FgcmMakeLutTask

FgcmMakeLutTask computes a look-up table tracking atmosphere and instrumental variations for use in the fgcmcal fits. The intention is that this is run once for a given observatory/instrument and should only be updated when instrumental parameters change (e.g., updated filter and ccd throughput curves), or in the extremely rare case if an observatory is relocated to a different elevation or latitude.

This is the first task in a typical fgcmcal processing chain. The second is FgcmBuildStarsTableTask or FgcmBuildStarsTask, the third is FgcmFitCycleTask, and the fourth is FgcmOutputProductsTask.

FgcmMakeLutTask is available as a command-line task, fgcmMakeLut.py.

Processing summary

FgcmMakeLutTask uses an input atmosphere table (preferable) or a list of atmosphere parameters, combined with the instrumental throughput as a function of position, to compute a look-up table used in the fgcmcal fits.

fgcmMakeLut.py command-line interface

Note that no --id arguments are used by fgcmMakeLut.py.

fgcmMakeLut.py REPOPATH [@file [@file2 ...]] [--output OUTPUTREPO | --rerun RERUN] [other options]

Key arguments:

REPOPATH

The input Butler repository’s URI or file path.

See also

See Command-line task argument reference for details and additional options.

Python API summary

from lsst.fgcmcal.fgcmMakeLut import FgcmMakeLutTask
classFgcmMakeLutTask(butler=None, initInputs=None, **kwargs)

Make Look-Up Table for FGCM...

attributeconfig

Access configuration fields and retargetable subtasks.

methodrun(**kwargs)

Run task algorithm on in-memory data...

methodrunDataRef(butler)

Make a Look-Up Table for FGCM...

See also

See the FgcmMakeLutTask API reference for complete details.

Butler datasets

When run as the fgcmMakeLut.py command-line task, or directly through the runDataRef method, FgcmMakeLutTask obtains datasets from the input Butler data repository and persists outputs to the output Butler data repository. Note that configurations for FgcmMakeLutTask, and its subtasks, affect what datasets are persisted and what their content is.

Input datasets

camera

Camera geometry and detector object

transmission_optics

Optics transmission curve for the instrument

transmission_filter

Filter transmission curve (as a function of position) for the instrument

Output datasets

fgcmLookUpTable

FGCM atmosphere and instrument look-up table

Retargetable subtasks

No subtasks.

Configuration fields

atmosphereTableName

Default
None
Field type

str Field (optional)

FGCM name or filename of precomputed atmospheres

connections

Data type

lsst.pipe.base.config.Connections

Field type

ConfigField

Configurations describing the connections of the PipelineTask to datatypes

parameters

Data type

lsst.fgcmcal.fgcmMakeLut.FgcmMakeLutParametersConfig

Field type

ConfigField

Atmosphere parameters (required if no atmosphereTableName)

physicalFilters

Default
[]
Field type

str ListField

List of physicalFilter labels to generate look-up table.

saveLogOutput

Default
True
Field type

bool Field

Flag to enable/disable saving of log output for a task, enabled by default.

saveMetadata

Default
True
Field type

bool Field

Flag to enable/disable metadata saving for a task, enabled by default.

stdPhysicalFilterOverrideMap

Default
{}
Field type

DictField

Key type

str

Value type

str

Override mapping from physical filter labels to ‘standard’ physical filter labels. The ‘standard’ physical filter defines the transmission curve that the FGCM standard bandpass will be based on. Any filter not listed here will be mapped to itself (e.g. g->g or HSC-G->HSC-G). Use this override for cross-filter calibration such as HSC-R->HSC-R2 and HSC-I->HSC-I2.

Examples

See the cookbook for worked examples.