Automated typing of DEIMOS frames

Version History

Version

Author

Date

PypeIt

1.0

Kyle Westfall

11 Sep 2020

1.1.1

1.1

Kyle Westfall

18 Sep 2020

1.1.2dev

1.2

Kyle Westfall

28 Sep 2020

1.1.2dev

1.3

Kyle Westfall

14 Oct 2020

1.2.1dev

1.4

Kyle Westfall

28 Jan 2021

1.3.1dev

Basics

The general procedure used to assign frames a given type is described here: Frame Types.

DEIMOS frame typing

The primary typing of DEIMOS frames is performed by pypeit.spectrographs.keck_deimos.KeckDEIMOSSpectrograph.check_frame_type(). This function checks the values of various header keywords against a set of criteria used to classify the frame type. The headers cards required for the frame-typing and their associated keyword in the PypeItMetaData object are:

fitstbl key

Header Key

mode

MOSMODE

exptime

ELAPTIME

lampstat01

LAMPS

hatch

HATCHPOS

idname

OBSTYPE

The criteria used to select each frame type are as follows:

Frame

OBSTYPE

LAMPS

HATCHPOS

MOSMODE

science

'Object'

'Off'

'open'

'Spectral'

bias

'Bias'

'Off'

'closed'

'Spectral'

dark

'Dark'

'Off'

'closed'

'Spectral'

pixelflat

'IntFlat'

!='Off'

'closed'

'Spectral'

pixelflat

'DmFlat', 'SkyFlat'

!='Off'

'open'

'Spectral'

trace

'IntFlat'

!='Off'

'closed'

'Spectral'

trace

'DmFlat', 'SkyFlat'

!='Off'

'open'

'Spectral'

illumflat

'IntFlat'

!='Off'

'closed'

'Spectral'

illumflat

'DmFlat', 'SkyFlat'

!='Off'

'open'

'Spectral'

arc

'Line'

!='Off'

'closed'

'Spectral'

tilt

'Line'

!='Off'

'closed'

'Spectral'

Note that, by default, the exposure time (ELAPTIME) is not used to distinguish frame types; however, this can be changed using the exprng parameter in the PypeIt Reduction File; see also Frame Types.

Importantly, note that a DEIMOS frame is never given a pinhole type. Also note that the criteria used to select pixelflat, trace, and illumflat are identical; the same is true for arc and tilt frames. No distinction is currently made between IntFlat, DmFlat, or SkyFlat and how they’re used in the code.

Also note that PypeIt will ignore frames observed under conditions that do not meet the restricted values set by valid_configuration_values(). This currently requires all frames to have MOSMODE == 'Spectral' and AMPMODE == 'SINGLE:B' or AMPMODE == 'SINGLE:A'. Frames that do not meet these criteria will not be included in the automatically generated PypeIt Reduction File created by pypeit_setup.

Testing

Requirement PD-1 states: “As a user, I want the pipeline to automatically classify my calibrations.”

PypeIt meets this requirement as demonstrated by the test at ${PYPEIT_DEV}/unit_tests/test_frametype.py. To run the test:

cd ${PYPEIT_DEV}/unit_tests
pytest test_frametype.py::test_deimos -W ignore

The test requires that you have downloaded the PypeIt PypeIt Development Suite and defined the PYPEIT_DEV environmental variable that points to the relevant directory. The algorithm of the test is as follows:

  1. Find all the directories in the PypeIt Development Suite with Keck DEIMOS data.

  2. For each directory (i.e., instrument setup):

    1. Make sure there is a “by-hand” version of the pypeit file for this setup where a human (one of the pypeit developers) has ensured the frame types are correct.

    2. Effectively run pypeit_setup on each of the instrument setups to construct a new pypeit file with the automatically generated frame types.

    3. Read both the by-hand and automatically generated frame types from these two pypeit files and check that they are identical. This check is only performed for the calibration frames, not any science or standard frames.

Because this test is now included in the PypeIt Unit Tests (GitHub CI), this frame-typing check is performed by the developers for every new version of the code.