StarID.project_stars

giant.stellar_opnav.star_identification:

StarID.project_stars(image, image_number=0)[source]

This method queries the star catalog for predicted stars within the field of view and projects those stars onto the image using the camera model.

The star catalog is queried using the query_catalog() method and the stars are updated to the epoch specified by image.observation_date using the proper motion from the catalog. The queried Pandas Dataframe containing the star catalog records is stored in the queried_catalog_star_records attribute.

After the stars are queried from the catalog, they are converted to inertial unit vectors and corrected for stellar aberration and parallax using the position and camera_velocity values. The corrected inertial vectors are stored in the queried_catalog_unit_vectors.

Finally, the unit vectors are rotated into the camera frame using the a_priori_rotation_cat2camera attribute, and then projected onto the image using the model attribute. The projected points are stored in the queried_catalog_image_points attribute.

If requested, the formal uncertainties for the catalog unit vectors and pixel locations are computed and stored in the queried_weights_inertial and queried_weights_picture. These are computed by transforming the formal uncertainty on the right ascension, declination, and proper motion specified in the star catalog into the proper frame.

In general this method is not called directly by the user and instead is called in the id_stars() method.

Parameters:

  • epoch – The epoch to get the star locations for

  • compute_weights – A boolean specifying whether to compute the formal uncertainties for the unit vectors and the pixel locations of the catalog stars.

  • temperature – The temperature of the camera at the time of the image being processed

  • image_number (int) – The number of the image being processed

  • image (OpNavImage)