Updating the Local Model of the TEC during the Solar Eclipse on August 11, 1999

A total solar eclipse with the locations and times of the pass well-known in advance can be used to update the local model of the TEC for these particular circumstances. The observations using GPS receivers at the Warsaw and Borowiec stations and the ionosonde in Warsaw were analyzed in order to justify the results given by the IRI theoretical predictions. The IRI program with this updating creates a useful tool for preparation of the corrections for the process of network adjustment using the GPS technique and for navigation using single frequency receivers.