Volume 15, Number 3, September 1999
By Dieter Bilitza
The annual task force activity of the International Reference Ionosphere (IRI) at the International Center for Theoretical Physics (ICTP) in Trieste, Italy, on June 28 - July 2, 1999, resulted in several improvements of the IRI electron density model. The activity, now in its sixth year, tackles a number of very focused and specific modeling questions with the help of data and tools accessed over the Internet during a week-long meeting of about a dozen experts. Of special importance is the much better representation of the equatorial ionosphere since this region has the largest impact on waves propagating through the ionosphere. This model improvement was possible because of the use of modern digisonde software with data from several ionosondes from the equatorial region. The results are a good example for the benefits of collaboration among scientists from developed and developing countries; one of the primary goals of ICTP (http://www.ictp.trieste.it/ ) is to enable such activities. The presentations during the task force activity are published in ICTP Reports. Meetings summaries together with the references for the reports can be found on the IRI home page http://nssdc.gsfc.nasa.gov/space/model/ionos/iri.html.
IRI was developed and is being updated by a joint working group of the primary scientific unions dealing with ionospheric science, the Committee on Space Research (COSPAR) and the International Union of Radio Science (URSI). It is the most mature of the empirical ionospheric models having undergone testing with many data sets and being used by a wide range of users for a multitude of applications. It is the defacto international standard for the ionosphere. The international organization in charge of standards is the International Standardization Organization (ISO). Its TC20/SC14/WG4 is responsible for standards for the Earth environment (Technical Committee 20: Aircraft and Space Vehicles; Subcommittee 14: Space Systems and Operations). Following an invitation from this ISO body, the IRI team presented a proposal to make IRI the ISO standard during the recent ISO/TC20/SC14 Meeting in Turino, Italy (May 10 -14, 1999). The proposal was received favorably by the participants and a new ISO Work Item was initiated. The road from an ISO Work Item to the final standard is, however, a long one and is complicated in the case of the ionosphere because of a counter proposal from Russia (SMI-88).
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