Determines the entry time, exit time, and duration of a Spacecraft's pass through the shadow of a central body. Events are reported for Penumbra, Umbra, or Annular shadow condition geometries. If the specified body is a member of the Earth-Moon system, the counterpart not specified will also be considered in shadow evaluation.
The shadow times are determined using a conical shadow. The algorithm to determine the times a Spacecraft is in any portion of the occulting body is shown in the diagram below.
Algorithm used to determine if a Spacecraft is in the occulting body's shadow.
Note: This method uses a spherical model for the occulting body. Use the options available in the VisibilityCalculator to exercise more control over the analysis.