@article{TUW-120430, author = {Todorova, Sonya and Hobiger, Thomas and Schuh, Harald}, title = {Combination of GPS and satellite altimetry data for global ionosphere maps.}, journal = {Proceedings of the International Scientific Conference SGEM 2006}, year = {2006}, volume = {2}, pages = {265--277}, keywords = {Combination, GPS, satellite altimetry, ionosphere} }