Advances in Radio Science www.adv-radio-sci.net 1684-9965 1684-9973 2 Kleinheubacher Berichte 2003 2004 10.5194/ars-2-283-2004 http://www.adv-radio-sci.net/2/283/2004/ http://www.adv-radio-sci.net/2/283/2004/ars-2-283-2004.html http://www.adv-radio-sci.net/2/283/2004/ars-2-283-2004.pdf 283 287 2005-05-27 35 years of International Reference Ionosphere – Karl Rawer’s legacy D. Bilitza Raytheon ITSS/SSDOO, GSFC, Code 632, Greenbelt, MD 20771, USA This presentation is given in honor of Prof. Karl Rawer’s 90th birthday. It looks back at 35 years of research and development in the framework of the International Reference Ionosphere (IRI) project. K. Rawer initiated this international modeling effort and was the first Chairman of the IRI Working Group. IRI is a joint project of the Committee on Space Research (COSPAR) and the International Union of Radio Science (URSI) whose goal it is to establish an international standard model for the ionospheric densities, temperatures and drifts. This year we are celebrating Karl Rawer’s 90th birthday and also the 35-year anniversary of the IRI effort. My talk will review the close involvement of Karl Rawer in all stages of the development and improvement of this international standard from early on and his still very active participation in this effort.