| Description: occultation_direction indicates the direction of an occultation track as observed. Permitted values are 'ingress', 'egress', 'both', and 'multiple'. This attribute refers to the observed occultation track overall, not to the subset that might appear in a product such as a derived ring profile. For example, if an observed occultation includes both ingress and egress portions, each of those two portions will usually be represented by its own derived ring profile which will have occultation_direction set to Both and ring_profile_direction set to Ingress or Egress as the case may be. Required in labels of ring occultation observations. Not intended as a value for a table field. |
| Namespace Id: rings | Steward: rings | Class Name: Occultation_Time_Series | Type: ASCII_Short_String_Collapsed |
| Minimum Value: None | Maximum Value: None | Minimum Characters: 1 | Maximum Characters: 255 |
| Unit of Measure Type: None | Default Unit Id: None | Attribute Concept: None | Conceptual Domain: SHORT_STRING |
| Status: Active | Nillable: false | Pattern: None |
| Permissible Value(s) | Value | Value Meaning |
| | Both | The projected distance to the target body center along a portion of the occultation track decreases with time, and along a different portion increases with time. |
| | Egress | The projected distance to the target body center increases with time. |
| | Ingress | The projected distance to the target body center decreases with time. |
| | Multiple | The occultation track is not monotonic over relatively short time scales. Examples may include 1) certain space-based occultations in which the star takes an irregular apparent path, or 2) extremely long duration occultations of a high proper motion star. |