COMPARISONS OF SEVERAL IONOSPHERIC TOMOGRAPHY ALGORITHMS

The rapid development of a wide variety of ionospheric tomography algo rithms has made the selection of an algorithm for a particular purpose difficult and confusing. A set of challenge problems based on observe d ionospheres has been made available to tomography groups. The origin al observed ionospheres were kept secret until after reconstructions h ad been submitted. The comparison of the results from the first challe nge problem offers some insight into which algorithms might be applica ble for a particular situation.