Ionosphere Working Group Progress on recommendations made at the 2016 IGS workshop in Sydney, Australia Presented to the IGS Governing Board and Associate Members on 11 December 2016

To accept CAS-IGG, NRCan and WHU as new Ionospheric Analysis Centers, contributing to the IGS combined VTEC GIMs. The IONEX format shall be updated in order to accommodate contributions from multiple constellation and adequately describe the associated differential code biases Cooperation with IRI COSPAR group for potential improvement of both IRI and IGS TEC. Cooperation with International LOFAR Telescope (ILT) for potential synergies Andrzej Krankowski Ionosphere Splinter Session Summary Recommendations The Splinter session has also included a summary of the activities of the IGS Ionosphere Working Group, updates and future plans especially for introducing GIMs from 3 new IGS Ionosphere Analysis Centers: NRCan,Canada, CAS-IGG, China and WHU, China. Moreover the possibility of adopting the new proposed IONEX format has been discussed. The Ionospheric WG has been informed as well on the ongoing activities characterizing ionospheric variations at different scales from IGS data (such as UWM ROTI polar maps, UPC Solar EUV flux rate proxy).

Progress since Sydney (1) Detailed validation of the three new IAACs has been done (by UPC and UWM). The results have been included in two publications: „Comprehensive assessment of ionospheric electron content models: Methodology and consistency”, M. Hernandez- Pajares, D. Roma-Dollase, A. Krankowski, A. Garcia-Rigo, R. Orus-Perez, already submitted to Journal of Geodesy in October 2016 „Comparing performances of seven different global VTEC ionospheric models in the IGS context” , M. Hernandez- Pajares, A. Krankowski, R. Ghoddousi-Fard, Z. Li, , Y. Yuan, H. Zhang, Ch. Shi, J. Feltens, A. Komjathy, P. Vergados, S. Schaer, A. Garcia-Rigo, D. Roma-Dollase, planned to be submitted in January 2017 also to the Journal of Geodesy) and a few invited talks during international conferences: International Beacon Satellite Symposium BSS-2016 Trieste, Italy, COSPAR 2016, China Satellite Navigation Conference 2016, Changsha, China UPC has prepared computer scripts including proper weighting for the all seven IAACs joined processing purpose. UWM has prepared joined combination scripts. UWM has recently prepared scripts to enable the CAS and WHU IAACs upload their all ionospheric products to CDDIS.

Progress since Sydney (1) VTEC GIMS Std. Dev. regarding JASON* VTEC (daily values, since days 2001.6 to 2016.0) Set#2 of final IGS GIMs (including the resumed and new ones: EMR, CAS & WHU -among the combined IGS and new UQRG-) Set#1 of final IGS GIMs (including those provided since 1998.5: CODG, ESA, JPL & UPC -among the combined IGS and new UQRG-) The discrepancies of all available IGS VTEC GIMS vs +190 millions of altimeter direct VTEC measurements over the seas during the last 15 years, have been analyzed. An overall general agreement is found between the 7 analysis centers, with VTEC discrepancies (daily Standard Deviations) typically ranging from 3 to 10 TECUs, depending on the Solar Cycle phase.

Progress since Sydney (2) The IONEX upgrade activity will be performed by all seven IAACs separately, after including three new IAACs to the IGS structures. The new IONEX format would be introduced after full assimilation of the three new IAACs and will incorporate all-IAACs combined product.

Progress since Sydney (3) UWM along with UPC cooperate closely on assimilation of the IGS ionospheric products (global TEC maps) to the real-time IRI. First results has been shown during invited talks on the international conferences in 2016: International Beacon Satellite Symposium BSS-2016, Trieste, Italy, COSPAR 2016, The publication including first results would be published in the beginning of 2017: „Cooperative GNSS TEC and GIRO NmF2/hmF2 Monitoring for Rapid Real-time Insight in Global Ionospheric Weather, I. Galkin, A. Krankowski, M. Hernandez-Pajares, A. Froń, K.Kotulak The activity has signifficant group of geophyical users interrested in.

Complementing GIRO with GNSS Progress since Sydney (3) Complementing GIRO with GNSS Total Electron Content Peak Electron Density Peak Density Height Slab Thickness Deviation from expected quiet-time behavior

Progress since Sydney (4) The International LOFAR Telescope (ILT) has warmly acknowledged offer of preparing IGS ionospheric products dedicated to the ILT purposes. The activity is performed by UWM and UPC and also CAS in the future. The ILT-dedicated ionospheric product includes increased spatial and temporal resolution (0,5o latitudinal/longitudinal and 15 minutes in time). First regional TEC maps for the years 2012-2016 are being prepared. The new product signifficantly expanded group of scientiffic (geophysical and radioastronomical) users of the IGS ionospheric products. Publication describing new products has been accepted in Acta Geophysica: „Sibsonian and non-sibsonian natural neighbour interpolation of the Total Electron Content value”, K. Kotulak, A. Fron, A. Krankowski, G. Olivares Pulido , M. Hernandez-Pajares, doi. 0.1515/acgeo-2016-0122

Progress since Sydney (4) Comparision of IGS and ILT IONEX regional TEC maps

Progress since Sydney (5) During IGS Workshop, UWM undertook preparing dailly ROTI fluctuation maps as the new IGS ionospheric product (from 2010 up to now). IGS combined fluctuation product results will be shown during IGS Workshop 2017 in Paris. The product will be introduced after 2017 Workshop. The activity has signifficant group of geophyical users interrested in.

Progress since Sydney (5) Monitoring of the TEC fluctuations using GNSS data Evolutions of the daily ROTI maps for 30 May – 4 June 2013

Future Work The combined IGS iono product including all seven IAACs will be uploaded to CDDIS after January 15th. New upgraded IONEX format will be introduced by all (seven) IAACs after the IGS Workshop 2017 in Paris. ROTI ionospheric fluctuation product upload to CDDIS will start in January 2017. The ROTI fluctuation products, similar to the ones prepared by UWM will eventually be prepared by UPC and CAS.

Proposed new members IONO WG since 2017 State Key Laboratory of Geodesy and Earth's Dynamics Institute of Geodesy and Geophysics (IGG), Chinese Academy of Sciences (CAS) Yunbin Yuan is a professor and the director of GNSS Application and Research Group, Institute of Geodesy and Geophysics, Chinese Academy of Sciences. His current works focus on GNSS-based spatial environmental monitoring and analysis and high precision GNSS satellite navigation and positioning. Ningbo Wang received his PhD degree in 2016 at the Institute of Geodesy and geophysics, Chinese Academy of Sciences. His research background is ionospheric TEC modeling technique in terms of algorithm developing and its applications in GNSS precise positioning.

Contact: Andrzej Krankowski kand@uwm.edu.pl Thank You Contact: Andrzej Krankowski kand@uwm.edu.pl