DBPapers

COMBINATION OF GPS AND SATELLITE ALTIMETRY DATA FOR GLOBAL IONOSPHERE MAPS

AUTHOR/S: TODOROVA, S., HOBIGER, T., SCHUH, H.
Sunday 1 August 2010 by Libadmin2006

6th International Scientific Conference - SGEM2006, www.sgem.org, SGEM2006 Conference Proceedings/ ISBN: 954-918181-2, June 12-16, 2006, Vol. 2, 265-278 pp

ABSTRACT

In the upper part of the Earth´s atmosphere, the ionosphere, the free-electron and ion density is high enough to influence the propagation of electromagnetic waves. The ionosphere is a dispersive medium for the observables of all space geodetic techniques operating in the microwave band and disturbs both, their group and phase velocity. The effect is in first approximation proportional to the so-called Slant Total Electron Content (STEC) along the ray path and can be corrected if the measurements are carried out at two distinct frequencies, which also provides information about the parameters of the ionosphere in terms of TEC values. For deriving Global Ionosphere Maps (GIM) mainly GPS observations are used so far. Yet, the GPS stations are inhomogeneously distributed, with large gaps particularly over the sea surface. In this work global ionosphere maps from GPS data in two hours intervals have been created and then combined on normal equation level with satellite altimetry measurements. The study aims at the development of an integrated ionosphere model, which should make best use of the advantages of each particular type of data. It is expected to become more accurate and reliable than the results derived by each of the individual space geodetic techniques so far.