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Ground Visibility

Ground visibility produces a predicted pass schedule for satellites over selected ground locations, for planning contact windows with ground stations and for predicting passes for ground-based sensors.

Visibility requests are created through the Satcat API or Satcat SDK.

Primary Data Sources​

A spacecraft's trajectory for visibility analysis is defined by one of:

  • A TLE (Two-Line Element) set
  • An ephemeris_id from Catalog Data

Observers​

A visibility request predicts the visibility windows of one or more observers to selected satellites. An observer is a ground station or a sensor location, defined in one of two ways.

  • Ground station: latitude, longitude, and altitude, with an optional maximum elevation angle.
  • UDL sensor location: a sensor defined through the Unified Data Library (UDL) sensor API. UDL sensors carry azimuth and elevation visibility constraints per sensor, so they support constraints a simple ground station cannot express.