Free Access
Fig. 1.
Directions to the north and to the positions of the source and the spacecraft form a spherical triangle. This establishes the relations between the angles of the problem. Here Δβ is the angle between the projections of vectors r and rM on the equatorial plane.
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.