libera_utils.geolocation.sub_solar_point#

libera_utils.geolocation.sub_solar_point(target: SpiceBody, et: float, frame: SpiceFrame, observer: SpiceBody, *, abcorr='LT+S', method='NEAR POINT/ELLIPSOID')#

Computes the cartesian coordinates of the subsolar point at ephemeris time et.

Parameters:
  • target (spice_utils.SpiceBody) – Body on which the sub point will be calculated (usually a planetary body).

  • et (float or numpy.ndarray) – Ephemeris time of observation.

  • frame (spice_utils.SpiceFrame) – Reference frame for returned vectors.

  • observer (spice_utils.SpiceBody) – The object from which to calculate the subsolar point (e.g. a spacecraft). A-B correction is applied based on the distance between observer and subsolar point.

  • abcorr (str) – String delineating what kind of A-B lighttime correction to perform. Default is ‘LT+S’.

  • method (str) – String specifying what kind of method to use to find the vector between the observer and the target. Default is NEAR POINT/ELLIPSOID, which uses the nearest point on the ellipsoid rather than drawing a line through the center of the ellipsoid.

Returns:

Subsolar point on the ellipsoid surface in the specified reference frame, apparent epoch at that point (depending on specified light time correction), and vector from observer to subsolar point.

Return type:

numpy.ndarray, numpy.ndarray, numpy.ndarray