Availability Times

Access can only be computed for times when each object of the pair is available. The available times are computed by determining the interval overlap between each object’s availability time intervals. Available times depend on the object type:

• Ground locations, Area/Line Targets, and Stars are considered to be always available
• Vehicles are only available during their ephemeris span (i.e., the time interval over which the vehicle has a defined position and attitude)
• Children objects incorporate the availability of their parents as part of their availability
• Targeted Sensors, Targeted Receivers, Targeted Transmitters, and Multi-Function Radars may have instrument on-off times
  • These objects are deemed off when there is no access to any targets, and so are unavailable for those times.
• Ephemerides for Planets are normally available for about 100 years and so are considered to be always available, though one should be careful not to ask for access outside a Planet’s ephemeris span.

Each object is able to report its Availability intervals using the Availability Times data provider within the Report Manager.