Automated typing of LRIS (BLUE and RED) frames
Version History
Version |
Author |
Date |
|
---|---|---|---|
1.0 |
Debora Pelliccia |
6 Sep 2023 |
1.13.1.dev |
1.1 |
Debora Pelliccia |
10 Aug 2024 |
1.16.1.dev |
Basics
The general procedure used to assign frames a given type is described here: Frame Types.
LRIS frame typing
The primary typing of LRIS frames is performed by
pypeit.spectrographs.keck_lris.KeckLRISSpectrograph.check_frame_type()
.
This function checks the values of various header keywords against a
set of criteria used to classify the frame type. The same criteria are used for
keck_lris_red
, keck_lris_red_orig
, keck_lris_red_mark4
, keck_lris_blue
,
and keck_lris_blue_orig
, unless otherwise noted.
The header cards required for the frame-typing and their associated keyword in the
PypeItMetaData
object are:
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Header Key |
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See below |
lampstat01
is defined using a combination of header keywords, which include
LAMPS
, MERCURY
, NEON
, ARGON
, CADMIUM
, ZINC
, HALOGEN
,
KRYPTON
, XENON
, FEARGON
, DEUTERI
, FLAMP1
, FLAMP2
, FLIMAGIN
,
FLSPECTR
. Since LRIS header keywords have changed over time, the exact combination
of keywords used to define lampstat01
varies depending on the available header keywords.
The criteria used to select each frame type are as follows:
Frame |
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Not used |
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Not used |
Note that PypeIt employs commonly used value of exptime
to distinguish frame type;
however, if needed, the user can specify a different value by
using the exprng
parameter in the PypeIt Reduction File; see also Frame Types.
The science
and standard
frames have identical selection criteria, except for the
exptime
value. In order to better distinguish between the two types, the RA
and DEC
header
keywords are also used to assign the standard
type to frames with RA
and DEC
values that are
within 10 arcmin of one of the standard stars available in PypeIt (see Standard Stars).
The criteria used to select arc
and tilt
frames are identical; the same is true for
pixelflat
, trace
, and illumflat
frames. It’s important to note that
PypeIt is able to correctly assign the pixelflat
, trace
, and illumflat
types
to the internal and dome flat frames, and it tries to do the same for the twilight flats, by selecting
frames that looks like science
frames and include the following words in the OBJECT
or TARGNAME
header keywords: ‘sky’, ‘blank’, ‘twilight’, ‘twiflat’, ‘twi flat’. This way of
identifying twilight flats is not robust, therefore the user should always check the frame types assigned
and manually change them if needed in the PypeIt Reduction File.
Note, also, that if both pixelflat
and slitless_pixflat
frames are identified, the pixelflat
assignment will be removed so that the slitless_pixflat
frames will be used for the flat fielding.
Finally, note that a LRIS frame is never given a pinhole
or dark
type.
Testing
Requirement PLL-16 states: “As a user, I expect the pipeline to automatically classify my data.”
PypeIt
meets this requirement as demonstrated by the tests at
${PYPEIT_DEV}/unit_tests/test_frametype.py
. There is one test
per spectrograph:
test_lris_blue()
test_lris_blue_orig()
test_lris_red()
test_lris_red_orig()
test_lris_red_mark4()
Here is an example of how to run the tests:
cd ${PYPEIT_DEV}/unit_tests
pytest test_frametype.py::test_lris_blue -W ignore
The tests 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 for
all these tests is the same and is as follows:
Find the directories in the PypeIt Development Suite with Keck LRIS data (separately for
keck_lris_blue
,keck_lris_blue_orig
,keck_lris_red
,keck_lris_red_orig
,keck_lris_red_mark4
).For each directory (i.e., instrument setup):
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.
Effectively run pypeit_setup on each of the instrument setups to construct a new pypeit file with the automatically generated frame types.
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
orstandard
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.