Abstract
The digital pulse ionospheric sounder (Digisonde) of the University of Massachusetts Lowell has been operated in Průhonice (geographic coordinates 50.0N, 14.6E) since 2004 for ionospheric study. Earlier, KEL Aerospace and ISP-42 ionosondes had also been operated.
Hence, there is a long archive of bottomside ionospheric records for a period of about sixty years.In 2009, Topcon NET-G3 triple frequency Global Navigation Satellite System receiver will also be installed at the station, collocated with the Digisonde. GNSS receivers are becoming recognized as another source for ionospheric information.
This year, the upgrade of Digisonde DPS-4 to model DPS-4D also will be realized. This new type will provide a much wider usage and expands the possibilities of our research.
The GPS and Digisonde measurements jointly will bring new improvements to the models of electron density profiles