Electron density profiles deduced from GPS TEC, O+-H+transition height and ionosonde data

A new formula of the electron density profiles above the peak height is introduced. The formula is based on the Epstein layer and depends on the O and H scale heights and the OH transition level. Both scale heights have a ratio 1:16 reduced by a factor representing the change from magnetic field line direction to vertical direction. The bottom-side part of TEC (calculated by using foF2, M3000F2 and foE measurements) is subtracted from the GPSderived TEC at the same location. The topside TEC, together with the empirically obtained O-H transition level, are then used to deduce the unknown scale heights. The method is demonstrated on actual data covering low and high solar activity conditions.