR assets
    • VLBI assets including tracking of GNSS satellites;
    • Co-located assets in space (e.g. GRACE, OSTM/Jason-2)
    • Improved GNSS antenna calibrations and clock estimation strategies (GNSS alone or when in combination with SLR, VLBI, and DORIS)
  • Study the impact of anticipated improved performance of current systems:
    • Simulate the impact of upgrading existing stations and their procedures
    • Simulate the impact of additional ground surveys at co-location sites (site ties)
    • Investigate the best handling of a mixture of existing legacy stations and simulated next generation stations
  • Study the impact of potential future space assets:
    • Co-locate all four techniques in space on a dedicated satellite (e.g., concept of GRASP or E-GRASP)
    • Exploit the impact of new observation concepts, e.g. inter-satellite links

Based on the studies carried out within PLATO, recommendations on network configurations, co-location sites as well as on optimal strategies for best-possible reference frame products will be provided.

Committee leads and Membership (could be a link)

• R. Dach, F. Andritsch (AIUB, Switzerland) • D. Thaller (Chair), D. König (BKG, Germany) • M. Bloßfeld, A. Kehm (DGFI-TU Munich, Germany) • M. Rothacher, I. Herrera Pinzon (ETH Zürich, Switzerland) • B. Männel (Co-Chair), S. Glaser (GFZ/TU Berlin, Germany) • J. Müller (IfE University Hannover, Germany)) • D. Coulot, A. Pollet (IGN, France) • R. Gross (JPL, USA) • E. Pavlis (NASA GSFC/JCET, USA) • E. Mysen, G. Hjelle (NMA, Norway) • J. Böhm (TU Vienna, Austria)

Recent progress/Plans

  • Examining trade-off options for station deployment and closure, technology upgrades, the impact of site ties, etc. and project future network capability based on network configuration projected by the BNO or relevant IAG services (IGS, ILRS, IVS, IDS);
  • Investigating the impact of improved SLR tracking scenarios including spherical satellites, LEOs, and GNSS satellites on reference frame products;
  • Investigating the impact of VLBI satellite tracking on reference frame products;
  • Identifying technique systematics by analyzing short baselines, data from new observation concepts, and available co-locations (e.g., consistent processing of LEO and ground-based observations);
  • Investigating the best-practice methods for co-location in space and assessing the impact of co-location in space on reference frame products based on existing satellites and by simulation studies for proposed missions (e.g. E-GRASP);
  • Develop procedures for exchanging simulated observations between software packages in order to cross-validate simulation studies.

Key Publications and Meetings

• Ampatzidis D, König R, Glaser S, Schuh H (2016), The Assessment of the Temporal Evolution of Space Geodetic Terrestrial Reference Frames, IAG Symposia Series, DOI 10.1007/1345_2016_251 • Glaser S, Ampatzidis D, König R, Nilsson T, Heinkelmann R, Flechner F, Schuh H (2016), Simulation of VLBI Observations to Determine a Global TRF for GGOS, IAG Symposia Series, DOI 10.1007/1345_2016_256 • Glaser, S., König, R., Ampatzidis, D., Nilsson, T., Heinkelmann, R., Flechtner, F., Schuh, H. (2017): A Global Terrestrial Reference Frame from simulated VLBI and SLR data in view of GGOS. – Journal of Geodesy, 91, 7, pp. 723-733. DOI: 10.1007/s00190-017-1021-2 • Hofmann, F. and Müller, J. (2018): Relativistic tests with lunar laser ranging, Classical and Quantum Gravity, vol. 35, p. 035015, 2018, DOI: 10.1088/1361-6382/aa8f7a • Hofmann, F., Biskupek, L., Müller, J. (2018): Contributions to Reference Systems from Lunar Laser Ranging using the IfE analysis model, Journal of Geodesy, DOI: 10.1007/s00190-018-1109-3 • Plank, L., Hellerschmied, A., McCallum, J., Böhm, J., Lovell, J.: “VLBI observations of GNSS-satellites: from scheduling to analysis”; Journal of Geodesy, 91 (2017), 7; 867 – 880 • Kehm A., Bloßfeld M., Pavlis E. C., Seitz F.: Future global SLR network evolution and its impact on the terrestrial reference frame. Journal of Geodesy, 10.1007/s00190-017-1083-1, 2017 • Männel B., D. Thaller M. Rothacher, J. Böhm, J. Müller, S. Glaser, R. Dach, R. Biancale, F. Seitz, M. Bloßfeld, A. Kehm, I. Pinzon, F. Hofmann, F. Andritsch, D. Coulot, A. Pollet: Recent Activities of the GGOS Standing Committee on Performance Simulations and Architectural Trade-Offs (PLATO) • Otsubo T., K. Matsuo, Y. Aoyama, K. Yamamoto, T. Hobiger, T. Kubo-oka, M. Sekido, U. Hugentobler, R. König: Effective expansion of satellite laser ranging network to improve global geodetic parameters. Earth Planet Sp 68, 65 (2016). • Pinzón I.H., Rothacher M. (2020) Co-location of Space Geodetic Techniques: Studies on Intra-Technique Short Baselines. In: International Association of Geodesy Symposia. Springer, Berlin, Heidelberg. • Pinzón, I.H., Rothacher, M. Assessment of Local GNSS Baselines at Co-Location Sites. Journal of Geodesy, Berlin: Springer, 2018. • Plank L, Hellerschmied A, McCallum J, Böhm J, Lovell J (2017), VLBI observations of GNSS satellites: from scheduling to analysis. J Geod, Springer, doi:10.1007/s00190-016-0992-8 • Schuh H, König R, Ampatzidis D, Glaser S, Flechtner F, Heinkelmann R, Nilsson T (2016), GGOS-SIM – Simulation of the Reference Frame for the Global Geodetic Observing System, IAG Symposia Series, DOI 10.1007/1345_2015_217 (last update 09.2020)