| Description: spacecraft_event_time indicates the instant at which an event occurred at the spacecraft, e.g., the arrival or departure of a photon. Required table field for radio occultation data, but not used in stellar occultation data. The time is given in numeric seconds as an offset from the specified UTC reference time. The reference time is preferably the start of a day, and is required to be given in the label using the attribute reference_time_utc. Additionally, in radio occultation labels the corresponding time interval end point values are given by the required start_spacecraft_event_time_utc and stop_spacecraft_event_time_utc attributes. |