Recent advances in real time analysis of ionograms and ionospheric drift
measurements with digisondes

B. W. Reinisch, X. Huang, I. A. Galkin, V. Paznukhov, A. Kozlov, P. Nsumei, G.
Khmyrov

Environmental, Earth, and Atmospheric Sciences Department, Center for
Atmospheric Research, University of Massachusetts, 600 Suffolk St., Lowell MA,
USA


Real time ionospheric data from ionosondes are an important input for space
weather forecasting. Modern ground-based ionosondes provide such data, including
the vertical electron density distribution up to ~700 km, and the velocity
components of the ionospheric F region drift. A global network of digisondes
distributes this information in real time via Internet connections. The quality
of the automatic scaling of the echo traces in ionograms has been a continuous
concern ever since first attempts have been reported. Recent advances in the
digisondeÕs automatic ionogram scaling algorithm ÒARTISTÓ have significantly
increased the reliability of the autoscaled data, making the data, in
combination with models, more useful for ionospheric now-casting. Topside
electron density profiles are adjusted by using IMAGE/ RPI plasmasphere
profiles. Vertical and horizontal F region drift velocities are a new real time
output of the digisondes. The Òionosonde driftÓ is derived from the measured
Doppler frequency shift and angle of arrival of ionospherically reflected HF
echoes, a method similar to that used by coherent VHF and incoherent UHF scatter
radars.

_______________
Submitted to Ionospheric Effects Symposium Proceedings, 2005