CpFlatApplyGradientsTask

CpFlatApplyGradientsTask is a task to apply and remove large scale radial and planar gradients in the full field-of-view, with emphasize on LSSTCam flat-fields. This task first requires that CpFlatFitGradientsTask is run twice: first to provide the reference radial gradient that describes on-sky data, and second to measure the radial and planar gradients from a dome flat.

The goal of this task is to adjust dome flats such that at large scales they match the shape of the average sky background.

Processing Summary

CpFlatApplyGradientsTask runs this sequence of operations:

  1. An input uncorrected dome flat is read in and cloned to ensure all calibration metadata is matched.

  2. The coordinates of the flat are projected into focal plane coordinates (millimeters).

  3. All planar gradients fit to the dome flat are removed.

  4. The ratio of the reference radial gradient and the dome flat radial gradient is applied. After this operation the radial gradient on the corrected flat matches the sky, and is suitable to be used as a “background flat”.

Python API summary

from lsst.cp.pipe.cpFlatGradients import CpFlatApplyGradientsTask
classCpFlatApplyGradientsTask(*, config=None, log=None, initInputs=None, **kwargs)

Task to apply/remove gradients for dome flats...

attributeconfig

Access configuration fields and retargetable subtasks.

methodrun(*, camera, input_flat, reference_gradient, gradient)

Run the CpFlatApplyGradientsTask...

See also

See the CpFlatApplyGradientsTask API reference for complete details.

Configuration fields

connections

Data type

lsst.pipe.base.config.CpFlatApplyGradientsConfigConnections

Field type

ConfigField

Configurations describing the connections of the PipelineTask to datatypes

saveLogOutput

Default
True
Field type

bool Field

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