Skip to main content
Announcing GCN Classic Migration Survey, End of Legacy Circulars Email. See news and announcements

Instrument Pointing

Instrument pointing and rotational rates.

View the source on GitHub

Properties

* = required

NameTypeDescription
ranumberRA pointing of the instrument Z axis
decnumberDec pointing of the instrument Z axis
rollnumberRoll [deg] of the instrument about its Z axis
position_anglenumberRotation angle [deg] between the spacecraft X-Z plane and the plane defined by the spacecraft X-axis and celestial North
attitude_quarternionarrayRepresenting attitude state of a spacecraft, using four element vector [q1, q2, q3, q4], composed of a scalar and 3 element unit vector.
rotation_ratearrayRotational rate [rad/s] about the X, Y, and Z axes respectively
timestringTime [UTC, ISO 8601] of this data, if different than the trigger time.

Example

{
  "$schema": "https://gcn.nasa.gov/schema/v3.0.0/gcn/notices/core/Pointing.schema.json",
  "ra": 120.5,
  "dec": 30.2,
  "roll": -12.8,
  "position_angle": 23.7,
  "attitude_quarternion": [
    0.2,
    0.3,
    0.4,
    0.5
  ],
  "rotation": [
    -0.01,
    0.05,
    0.02
  ],
  "time": "2022-05-08T13:30:00Z"
}
Looking for U.S. government information and services? Visit USA.gov