Global Navigation Satellite System (GNSS) IGS Weekly Ionosphere Vertical Total Electron Content (VTEC) Grid Validation Product from NASA CDDIS

Analysis Centers (ACs) of the International GNSS Service (IGS) retrieve GNSS data on regular schedules to produce independently computed VTEC maps. The IGS Ionosphere Analysis Center Coordinator (ACC) uses these individual AC solutions to generate the official IGS VTEC maps. The validation products are used to compare the IGS and AC solutions of generated VTEC maps.

There are three types of ionosphere product evaluation/validation products: 1) the upcwWWWW.YYv.Z files provide an evaluation of the final weekly combination solution of VTEC maps with the individual analysis center contributions; 2) the gpsgDDD0.YYi.Z files are provided by the Center for Orbit Determinate (CODE) at the Astronomical Institute at the University of Bern (AIUB) Switzerland; these files contain GPS broadcast ionosphere model for day YYDDD; and 3) the ckmgDDD0.YYi.Z products are computed by CODE using their Klobuchar model, best fitting CODE’s final ionosphere solution, also available from the CDDIS.