Table 1

CDS vs. DDM: comparison of basic parameters.

Time resolution ∼10 s Typically 15 or 5 min
Spatial information Reflection points are assumed in midpoints between Tx and Rx Location of reflection points is displayed in SKYmaps
Virtual height resolution None. Reflection heights are estimated from ionograms Typically 5 km
Measurement duration Continuous ∼1 min
Sounding frequency Fixed Fixed or related to critical frequencies, programmable

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.