6.16. tileAmplifiers

6.16.1. Purpose

This primitive tiles (or optionally mosaics) the SCI frames of the input images, along with the VAR and DQ frames if they exist.

6.16.2. Inputs and Outputs

mosaic: bool (default: False), tile the images by default; mosaic them (including transformations) if True

dq_planes: bool (default: False), transform the DQ image, bit plane by bit plane

6.16.3. Algorithm

This primitive is a copy of GEMINIPrimitives.mosaicADdetectors with a couple of additional hacks introduced just prior to calling the mosaicing routine, gemini_mosaic_function, and undone immediately after. These are necessary in order to trick the underlying mosaicing machinery into working for GHOST data, and are as follows:

• First, we add ‘GSAOI’ to the internal array of types for our input AstroData object (which contains the extensions we want to mosaic). This bypasses the GSAOI-/GMOS-only check built into gemini_mosaic_function. Afterwards we reset the type list back to normal by invoking AstroData.refresh_types on the resulting, mosaiced, AstroData object.
• Secondly, we set the INSTRUME PHU keyword to ../../../astrodata_GHOST/ADCONFIG_GHOST/lookups. This tricks set_geo_values (called by gemini_mosaic_function) into referencing the geometry_conf.py file under our own astrodata_GHOST/lookups folder. As soon as the mosaicing routine returns we reset INSTRUME back to ‘GHOST’ (and in fact this must be done before the call to refresh_types mentioned above).

Until such time as astrodata_GHOST has been merged into astrodata_Gemini (like GMOS and GSAOI have been), or astrodata_Gemini is refactored, the above two hacks will be necessary in order for GHOST to make use of Gemini’s mosaicing mechanism.

6.16.4. Issues and Limitations

Requires ugly hacks until integration with, or refactoring of, astrodata_Gemini is completed.